24UGTOinFL

Is there any change in performance regarding the servo pin length? Sonnax says .075"-.125". Does it just need to be in somewhere in the range or does it affect some shift property depending on where you are in the range?

Also, there is a note in the Sonnax instructions about not re-using a flat-sided retaining ring on MY2004 to mid-April 2004 transmissions. I have a 2004 Pontiac GTO so I would think that'd be me. Does anyone know what part I need to buy?

Finally, I also ordered a .490 boost valve because I thought I read that transmission removal/disasembly wasn't required, only filter removal. Admittedly, I'm not at all familiar with the guts of this transmsission (had the pan off once to change filter) but looking at the Sonnax instructions seems like I may have missed something. Is it, indeed, possible to install without taking it all apart? If installation is about like the servos, I can do it. Any more and it'll have to wait for a different day.

I appreciate any guidance.

performabuilt

iTrader: (25)

The pin length is used to determine the band clearance and is selective , You want min clearance yet still be able to turn the drive shaft in both direction by hand with the car in neutral not running is the simplest way without removing the pan .

Yes you can install the boost valve without pulling the trans though its a bit of a pain under the car, Its simple enough , When your under there you will see .

24UGTOinFL

Can this be determined before putting all the o-rings on? Or, do you have to put it all together and check? Should the driveshaft turn both ways when NOT pushing in on the servo (as when measuring clearance)? I presume so but just want to verify.

Trans will be out. Just wouldn't be able to pull the pump or valve body out or anything similarly complicated. Needs to be quick and easy, which is what I thought I read.

performabuilt

iTrader: (25)

yes that would be turning without the servo compressed and yes without the orings

24UGTOinFL

Excellent. Thank you so much for the information.

Have you heard or seen this issue with the retaining ring? Is it something I need to be concerned with?

performabuilt

iTrader: (25)

I have not run into it but if they say not to use the one with the flat then i would aquire a round one . Local trans shop should be able to help you

24UGTOinFL

For future searchers:

Bulletin No.: 04-07-30-025A
Date: July 27, 2004

Subject:
Transmission Fluid Leak, Inoperative 2nd/3rd/4th Gears, No Movement, Case Cracked or Broken at 2-4 Servo (Repair Transmission and Install New Retaining Ring)

Models:
2004 Chevrolet Corvette
2004 Pontiac GTO
2004 Light Duty Trucks

with 4L60-E and 4L65-E Automatic Transmission (RPOs M30 or M32)

Condition
Some customers may comment on a transmission leak, inoperative 2nd/4th gear, slipping 3rd/4th gear or no movement due to excess fluid loss.

Cause
This condition normally occurs at low mileage, usually under 1,600 km (1,000 mi), and investigation may show that the servo cover is loose or that the transmission case is cracked or broken at the servo bore.

This condition may be caused by a servo cover retaining ring that did not retain the servo cover.

The servo retaining ring design was changed for the 2004 MY from round wire to wire with two flat faces.

In mid-April, 2004, the retaining ring design did revert back to a round design in production.

It is possible that the transmission case may crack at the servo cover area due to the retaining ring being incorrectly seated.

Correction

Important:
^ In mid-April, 2004, the retaining ring design did revert back to a round design in production.

^ If the transmission fluid level has lowered due to loss of fluid, it is possible that damaged 3/4 clutches will result.

^ A cracked or broken case may usually be repaired at a significantly lower cost than transmission assembly replacement by replacing the case and any damaged clutches or bands.

Revised retaining ring is GM Part # 24232065. About $8 locally. I'm well out of the problem mileage range but got a new one anyway.

Thanks again for the help.

24UGTOinFL

The springs that are inside the intermediate servo: Are they under a lot of compression? Anything to worry about from a safety standpoint when taking the snap ring off?

tptransmission

There is only the return spring pressure when the engine is not running. You will probably have to give it a little assistance to get it out

24UGTOinFL

Hopefully, the last question about this.

Assembly lube: Is ATF acceptable?

performabuilt

iTrader: (25)

actually petrolium jelly vaseline works very well

24UGTOinFL

I just wanted to thank everyone again for the help and information. I was able to install everything without too much problem. The only stumbles were that the overdrive servo was a tight fit once the o-rings were installed and I struggled getting the boost valve out and in. The boost valve snap ring was almost out of reach of the short jaw pliers I had and I had to use a punch to unload the boost valve so that it would constrict. Then, I had to use needle-nose pliers to pull the boost valve out. I guess I was under the impression it would fall out. When going back in, I ended up needing to tap it ever so slightly to get it past the snap ring groove. Similarly, the overdrive servo just needed some very slight persuasion with a plastic-faced hammer to get it in far enough to install the snap ring. So far, I am VERY happy with the way it works. Couldn't (wouldn't) have done without the help. So, thanks again.