johns88z28

why do people put corvette servo's in camaro tranny's ? what does this do?

IWANNAROCAGAIN

The corvette servo firms up the 1-2 shift. I have one, but haven't put it in yet

johns88z28

how would i know what year servo to buy? my trans is from 86.

johns88z28

what year servo should i buy for an 86 trans?

IWANNAROCAGAIN

The Corvette servo for the 700r4 trans.

you can get it from here, www.700r4l60e.com/

guys name is Dana, he really knows these transmissions and how to improve them!

slowmaro87

to add to the OP's questions is it difficult to swap in the vette servo?

johns88z28

thanks for the info ill check it out for surely

camaronewbie

It's a PITA to install - but not really any worse than anything else. It installs in the pass side, where that round cover is. You have to have a nice long prybar, and use some ingenuity. The cover has to be pushed inwards, and held there, while a large snap ring is removed. You accomplish this by prying against the tunnel (fulcrum) and using the prybar (lever). It's really a 2 man job - not sure one person can do it alone - it takes alot of force to hold that cover in while removing and installing the large snap ring.

You might be able to get a scissor jack in there and use it to push in the cover now that I think about it - it's been a few years since I did mine.

johns88z28

thanks for the help i will hopefully be doing mine soon if i can find the right servo

Stevolwevol

iTrader: (1)

I believe a corvette servo will keep your tranny from shifting from 4th in to 3rd at higher speeds.

IWANNAROCAGAIN

No, I believe that is controlled by the 3-4 servo thats in the valve body area. All the corvette servo does is firm up the 1-2 shift,

I have a shift kit with all these parts in it that I haven't installed yet, mainly because its just a pain in the a$$ to work on the tranny in the car!

Stevolwevol

iTrader: (1)

Then I might just have a corvette servo in my IROC. I have a firm 1-2 shift. Any more adjustment and my line pressure is too low to kick it down into 1st from 2nd. Are they visible from the outside of the tranny?

IWANNAROCAGAIN

It's very possible someone put one in, they're very cheap, like $20 or so. No you would have to remove the side cover and remove the whole servo assembly to check, and honestly getting that cover off is a major PITA!!

Stevolwevol

iTrader: (1)

Well, the 1-2 shifts are great. Firm, but not enough to snap a u joint or a neck.

IWANNAROCAGAIN

Sweet! Then you may indeed have the vette servo!!!

Pro Built Automatics

The reason the Corvette servo was designed by GM was to eliminate the 2-3 flare shift. The Corvette servo is the 3rd accumulator here. By allowing more oil to go to the 3-4 clutches it eliminated the 2-3 shift flare. The 1-2 shift now would be firmer, but the feed hole size and the 2nd accumulator setup was changed to keep the 1-2 shift from being too firm. With the 553 servo, it was easy to make the 1-2 shift firm. The problem was making the 2-3 shift with any kind of horsepower. The Corvette servo solved this. The Corvette servo has nothing to do with the 3-4 shift, the 1-2 and the 2-3 shift only.

Stevolwevol

iTrader: (1)

What exactly do you mean by flare shift?

Pro Built Automatics

It is where the engine breaks away, revving up between the 2nd and 3rd shift. If it is bad enough, you have to let off of the throttle to make the 2-3 shift. A "slight" flare at WOT will not do any damage in most cases, but a big flare can destroy the 3-4 clutches in short order. Best shift is no flare at all at WOT.

Stevolwevol

iTrader: (1)

I experience no flare at all w/either car, and I have had each at wot. Is this characteristic of r4's or earlier models? My 87 Silverado had an r4, and had no flare either.

IWANNAROCAGAIN

A tip to get that side cover off:
if you are replacing the servo and have new o-rings, once you get the snap ring out using a pry bar or big flathead screwdriver, pry the cover out slightly with a small flathead screwdriver and take needlenose pliers, pull the blue o-ring out a bit, cut it and pull it out with the pliers, the cover can then easily be removed by wiggling it back and forth and forward with either visegrips or pliers!
I did it that way and it was a 5 min job to do!

RBob

iTrader: (1)

Consider yourself fortunate. The 2-3 flare can be an real problem. The opposite can also happen, a 2-3 bind. This is the only shifting between two gears in the 700R4 that the timing is critical. The flare or bind can happen on either an up shift or a down shift, or both.

Consider an up shift from 2nd to 3rd. The 2/4 band gets released as the 3/4 clutch pack is applied. If too much time takes place between the two operations the result is a flare.

If the 3/4 clutch pack gets applied before the 2/4 band is released, the trans binds.

It can be a real balancing act to get the two operations timed properly. And as the band and 3/4 clutches wear, the timing changes.

RBob.

Pro Built Automatics

Ford C-6's and Mopar TF8's from years ago had the same problem here as the 700R4 and 4L60E. TransGo had different solutions for these units too, that worked very well. Yes, it is a "fine" balancing act here.

regal301

install the vette servo,sonnax elevated pressure reg spring and .500 o-ring'd boost valve.it really wakes up the 700r4.

its not hard to do,you may have to lower crossmember for more room.and the cover may be stuck,so soak with pb blaster and keep pushing on it. DONT PRY ON THE TRANS HOUSING AROUND THE SERVO COVER !!

heres a guide for the install.

http://www.gmfullsize.com/forum/showthread.php?t=98029

Rumblin70SS

Hello all,

I have what appears to be the 2-3 flare shift issue. The 1-2 shift is firm, but 2-3 hangs when at the track and I do let off slightly to get it into 3rd. This has to be costing me a 1-2 tenths even on my stocker.

In reading this, it looks like the Corvette servo should fix this issue. I have an 88 5.7 IROC, and I was under the impression that these cars got the Vette servo. Am I mistaken or do I have another problem?

The car is a little slow switching from reverse to drive going upon startup and when its cold out, but other than that it runs and drives great.

Any help is appreciated!

Pro Built Automatics

Some had the Corvette servo, most did not. Adding the servo should fix this if this is minor, othrwise the modified TrandGo Shift kit will address this if the 3-4 clutches are still in good shape.

Stevolwevol

iTrader: (1)

This is an old thread, so I have to be briefed a bit. At WOT I redline to shift from 1st to 2nd. I don't have a rubber band rev, but I don't like to have to redline at WOT either.

Rumblin70SS

Is there any way to tell if I have the Corvette servo? What would be the PN for the TransGo kit? This car is dead stock right now so I don't want to go too radical.

Thanks again for the help.