327_TPI_77_Maro

iTrader: (8)

Hi guys, I picked up a 700R4 that is a GM reman with supposedly super low miles on it. It is behind a very strong EFI 327. Anyhow, it shifts normally at light throttle (except the shifts are sooooo soft you can not even feel them, it basically "rolls" from one gear to another). All gears work. At full throttle, the shifts are still extremely soft and it still rolls from one gear to another (It has the least positive shifts I have ever felt, you'd laugh if you heard this thing shifting, I also think 1st-2nd flares a little).

What the heck? I was thinking the TV valve is having an issue (the TV cable is new and it does adjust properly, so I know it has tension on it from the TV valve, it's not like anything snapped from the cable to the TV valve). BUT the car will kick down properly, so I figure the TV must be doing something.

So it seems my line pressure must be low? Other than a plugged filter (which I will check, I have not had the pan off yet, I stuck the trans in the car just to make sure it worked), what else could cause such soggy non positive shifts on a low mileage trans?

I have rebuilt some non OD auto trans' before but I have never had a transmission shift this soggy before.
Thanks

Steve

Randy82WS7

is the cable pulling the valve very far ? the cable is set right ?

hmmmm

327_TPI_77_Maro

iTrader: (8)

The cable is set right , and the cable/TV plunger are going full travel.

If I kick the gas at part or full throttle the trans downshifts immediately, so it looks like the TV is doing is job...the shifts are just unbelievably soft. It's like each shift just slides right into the next gear. I'm not talking about normal buick/cadillac soft shifts. It's like each shift takes a second and the revs gradually fall off from one gear to the next.

Jay

iTrader: (2)

Do you know what the transmission originally came from? year and model?

YenkoST

iTrader: (5)

I had the same thing go one with mine about 4 years ago. To fix the problem, I added a shift kit and servos. Fixed the soft issue and now is shift crisp.

327_TPI_77_Maro

iTrader: (8)

Jay, it's from a 91-92 Suburban with a 350. These are not normal soft shifts, something is slipping at WOT. The shifts are really really soft and the 1-2 shift will flare. This is not just a matter of application having a soft stock shift. I have driven other stock 700R4's and even the soft stock shifts are still "positive" feeling.

YenkoST

iTrader: (5)

My 700r4 reman was not a positive feel shift. It felt more like a slip with 5 miles on it....so I had to put a shift kit in it...once I did, everything was great. Been running on it for 36k now. Have you pulled your pan to check for metal just in case. While I was in there, I would do a shift kit just to see if that helps...heck you can get one for $35 bucks.

Shagwell

I'd agree, it's a stock reman. I've personally seen 2 Gm remans in the last year that had to be warrantied due to problems, one of which the vehicle just suddenly stopped moving. The local Gm dealer took it apart to find that the builder had not put a snap ring on the sprag.

Put a decent(superior or transgo, NOT B&M) shift kit in and see what happens. If that doesn't correct the problem, well, then atleast you have a good shift kit when you go to pull the trans apart.....

Also, many stock remans are softer than factory because people complained about stock shifts being to firm. You have to remember that factory items are built for the general public that are all starting to drive toyota's and honda's.

327_TPI_77_Maro

iTrader: (8)

The $35 shift kits are very incomplete. When I do kit this I will be using the Transgo kit. I have already purchased a corvette servo kit and a Superior governor reprogramming kit.

If you guys who are telling me the sloppy shifts are normal drove my car you'd change your mind. I have a high mileage 700R4 in my 85 TA and it is totally stock and shifts great.

Shagwell

ahhh, when I try to reply to a thread it won't give me the box to type a message in! _ anyone got any ideas? I've got to use the quick reply

anyhow, the superior kit is like $40 from PATC and includes the servo springs, the accumulator springs, all shift passage valvebody springs, and the .470 boost valve for the pump. The instructions tell you which passages in the vb seperator plate to drill to what size, and which check ***** to put where(and which to omit). It works VERY well. Nice firm crisp shifts that get progressively firmer the more throttle is applied.

AS for the stock reman vs the stock 85 unit, as I was saying, the newer units from GM have the shifts backed off to avoid people complaining about harsh shifts. The comon person would be more happy with a vary drive and no shifts. - If the trans is not assemble wrong or worn and the TV is adjusted properly, the next thing to check would be the accumulator springs. If you're going into it that far, then put a shift kit in it while you're there. - FYI I have seen stock accum springs that were broken, thus would cause very weak shifts.

327_TPI_77_Maro

iTrader: (8)

Yeah I have to drop the trans beacuse I'm getting a custom 10" converter, so I will tear down and inspect the clutches and bands. If that all looks good I'll put a kit in it and put it back together.

You think the Superior kit will be enough, and that the much more expensive Transgo really won't do anything different? Sounds like I'll just get the Superior kit then. Also do you know if the Superior kit will give me WOT 3-4 shifts?

The unknown year high mileage 700R4 behind the gutless LG4 lays down rubber doing the 1-2 shift at WOT on dry pavement, each time, every time. The thing shifts fantastic. I bought the transmission for $40 and was just happy that all the gears worked, but it feels great. I wish the trans I am working with in the Camaro right now worked as well.

FearThisGTA

I know you said the tv cable is adjusted right, but thats usually a clear sign of a impropper tv cable adjustment. There's alot of info on this site hth

327_TPI_77_Maro

iTrader: (8)

Fearthis, that is a good link. I am very clear on how the TV adjusts--I'm getting the cable to click out after depressing the D tab and then going full throttle. It sounds like this trans is going to need at least a partial tear down to figure out what the hell is going on with it. I am going to get a pressure gage to see for sure at least what the line pressure looks like.

weeoh5

one other possibility is that you have a mismatch of parts cable/bracket/throttle arm. I know that the cable is different for a carb application vs an FI application. I had a 700R4 that wouldn't shift right behind a carbed 350 in my 71 Nova...the trans was out of a TBI car and until I got a bracket and cable for a carbed 700R4, it would "adjust" but the trans still didn't shift right. I know this isn't your exact scenario...but just make sure that your cable is for a TPI car.

good luck with it

327_TPI_77_Maro

iTrader: (8)

The cable is for a TPI car, I realize all the applications get different cables. Even some of the carb 4bbl qjets get different cables depending on the year and application, it's really weird.

Pat Hall

iTrader: (31)

It's pretty unlikely the Superior shift kit has the part you need to achieve WOT 3-4 shifts. The Corvettes and the cop cars got a different TV sleeve to make them do this. You can buy the right sleeve for about $50 bucks, but there's really no point in spending all that money since you can modify the existing sleeve to do the same thing. All you have to do is block two of the holes in the sleeve by tapping them, putting set screws in the holes with some loctite, then grind the heads flush with the outer diameter of the sleeve. It's a piece of cake to do, and there's a message thread on here somewhere with pictures of how to do it. Do a search on the forums and you should be able to find it. All you have to spend is a few bucks for the tap and a couple of set screws. I put the B&M 3-4 kickdown sleeve in my trans a long time ago, which helps by delaying the downshift until 2/3 throttle instead of 1/2 throttle, but it still won't stay in 4th at WOT. Since my original sleeve was sitting on my workbench, I went ahead and modified it. I'm going to be putting a Transgo shift kit in soon, and I plan on putting the modified sleeve in at that time. It sucks when you're going over 100 mph and mash on the gas a little more, and all of a sudden the trans downshifts into 3rd. My motor jumped to almost 5k! I definitely recommend using the modified sleeve. I have to agree, your trans definitely has issues. My 700r4 has 235,000 miles on it, and it still kicks like a mule when it shifts.