ASE doc

I had my trans built 13 years ago to withstand heavy duty use behind my 450HP engine. I damaged 3rd gear twice and had to have it redone. They got it right the third time and it has worked beautifully ever since. Friday I had it at the dragstrip and lost 3rd gear on a hard 6,500rpm up shift. Now, I want to be sure that I do everything i can to beef up the trans, especially 3rd gear, to prevent any further failures. I have researched this on the net and found some hardened parts and five pinion planets. I also remember using one sided clutches. What else can I do? Any suggestions are appreciated.

RPOL98

for starters, i'd recommend the ATSG book on the 700R4, i got a copy from Summit (under TCI) for about $30, i've also seen it on eBay for about the same price, new.

ASE doc

Oh yeah. We had those for every trans we did at Gearmasters back when I was a partner there. I do plan on buying one. I have been doing alot of research on the web. Anyone serious about building a solid 700R4 should check out the PATC website. Those guys have really done their homework on this trans.

One part that they feature is made by Sonnax and called the Smart Tech input drum. The 3-4 clutch installs at the very rear of the input drum and in factory form is held in place by a snap ring. The backing plate for the 3-4 clutch is fairly thin and flimsy. This backing plate flexes alot, especially with high line pressures common in high performance trans buildups. This flexing allows the clutch plates to flex as well and reduces the clutches torque capacity. The Smart Tech drum does away with the snap ring and replaces the weak backing plate with a sturdier bolt on backing plate that doesn't flex. Deleting the snap ring also allows room for extra clutch plates and steels.

I plan on using this piece in my trans repair along with a Superior 2-4 servo. This will beef up 3rd gear and 2 nd gear as well. I'll also install the heavy 1-2 accumulator spring to solve the crash 1-2 shift(at low speeds and low throttle pressure) that's plagued me ever since the trans was built 13 years ago and is caused by removing the 1-2 accumulator spring with some shift kits.

morgsie

iTrader: (1)

I highly recommend going with one of Dana's kits: http://700r4l60e.com/

ASE doc

Thanks for your response. I have checked out Pro Built's website. They do build some very stout transmissions. I firmly believe though, from my own experience and from every 700R4 I have ever seen broken behind a built motor, that without addressing the inherent flaws of the 3-4 clutch design, there is no way to make this clutch pack live long behind a serious motor. Add high rpm, high pressure shifts to this equation and you are guaranteed to be replacing your 3-4 clutches way sooner than you want to. The Smart Tech drum is the first real solution I have seen to this problem. I won't be surprised if within the next few years, this part starts showing up in all high performance 700R4 builds.

ASE doc

I've pretty well put together my parts list. This doesn't include any hard parts that I may find need replacement as I go into the unit. These are just the up grades that I will be doing. These are all parts that weren't available when the unit was built in 2000.

1. Smart Tech input drum(every high performance 700R4 should have this part)
2. Smart Shell reaction shell
3. Superior 2nd and 4th servos
4. Induction hardened input shaft
5. 25/8" Wide Kevlar Band and new reverse input drum
6. Heavy 1-2 accumulator spring(to solve 1-2 crash shift created by earlier shift kit)
7. High rev pump slide spring(to maintain full pump flow at high rpms)
8. Red Eagle Power Pack 3-4 clutch pack(9 full thickness clutches with 8 full thickness Kolene steels)

This parts list represents about $1,100 in parts alone with the addition of rubber, paper, sealing rings, and clutches. This may seem like alot but what I've learned from my experience is that you can pay to do it right once or you can pay to do it over and over again. With these upgrades, this transmission should be solid for a long long time, regardless of how hard I drive it.

Pro Built Automatics

The Alto Red & Alto Commercial 9 clutch setup is what was very popular back the mid 1990's, and it did not hold up very well, especially when the horsepower went up or the when driving got aggressive. I solved the 3-4 clutch problems back in the mid 1990's when I started using the Borg Warner Hi-Energy 3-4 clutches in place of the Alto clutches. I increased the stock clutch count of six to eight. This proved to work out very well. Having many vehicles using this setup going 11's & 10's (at that time) in the 1/4 mile successfully. When the 4L65E 3-4 setup came out, I went with a nine or ten clutch 3-4 setup. These were going into nine second to low ten second vehicles and Pro Street vehicles, and were holding up extremely well. The Sonnax drum is probably a good piece, but as stated the 3-4 clutch problems that I have are rare, so I do not find it necessary to use it. The Smart sunshell is good and I have used them, but the failure of the encased bearing is very rare from my experience. I use the Sonnax 2nd apply servo as it has the "cushion" springs and the Superior does not use them. It is much harder to get a smooth part throttle shift with the Superior 2nd apply servo. The Sonnax 4th servo has a much larger apply area than the Superior setup, and will keep the 2-4 band alive on 3-4 WOT shifts. As for the "induction hardened input shaft", I have never seen an input shaft fail from a properly built unit. So if it does not cost to much, and you have a very firm 1-2 shift at all throtlle openings, then it might be worth the extra cost. The Alto extra wide 2-4 band is alright, just use the Red or Carbon band, not the Kevlar. I prefer the BW Hi-E 2-4 band in all but the highest horsepower applications. When using the "extra wide" band the reverse/input drum must be perfectly flat (have very low miles, less than 35,000) or a new oem drum must be used for it to work properly.

ASE doc

Thank you for your response. From what you're saying, I gather that the 4L65E input drum has more capacity for the 3-4 clutch? To hear that you've run the OE style drum(not the smart drum) in 10 second cars makes me rethink my strategy. $500 will buy alot of parts. I have been looking at the Sonnax servo. I like that it has double o-rings and looks like a better design. I was going to install a 1-2 accumulator spring to address the crash 1-2 shift I have had since the trans was built.

How do you install the turbine shaft and stator shaft sealing rings? I'm looking at tool options and wondering if I can get around buying the pricey factory tools.

gp90gta

iTrader: (1)

I buy most of my parts from these guys.

Pro Built Automatics

The input drum 1987 and later had the same internal spacing for the clutches. The 4L65E came with seven 3-4 clutches instead of six. They did this by making the clutches slightly thinner and the steels slightly thinner. I offer the "step cut" solid input shaft teflon rings. These require no special tool to install them. The stator shaft rings are a scarf cut and are easy to install without any tool. To help you solve the harsh 1-2 part throttle shift, I need to know what valve body kit you are using (if any) and the separator plate feed hole size for the 2nd gear, and what 1-2 accumulator valve spring (in the valve body) is being used.

ASE doc

I was on your website last night after reading your post. I have been on your site quite a bit over the last few weeks. I was referred to it by a member of another forum. The shift kit is a Trans Go. It is the level 3 I believe. It allows me to hold all gears to 6,800 rpm and full manual control, while also providing auto shifting. The trans was built, to the best of the builder's ability, with every available upgrade in 1999.

The 1-2 accumulator, I'm quite sure, has no spring. These kits came with the option of replacing the spring with washers. I forget how it went, something like 3 washers for milder shift, 2 washers for hard shift. I believe this is why I have such a harsh 1-2 shift at low speeds, auto shifting. Manual shifting, when I let the speed get up to 25mph, the shift is firm but not bad. I prefer the firm shifts, I just don't like the crash. Sometimes it hits so hard it bounces 2 times like a shuttle shift. I'm sure it's just the internals being slammed and rebounding.

My car is not a 10 or 11 second car. With slicks it could probably pull low 12s. I do however shift at 6,500 and have been known to down shift from 2-3 at full throttle when passing just for fun. I am concerned that this shifting style may be part of the cause of my 3rd gear issues.

How long have the units lasted that you built for high HP applications? Do they have 3rd gear issues at the end of a race season? I have thought that the Smart tech drum would give the 3-4 clutch pack an edge to help it hold up a little better.

ASE doc

I forgot this thread entirely. I must have made that last post before tearing down my transmission. On teardown I found some interesting things. The 3-4 clutch pack was the Alto 9 thin frictions and 8 thin steels. The frictions and steels were badly coned and burned up. A check ball, the one for the 3rd clutch, had beaten up the case and separator plate, since steel ***** were used. I think that check ball may have been stuck, preventing the 3-4 clutches from even engaging. The 2nd accumulator did have a spring. It's a spring with a very high coil count like I haven't seen before. I haven't noted what spring is in the 2nd accumulator valve of the VB. I misunderstood what Pro Built said. I was thinking of the accumulator spring itself. Ill check that out. I have my parts in hand and I am about ready to start the build.

gp90gta

iTrader: (1)

The 3-4 clutch burnup on the 700r4 is very debatable subject with all the top trans builders, most of the ones I've seen with thin more clutch setups seem to overheat the metals, if your not going to spend the money for the Sonnax smart-tech housing then I would go with the thicker metals and less clutchs array.

ASE doc

I did get the Smart tech drum. The people I bought it from like the Alto clutches with kolene steels. The Smart tech along with the 4L65E 3-4 apply ring, the 4l65e apply ring is just barely shorter to allow more 3-4 clutch capacity, allows for 9 frictions and 8 steels that are thicker than the thin pack that was in the trans before. I am still thinking about going with Borg Warner high energy though. I think you could fit a 9/8 set of these in the Smart tech also without getting too thin on the frictions and steels and it sounds like they hold up better. I think also helpful for my application is that I will be u s ing the high rev springs and the 4L65e release springs to prevent centrifugal apply at high shift speeds. I think that the 3-4 return springs that were in there weren't doing it. Especially with one broken spring. I am curious to see how my shifts turn out. I did go with the Superior servos. I hope that wasnt a mistake. Has anyone ever heard of blocking the line bias valve?

gp90gta

iTrader: (1)

Yep I've read the Borg Warner's are the way to go but I won't lie, I never used them so I can say, I've been stuck on the red eagles and kolelne's for about six years now but the thin array warps the metals like nobody's business, got a bunch here if you want to see pic's, Sonnax site says you can run 9/8 or 8/7, the only reason I say to go with 8/7 is I've read the ss impala guy have much better luck with more metal, I think they even run thicker then the 8/7 setup, and that one heavy mother of a car.

TTOP350

iTrader: (8)

I have been thru 15 700r4s trying different things over the last 20 years with my car. (most were just a stock rebuild behind a decently powered car with a nutty driver)
I finally have a trans that will hold the 2-3an3-4 full throttle upshifts at 7,500rpms.
I think number 7. on your list, (High rev pump slide spring to maintain full pump flow at high rpms) is a big help with my past failures. I also purchased a 03-04 truck trans for all the roller parts and the 5 pinion planets to put in my older trans.

This was my last trans failure. I run a blanket and other stuff because that one came thru the floor right by my knee and left a 8" long gash in the floor. Sounded like a shot gun went off.

Pro Built Automatics

Contrary to popular belief, it is the clutch material that is the problem, not the steel. The clutch material holds oil that is used to disperse heat on the 2-3 shift. If the clutch material does not hold enough oil (such as Alto), it can start the clutches to glaze. This can happen quickly, which is a common complaint. Now the glazed clutch material will no longer take in oil or release oil, and no longer disperse heat as before. Now it will lose the holding capabilites that it started with, will start to slip, generate even more heat that can no longer be dispersed as before , now the clutches & steels get hotter & hotter, and the slip starts to get progressively worse. Now the steels form heat (leopard) spots and or surface melt, then can warp. In otherwords this clutch pack is "history". On tear down you might or might not find warped steels. The steels will only warp from the clutch losing its ability to dissipate heat. The steels never warp on their own. Once the clutch goes, then the steel follows.
In drag racing, or street use the BW Hi-E 8 or 9 clutch pack with the thin steels will work fine, and has worked out very well over many years. From my experience, I have found the Borg Warner Hi-Energy clutches to hold the most oil. The Hi-Energy clutch material from Borg Warner is available in .080", .067" & .062" thicknesses (+-.002"), and works extremely well in all applications. You can put together 6, 7, 8, 9 or 10 clutch setups using the Hi-Energy clutch material from Borg Warner. In terms of durability here, the Hi-Energy 3-4 clutches has proven to be the best. Close behind is the Raybestos. I have used the Borg Warner Hi-Energy clutch and band material (2nd design) since their introduction, with a high degree of success.
Now Raybestos offers different types of clutch material other than Hi-Energy, their Blue Plate Special and Z-Pak clutch setups for certain applications.

gp90gta

iTrader: (1)

No arguments here and I by no means consider my self a pro trans builder, almost all of trans builds have done stock rebuilds, here at Honda since 93 but I did work for GM before that and have done a few aod's, 727's, A500's and some other rear wheel unit that I can't think of right now. To me it just makes sense that if the metal plates are thicker they can absorb more heat not to say that the clutch plates don't play a major part in, and thank you help and contribution, I always learn as much as I can, that last post was very informative.

ASE doc

I know very little about transmissions. They have never been my specialty and I didn't even build my own the last time. I had it done. I have learned alot this time by researching and listening to people like Dana from Pro Built. Bless the power of the internet. The part about the 3-4 apply ring change on the 4L65E I just found out two weeks ago. I was trying to find the apply ring stamped "7" that Sonnax specifies for use with the Smart Tech. I spoke with a tech from Sonnax and he referred me to a tech sheet from ATSG that details the upgrades made in 2001 for the 4L65E. One of the changes was a slightly shorter, I'm talking about .080", apply ring. The shorter ring makes just a little more room for the 3-4 clutch pack.

There are so many differing opinions on how to build this clutch pack to handle rough use. Dana swears that his hold up even with thin clutches and a stock drum. He obviously knows what he's talking about. I got the smart tech because I want to do everything possible to make this trans last this time. Plus, the input housing, aside from blowing up, is a hard part that will last for the life of the unit through many rebuilds. Dana swears by the BW High Energy clutches while others swear by the Alto Red Eagles. I guess each of us just has to make the choice for ourselves. I went with the Red Eagles because the people I bought the Smart Tech and my other pieces from swear by them and offer a setup designed just for the Smart Tech. GM used the BW High Energy in the 4L65 from the factory. I may end up running to PTW in Portland and grabbing a hand full of High Energy clutches. One difference I know of from past experience is that the High energy clutches absorb alot of fluid. The Red Eagles don't. Maybe this helps the High Energies handle heat better.

I mentioned blocking the line bias valve because I read an article published by another performance trans builder saying how this is the first thing he does to beef up 3rd gear. The line bias valve bleeds line pressure above 1/2 throttle. I suppose GM did this to prevent shift harness at high throttle openings, though no one has been able to tell me the exact reason. I blocked mine using a cut off piece of 1/8" drill bit. Cant remember the exact length but I think it's .890". Ill try to find that article and let others know where to find it. The piece of drill bit just holds the valve closed. I also went with the Superior servos. I hope that the 1-2 shift isn't to harsh. I am going to a 2,800 stall from my current 2,300 I hope this will absorb a little shift shock and I'm hoping that the larger apply area will slow the apply just a little. I got the larger servos because I want max apply pressure. As I said, I'm curious to see how the trans shifts. I may end up pulling it back out to redo some of these things. I hope that it shifts very firm at all speeds.

The vast array of high test parts for these units available today is amazing. My parts list totaled $1,600. The guys at PATC in Louisiana gave me everything for 1,400 and change including shipping. They were also very helpful and are installing all of my sealing rings and pressing the Smart Tech onto the hardened input shaft for me. I'm excited to put this beast together.

EDIT: Duh, I didn't see ProBuilt's last post before I wrote this. What he said.

gp90gta

iTrader: (1)

Not sure about the bias valve but I would think that if it has a harsh 1-2 shift then a softer 1-2 acumulator spring should smoothen it out without loosing line pressure, but I don't have the hydronic schematic in front of me to get a better look at what's going on, maybe some else can chime in on it and help out.

ASE doc

I was thinking that the trans may not have had an accumulator spring at all. I remember that the TransGo 2-3 kit gave the option of deleting the spring. Mine did a have a spring. It was not super stiff but its coil count was so high that it could only have compressed 1/4" or so in the bore, which would have really limited the accumulator travel. I'm going to try the brown spring which is a stiff spring. We'll see how it works out. At least the VB and accumulator can be removed for recalibration with the trans installed. Unfortunately, the servos on a third gen can't be.

For Pro Built, the accumulator valve train has a black fairly firm spring. Don't know what shift kit was used. The 2nd feel hole is .125". Thank you for your help.

ASE doc

I also did some research and the accumulator valve in my trans is .394. That is much larger than even the largest(.341) offered by Sonnax. My concern about going to a smaller valve is how does this affect apply pressure. Does it only soften the shift or does it bleed apply pressure? I think I would rather manual shift to avoid the bang than reduce apply pressure.

gp90gta

iTrader: (1)

From what I've read about acumulators is that is supposed to cushion the shift, that's why it's an acumulator, fills with fluid, not bleed off, could do that with a valve.

Pro Built Automatics

One difference I know of from past experience is that the High energy clutches absorb alot of fluid. The Red Eagles don't. Maybe this helps the High Energies handle heat better. Exactly....

For the line bias valve, I use the red spring from TransGo to help firm up the shift. I do not like blocking it as I want the valve to be progressive. If you are using the TransGo regular Shift kit or the Junior Shift kit, use the "black" accumulator valve spring with the "B" or "A" accumulator valve. The "B" is the most common in 1988 and up 700R4 transmissions. The Sonnax accumulator valves "M", "L", or "K" were for when you use a single spring instead on the over/under spring setup that are use in the TransGo Senior & Junior Shift kits. In otherwords if you use the HD "single spring" from Sonnax in the 2nd accumulator, then you would use one of the "M", "L", or "K" valves to keep the part throttle shifts smooth. If you want the smoothest 1-2 part throttle shifts, (you still will have quick WOT shifts) and you are going to use one of my Shift kits or TransGo's Senior or Junior Shift kits the "A" accumulator will give you the best part throttle shift and the "B" the next best along with the black spring from TransGo or a weaker oem spring or no spring at all. If you are going to use the 700-2-3 Performance Shift kit "as is", then you will need the Sonnax HD spring and one of the Sonnax accumulator valves to get the desired part throttle shifts. Remember accumulators are similar to shock absorbers as to what they do. If you are trying to find the "A" accumulator valve, they are most often found in 1982-1986 700R4 valve bodies, the same with the "M","L", or "K" valves. In 1999 I worked with Maura at Sonnax to get the "M", "L", & "K" valves made as TransGo was still using a "single spring" on the 2nd accumulator (and not the over/under setup as they are now using) to get a smooth part throttle shift as the "B" was way to firm on part throttle shifts. Superior, Art Carr, B&M and others drill the 2nd feed to .125" which is way to large. Even in my 750HP & up setups I use .110" at max. For street use I never go over .099" with .096" being the norm with 9.5" torque converters.

ASE doc

Thank you Pro Built for the excellent response. I'm not sure what shift kit my trans has. It is obviously not the transgo 2-3 kit that I remember. I am planning to purchase the Sonnax accumulator valve train. I was going to go with the M-K(.341) valve. It comes with three different springs for calibrating shift firmness. From what you're saying I gather that this change will simply soften part throttle shifts and won't reduce apply pressure on the 2nd servo. I an ashamed of myself that I came this far on this project and overlooked this component. But this is a learning process afterall.

ASE doc

TTOP350, Judging from the smoke show I see in the photo, I think I know what killed your trans. Lol, maybe I'll have that kind of power eventually. Gotta talk my wife into letting me build that engine. By then I definitely hope to have a trans that will handle it.

ASE doc

Mr Pro Built, I have a question regarding the line bias valve. You mention the valve being progressive. Are you saying that it creates progressively firmer shifts with increased throttler pressure? I had the opposite impression from what I read. I will see if I can find the red spring from Transgo.

TTOP350

iTrader: (8)

How you really "beef up" a 700r4

ASE doc

Okay, I have new information. Anyone who knows better, please feel free to correct any misstatements I make here. The Line bias valvetrain is designed to bias line pressure rise to match the engine's torque curve. It is intended that line pressure should rise the most during the first 50-65% of throttle opening, as this is where engine torque increases the most in stock applications. My engine is not stock and I have always noticed with this trans that my 2-3 upshift felt a little soft right at half throttle, in fact I hated this and would manual shift to avoid it, and I think it's because the line bias in the trans was too soft at that point for my modified engine. Blocking the line bias valve in place takes this torque curve matching out of the equation so that line rise will be more linear and increase with throttle opening from closed throttle to WOT.

I see where a stiffer spring or even blocking the valve in place would be an improvement over this factory tuning. I have mine blocked in place right now waiting to go back together and I'm tempted to try it this way. I can always change it later if it's a problem. It would only be that my shifts would be too firm at high throttle openings.

ASE doc

Do you mix the beef noodle soup in the fluid? At .65 a can that could be the cheapest fix ever. Lol

Pro Built Automatics

Depending on what gear ratio you have in the rear end and what stall and diameter torque converter you are running will determine which valve "M", "L", or "K" you will need to use here. OR you could go with the TransGo Junior Shift kit (which is what I add to the 700-2-3) and that will let you add back the cushion spring (which you removed when installing the 700-2-3) to get a smoother 1-2 part throttle shift along with the over and under spring setup for the 2nd accumulator to go along with the "B" accumulator valve that you most likely have now. If you take off the valve body then add the RED spring to the line bias valve.

IROCgiraffe

iTrader: (3)

subscribed.

skirkland1980

iTrader: (2)

The failure in post #16 looks like the input drum exploded solely due to excessive rpm (it's only aluminum). Would have appeared more catastrophic but the case was shielded by the reverse input housing and the band.

Pro Built Automatics

What came apart was the sunshell going to a very high rpm. This is caused by the input sprag from slipping. I have seen this a few times over the years, not all taking the case apart, but hitting the inside of the case and trying to split the case in half. Now for the different applications as to where to use the thicker steels.
On the use of thicker steels. In Road Racing where there is much cycling (2-3, 3-2, 2-3, 3-2, shifts in a short period of time), then the use of thicker clutch steels to act as a "heat sink" are required. Even though the fluid is removing the heat, the steel cannot disperse it fast enough before the next (cycle) shift occurs. The aluminum input drum helps out here to disperse the heat.
In drag racing, or street use where there is not a lot of cycling, then the 8, 9 or 10 clutch pack with the thin steels will work fine, and has worked out very well over the years.

ASE doc

Thank you again for the great information. I had the Borg Warner dual cage sprag in my trans and it looks to be in perfect shape. I'm going with the Beast sunshell too for extra strength. I ordered the Transgo JR kit today that comes with the red line bias spring. It's a $38 kit and has several springs that may come in handy in the build. I'm also using the brown 2nd accumulator spring. I ordered the "M" accumulator valve train to replace the "B" valve train that's in the valve body now.

Pro Built, what is your opinion of 13 vane pumps? Do they really break as easily as I've heard? I'm thinking of going with one instead of the 10 vane I have now.

TTOP350

iTrader: (8)

For what its worth I have a 13 vane in my car now, it hits 7,500 rpm all the time and I do drive it normally once in awhile.. I think I have around 5,000 miles on it so far..

ASE doc

Yeah, I'm a little irritated. The box my new pump came in says "13 vane with .500 boost valve". Inside t h e box was a 10 vane pump with a .471 boost valve. I'm going to hit the supplier up about this.

Pro Built Automatics

Since you are going to use the TransGo Junior Shift kit you DO NOT want to use the "M" accumulator valve. Save your money. The "B" or "A" is what you want when using the over/under accumulator spring setup. With the "M" accumulater valve using the Junior kit will give you a way to soft of a part throttle shift. The reason TransGo went to the over/under setup was that the vast majority of valve bodies from 1988 & up had the "B" accumulator valve. The old dual spring (red & yellow springs) on one side of the accumulator piston setup that TransGo used was designed to work with the M, L, or K accumulator valves that came in the old pre-1988 valve bodies. When using the "B" accumulator valve use the black spring with it to give the best 1-2 part thottle shifts, when using the Corvette servo. There is nothing to be gained using a 13 vane setup where a 10 vane was the original. You would have to mofify the back half of the pump and use the 13 vane slide to get out of it what it was designed to do. The 10 vane setup will give you all you need. With the 13 vane you actually lose a little volume as the rpm goes up.

ASE doc

Thank you for your help. I am still a little confused on the accumulator valve train but I'll read the instructions with the Jr kit and try to figure it out. If I have any more questions, I know who to ask. I guess I will stay with the 10 vane pump. Unfortunately, I already rdered and paid for the "M" accumulator so too late to save the money.

Now I have another question. I was told this morning that when using the later style 3-4 release springs that go around the clutch pack, you don't need the early style 3-4 clutch return springs that go on the 3-4 piston. I was thinking I would use both sets of springs but If this would be excessive then I won't go that way. What do you suggest?

Pro Built Automatics

If you change the 3-4 clutch pack count, then you have to use the HD springs from TransGo. Do not use the factory return springs on the outside when using the TransGo HD springs. These HD springs help make a cleaner 3-2 downshift also. I always install them in all my applications. Install "all" the springs in each area. Do not leave any out. Set the band clearance to the minimum, as this helps the 2-3 shift. In the 700R4 set the 3-4 clutch clearance to .035" - .055" when using the Corvette servo. Try to return the "M" accumulator valve or sell it. If you use the "M" accumulator valve, use the orange accumulator spring in the valve body, and a .093" - .096" 2nd feed hole size with a 9.5" torque converter, and with a 12" TC a .082" 2nd feed hole size.

ASE doc

Thank you again Pro Built for your great information. I just had a tech at Transgo tell me that there is no way that the 3-4 clutch pack in a 700R4 will ever survive long when it's run to 6,500rpm very often. He said at that speed, the inner lip seal on the 3-4 apply piston begins to bleed pressure and the 3-4 clutches will slip and burn. I think I got on his nerves a little when I asked if there was anything I could do to fix this. He said that with this unit, that's just how it is. That wasn't good news. He also said that with my trans setup the way it is, without the 2-3 shift kit, he didn't see how it could hold each gear to 6,500. But it does. Now I'm really curious about that too. I guess it must be the Corvette governor. I know it has the Transgo TV valvetrain and 3-4 shift valve at least.

zz17iroc

iTrader: (4)

Dana knows what he is talking about, I've been running his street strip kit behind my nitrous breathing 383 low 10/high 9's sec car for at least 8yrs now.

Pro Built Automatics

Well I have had many transmissions and have helped others that have motors going well over 6,500 rpm, making the 2-3 shift and living. Right now there are three units going over 8,000rpm. Yes, that seal can do what TransGo says, but I can't remember the last time it happened. Getting the transmission to hold first gear to over 6,000 rpm without the 700-2-3 is very rare, as the governor and valve body shift timing springs and valves usually need to be addressed to get it to do this.

ASE doc

You certainly have my attention and trust. I know my trans doesn't have the Transgo 2-3 kit because I've done this kit before and would recognize the mods that are done with it. I expected to see these mods when I opened the unit up, but was surprised to see a new valve body replacing the modified VB I had it the trans before. In fact, the trans that I pulled out of the car isn't even the same case that I had before. On top of the unit was written " City of Portland" so I'm guessing this is a trans built for a police vehicle.

There are obviously many mods done but all apparently in the form of valve train changes. For instance, the line bias spring when I went to change it out for the red spring from the JR kit, is an orange or maybe brown spring, not the pink that I thought I remembered. The spring has a high coil count and is very stiff. Just as stiff as the red Transgo spring. I pulled the blocking pin that I had put in it before out.

The trans really has worked great, therefore I planned on pretty much leaving the VB alone. But I'm severely OCD, especially when it comes to my baby, so I get to thinking and then things get crazy. There are just a couple of issues that I was thinking could be addressed. These include upgrading the OE 3-4 springs to prevent centrifugal apply, I got the 7-CS spring kit today. Then there's the 1-2 light throttle bang shift which I will try to solve by reducing the size of the 2nd clutch feed orifice in the seperator plate and changing the accumulator spring. I'm going to leave the accumulator valve train alone. Then I was playing with the line bias valve which maybe isn't even an issue. With a new pump and all new sealing rings, maybe I'll have better pressure and the slow ***** at 1/2 throttle won't be an issue.

I really appreciate your help and all of the great input on this project.

Pro Built Automatics

What accumulator valve do you have now and what spring is with it?

ASE doc

I left the B valve in as you instructed. However, I didn't put in the black spring from the JR kit. I left the black spring in it that was already there. It's alot stiffer than the black spring that came with the JR shift kit. I know that this may cause my bang shift at low throttle to continue but I always lived with that before and the 1-2 shift everywhere else was excellent. Am I being dumb? If so tell me.

I had to admit that I have no idea what the prior builder did to this transmission. Aside from maybe slacking on the 3-4 clutch set up, they did a great job. I don't know for sure how they made it hold every gear to the engine's 6,900rpm rev limit, but they did. I guess I've decided that aside from swapping the accumulator spring and the clutch spring changes to help 3rd gear, I am reluctant to change anything. You and others have asked me what kit was used in this trans and I honestly can't tell you. Only that it works pretty darn well.

I put the high rev transgo 3-4 and forward clutch springs together tonight and swapped the 3-4 check ball capsule for the orifice that came with the high rev springs.

Cool news. I ordered the rest of my parts today and the sales person made it pretty painless. Now, everything is covered. One thing that I thought of tonight is my TCC solenoid. I think I'll get a new one for this build. Otherwise, all my parts are handled. I am also pretty stoked right now. The job of pressing my hardened input shaft into the Smart tech housing is done. I practiced on my old shaft and housing, pressing the shaft out and back in. I made sure that I got everything jigged up straight and that that all went well. Then I jigged up the new housing and shaft the same way and it went together perfectly. I also installed the reinforcement ring. Then I made up a sealing ring installer using an empty water bottle and a hose clamp and I installed the sealing rings on the input shaft. It turned out really well.

The trick is to use plenty of white lithium grease so that the rings slide down the plastic smoothly. Then align them into the grooves and work them into place with your fingers. Then finally, lube the inside of the plastic with grease and wrap it around the ring. Use a hose clamp over the plastic to compress the ring into the groove. The tool for this job is $154 at the cheapest I could find. I spent $1 on the water bottle. I already had the grease and the hose clamp. If I did this professionally, I would definitely buy the tool. Since this will be the last 700 I build until I have to do this one again someday, my makeshift set up was fine.

One tool that I think is pretty much a necessity for this assembly though is the right spring compressor. I used the press and jigged up a makeshift compressor for the tear down but I don't feel comfortable assembling the unit this way. Especially with the stiffer high rev springs going in. I ordered the KD universal spring compressor from my Cornwell rep. It looks like it will work fine for all the springs in the 700. Hopefully he'll get that to me by the time my clutches show up.

34blazer

all you need is some pics of what you did and this would make a great sticky

sub'd

ASE doc

I'll shoot some pics next week of the setup I used. Ive also heard of using a piece of hose with a clamp around it. I liked the water bottle plastic because it's clear so you can see the sealing ring through it.

Pro Built Automatics

You want to use the "black spring" from TransGo, as it is weaker or no spring at all and this will make the part throttle shifts smoother. It will not change the WOT shift. You do not want or need a hard part throttle shift, as it is hard on the gear train, attracts cops, dangerous in the rain, hard on anything splined and the biggest reason of all "women hate it".

ASE doc

Thank you for your response Dana. Let me clarify just what the 1-2 shift was doing, it would bang shift if I took off slowly from a stop with very light throttle and let the trans shift at minimum 1-2 shift point. If I gave it just a little more throttle and brought the car`s speed up just a little, the shift would be firm but not unreasonably. Any throttle position above 15 or 20%, the 1-2 shift was great. I read that swapping to the M accumulator valve was a solution to this but if there`s any chance of it softening the shift above 20% throttle, I`d rather leave it alone. The only woman that rides in my car is my wife and she loves it just the way it is. I guess she`d like it better if it didn't`bang shift at all. Do you think that the softer spring will fix the bang issue with no unwanted side effects? Am I correct in thinking that the accumulator valve controls how much pressure is sent to the accumulator? That it doesn't actually affect fluid to the servo itself?