Destructimus

I was just curious as to what the maximum reccomended horsepower you can put through a 700r4 transmission is, why you can't go beyond that without it breaking, and ways you can reinforce the transmission to make it capable of handling additional horsepower. Also, I'm wondering if putting a new torque converter onto your car is something that i could do at home without too much difficulty or expensive tools. Thanks.

Destructimus

Hey, while I'm at it I might as well ask another question, this one about my differential. Lately it seems like I've been getting a lot more tire spin than normal, and it's only from one wheel. I swear it seemed in the past like I had a posi. I recently had a new pinion seal put on because my differential was leaking. Is there anyway in this process that my differential could've been screwed up or damaged from regular wear and tear and if I do have a posi, how can I fix this problem?

performabuilt

The weakest links in the 700R4 ae the 3-4 clutch set and the sunshell . Both of these along with other mods done during a build and the 700r4 can handle considerable HP . We have cars running in the low tens and some other have cars in the low 9s with the 700 built correctly its a tough trans

Mikz86TA

iTrader: (4)

Abuse is the main reason....or a botched rebuild. X2 on the 3-4 clutches and sunshell. Ive had one of those break B4. Ruined my weekend and lightened my wallet too. About the diff........you need to find out what you have. A limited slip does use clutches ans tension spring/springs. They can wear out. A torsen or Gov-Loc are a little different. Open is a one-wheel peg leg. If youve never had it replaced or upgraded and its stock, look to your RPO in the glovebox. G80 is usually the code for a locker/posi/limited slip. GU# or GT# is the ratio code. Replacing the seal wouldnt hurt it. Low on gear oil and not adding friction modifier (if L.Slip) could cause failure

Pro Built Automatics

The 3-4 clutch pack has always been a weak point, the sunshell is on the list, and the lack of lube to the rear planet has been a problem in the pre 1991 units. I have had solutions for all of these for many years now. I use the late GM heat treated sunshell and or the Beast sunshell in all of my builds and rebuild kits without any failures. The lube problem (rear planet failure) was solved back in the early 1990's with the use of the Viton input to output shaft seal in every 700R4 buildup and or rebuild kit. The 3-4 clutch setup has not been a problem since 1995-1996 when I went with the Borg Warner Hi-Energy 8 clutch setup, and in the early 2000's the Borg Warner Hi-Energy (4L65E) 9 clutch and sometimes a 10 clutch setup. I have always used the TransGo Performance Shift kit modified to get smooth part throttle shifts with firm WOT shifts. This might surprise most, but all of my 10 or 9 second transmissions (except one) has the Corvette servo and the Borg Warner Hi-Energy 2-4 band. GM has done the vast majority of work here when it comes to improvements in this transmission, it just needs to be tweaked some.

Shagwell

how true. - there have been many revisions made through the years. Each one improved upon the last. There's a reason why '93 cores are so nice to find.

I've got one behind a blown big block in a custom built 81 chevy shortbed truck that carries the front end through low gear.

Mikz86TA

iTrader: (4)

On my 1991 date coded tranny, what do I have (if left by the previous rebuilder) that is upgraded? Anything aparticular in the 3-4 pack, sunshell or palnetery set? What year did they go to the 5-pinion planetary set? And hardedned sunshell? Is the 'Beast' shell an aftermarket part or is it just a re-marketed GM/Hydramatic part? Also, ATSG recommends that you leave the 3-4 Load Release Springs off. Says its for a better 2-3 shift and 3-4 durability. Does the 91 have those stock? And what were they orig intended to do. Whats your take on it? THX...sorry for 200 questions. I like to learn and apply

duckmanquacker

the 5 pinion planets and hardened shells I believe were introduced in 1993. the BEAST is aftermarket. what ATSG calls Load Release springs others call them boost springs, these were intended to boost the apply and release of the 3-4 pack. 88 and up had these stock.

Mikz86TA

iTrader: (4)

OK...so if I do this ful rebuild later, should I leave them off if applicable? I found out my tranny has the 2050 friction plates by the model ID. Or it was suposed to. Anyone have any info or input on that. If I do Alto 3-4 clutch pack does this make a difference? Also t shows a modifying technique to the Pumps Press. Regulator Valve..or buy the one that already has it # 8684048. What does that do, and is it recommended? Explain why the 91 has a Bellville Plate? THX =)

duckmanquacker

not sure if the ALTO plates are any better but they are good. I dont see the pressure regulator mod you speek of in my books but that doesnt mean it not worth doing, any help in the pressure dept. is good. as far as the bellville plate it is supposed to have better spring pressure for the 3-4 pack than the wave plate had.

Mikz86TA

iTrader: (4)

Cool THX. The eg mod is on page 95 figure 174 in the ATSG 87-93 700R4 manual. I found mixed thoughts by people when I Googled it. I looked it up by the replacement GM part #8684048. Which has the mod already done. Basically the 2nd land from the top or the 1st thinner land is ground down on the sides making it no longer round. From what I gather it was to resolve a 'noise' issue from the pump whining. Ill probably leave it alone if mine isnt already done. Ive never had any whining issues and there seemed to be a couple possible setbacks from it.

Pro Built Automatics

The GM 3-4 load release springs should not be removed if you are not changing the 3-4 clutch count. They help prevent the clutches from coming on from centrifuge. If you are going to change the clutch count, (which is always a good idea) to 7, 8 or 9, then you cannot use the GM 3-4 load release springs. You will need to install the TransGo Hi Rev Spring kit. This will allow you to use any clutch setup. I install these in all of my 700R4/4L60E units. They allow faster/cleaner 3-2 downshifts, and keep the 3-4 clutches from accidently applying in first or second gear at high rpm from centrifuge. The 5 pinion planets came out in the 4L65E, and are not necessary. The 4 pinion planets are not known for their breakage. The BW #2050 3-4 clutches were the first generation Hi-Energy clutches and were very good. The second generation Hi-Energy clutches came out in 1995-1996 and are still used today. I use use them in all of my 700R4/4L60E units, and in TH400's. I use the aftermarket pressure regulator valve from Dean Mason. He designed this valve while working for TransGo in the 1980's for the 2004R, and the 700R4. This valve requires no modifications to be done to it. I have not found the Alto clutches to be equal to the Borg Warner clutches anywhere on these units. There is a waved steel from Alto that is to replace the Bellville plate in the reverse/input drum. I use these in all of my units, as it does not tear up the reverse/input drum like the Bellville does. The late GM heat treated sunshell works very well, and is lighter than the Beast, and is balanced. I have never had a failure with either. With 650FWHP and more, I recommend you Cryo the output shaft. With the input drum you can add the steel sleeve when getting into high HP, or a serious 4WD setup. This keeps the drum (not very common) from splitting open.