Diving back into the trans again, well, not really. Quick question on corvette servo install

[Dalton Mathison]

Alright well continuing on in my attempt to fix the hang on 1-2 in the TB 5.3l, I've decided my last and final move would be to install the corvette servo. From what I've read, it's easy peasy. Back is feeling better so now I can tackle it myself without anybody else to mess it up but me and myself. My question is, what has to be removed to gain access to the servo? Through my research, I see that some people say you can gain access to it without removing anything. Then I find people who say that the exhaust and crossmember have to be dropped so the trans can slide down a little bit for access to be had. My question is, which is it? For those of you who have done these, any help is appreciated! 03 TB 5.3l V8 by the way.
Thanks so much!

 

[AWD V8]

Well I can't tell you what needs to be removed as I haven't looked under mine for for a long time. I could take a look in the morning and see what I think would need to be moved.

What I can tell you is that once you do get to it, make sure everything around there is clean. Wash and blow away any dirt so when you have it open you don't get crap inside the trans.

Soak the C-clip groove with penetrating fluid because that C-clip will be stuck in there. Their is pressure behind the cover, that and likely some corrosion. You will want to smack that cover a few times to loosen it after you have let it soak. You will have to tap that cover down to release some of the tension on the C-clip so you can dig it out. Once the C-clip is out the cover will not pop out because of the corrosion. The corrosion above the C-clip groove must be removed before that cover will come out. Scrape and wire brush it. Blow it out and tap more lubricate. Tap the cover several times and it may work its way out. I don't know of any other way to pull that cover out of there. The spring behind it will push it out if the bore is free of corrosion.

Once you have the cover off very carefully lift the parts out making a mental note of how the springs are positioned.

The 'vette servo I last did had instructions about the piston rod length. Telling you to ensure it has a certain clearance. Be damned if you will be able to actually measure it and grind it down to fit. I believe I just reused the old push rod as I thought it was close enough. Worked great for me.

I don't know what if anything you need to remove, but the more room you have the easier it will go for you.

 

[Reprise]

If you decide to put the vette servo in, follow @AWD V8 instructions - it was his writeup on the shift kit install I used as my primary guide when I put mine in.

With that said...
- I dont know how you'll have room to get in there w/o dropping the trans down a little bit (2-3 in) - if you look down the passenger side frame rail, you'll see the servo / housing is maybe 1" from the frame rail. To drop it dowm that much, I think removal of the crossmember is required; then you can loosen the rear mount (holding it up w/ a jack / stand, of course!) With care, you can do this without disconnecting the driveshaft from the tailpiece of the 4l60's case, or the bellhousing from the engine.

- However - If you really are putting it in to fix a hang on the 1-2 - what the servo does is hold 1st gear *longer* than stock. You may find afterward that the hang seems worse / more pronounced - not better. YMMV.

 

[Sparky]

FWIW, when cold mine would tend to hang a bit on the 1-2 shift, never did figure out why. I just got used to easing up on the gas a bit at the normal shift point to smooth it out some, and it only did it the first time, maybe second if really cold and/or came to a stop right after and had another 1-2 shift again. Did that for 215k miles!

 

[Dalton Mathison]

Thank you all for your replies. I will definitely be referring back to AWD V8's instructions when I dive into it. After crawling under the truck this morning, I think with removal of the heat shield I can get myself just enough room to get at the servo. I suppose I'll find out if that's the case when the servo comes in the mail and I go under there to do it. I've read that this helps the 1-2 shift greatly and having done just about everything else to fix it, I figured this would be the last try. And even if it doesn't, I know that the servo will help make the transmission last longer. So if it doesn't help the 1-2 lag, at least I know it will be helping the transmission. And I figured for $20, why not. I've always wanted to firm things up a bit anyway, if the TB was used as my family car, I would keep the smooth-shift setup, but as of right now it's normally just me that drives it and I want some firmer shifts.
Thanks for all your replies!

 

[Sparky]

May have to loosen the crossmember to lower the trans a bit, but not remove it.

 

[Dalton Mathison]

May have to loosen the crossmember to lower the trans a bit, but not remove it.

This is good news because I didn't want to have to dive in arm deep to do something as easy as a servo install. Regardless of if I can reach it or not, I may just lower the trans down a bit anyway. As it was said, the more room I have to work, the better the job will go. Waiting for the servo to come in the mail and then I'll get started.

 

[AWD V8]

I will definitely be referring back to AWD V8's instructions when I dive into it.

You're thinking of somebody else, it wasn't me.

 

[Dalton Mathison]

You're thinking of somebody else, it wasn't me.

Oh my goodness, my apologies. I had a nice steamy plate of food on my desk as I typed last night, clearly had my mind focused more on that then I did this. Hadn't eaten all day, was hungry haha.

 

[Reprise]

I'm pretty sure he actually means me - and it's the second time I've confused him with the actual person who made the posts (which, as I write this, I remember that it's @gmcman :: embarrassed::

Must be the length of the handle, or the similarity in their avatars (which, as I see gmcman's, is a pic of an SR-71 'Blackbird' - yeah, that's real similar to the Voy in @AWD V8 's avatar - both are black, but that's about it).

:: runs away screaming::

 

[Bow_Tied]

Can't help with install but I will say the vette servo firms up the 1-2 nicely. It is a bit harsher when cold, but not teeth jarring or anything. If you're driving gently it's hardly noticeable (my wife barely noticed) but it's certainly more definite with some throttle and more confidence inspiring when towing compared to stock, IMHO. Good luck with your project.

 

[Dalton Mathison]

Can't help with install but I will say the vette servo firms up the 1-2 nicely. It is a bit harsher when cold, but not teeth jarring or anything. If you're driving gently it's hardly noticeable (my wife barely noticed) but it's certainly more definite with some throttle and more confidence inspiring when towing compared to stock, IMHO. Good luck with your project.

Really happy to read it. I'm defiantly trying to boost my confidence in this truck, hasn't let me down yet in the 10k miles I've owned it, trying to do everything I can to prevent future transmission issues, although impossible to prevent all of them.
Thanks for the good wishes! Servo should be here Monday morning, pretty excited to get that thing installed.

 

[Dalton Mathison]

Alright SO parts came early this morning. Lowered the transmission, got the servo out, did everything, reinstall the servo. Problem is that I can't seem to get the c-clip for the cover back on. I find it ridiculous that this is the part in this project is what is causing the problems. Any suggestions to get that clip in? Thanks!

 

[Reprise]

Make sure the case area is clean - you want no residuals left from the old servo in the housing. Use a solvent if needed (brake parts cleaner spray works well); allow a few minutes to evaporate before inserting the new servo.

Use TransJel or Vaseline to lube the outer edges of the servo o-rings, and the corresponding areas in the housing. That will help the servo & cover move forward into the case so that you can push it and the cover inward. When you removed the old one, did you wind up having to dig out the outer o-ring in order to be able to remove the servo? Same thing - but in reverse - it's a tight fit, especially w/ a new o-ring.

Once the servo is in, you'll need to pry inward on the center cover a bit, to allow room for the retaining clip to be inserted - put the clip back in, and make sure it seats all the way around. You may need to use a flat screwdriver to move / slide around the circumference of the housing, while guiding the clip into the slot with the tip of the screwdriver. Take care, as you don't want to break the outer portion of the housing that retains the clip - break enough of it off, and the clip won't hold the servo in. Once the entire clip is seated, release the inward pressure on the servo, and you should be set. Might be tricky to do all of this with (only) two hands, under the vehicle.

There are slots at '3' and '6' o'clock of the housing - if you make sure a portion of the clip is visible through at least one of them, it'll be easier to remove the clip, if you ever have to work with the servo again. You can move / spin the clip inside the housing to get the clip surface exposed, if needed (after you have it reseated).

 

[Dalton Mathison]

Make sure the case area is clean - you want no residuals left from the old servo in the housing. Use a solvent if needed (brake parts cleaner spray works well); allow a few minutes to evaporate before inserting the new servo.

Use TransJel or Vaseline to lube the outer edges of the servo o-rings, and the corresponding areas in the housing. That will help the servo & cover move forward into the case so that you can push it and the cover inward. When you removed the old one, did you wind up having to dig out the outer o-ring in order to be able to remove the servo? Same thing - but in reverse - it's a tight fit, especially w/ a new o-ring.

Once the servo is in, you'll need to pry inward on the center cover a bit, to allow room for the retaining clip to be inserted - put the clip back in, and make sure it seats all the way around. You may need to use a flat screwdriver to move / slide around the circumference of the housing, while guiding the clip into the slot with the tip of the screwdriver. Take care, as you don't want to break the outer portion of the housing that retains the clip - break enough of it off, and the clip won't hold the servo in. Once the entire clip is seated, release the inward pressure on the servo, and you should be set. Might be tricky to do all of this with (only) two hands, under the vehicle.

There are slots at '3' and '6' o'clock of the housing - if you make sure a portion of the clip is visible through at least one of them, it'll be easier to remove the clip, if you ever have to work with the servo again. You can move / spin the clip inside the housing to get the clip surface exposed, if needed (after you have it reseated).

Ok well, after a very long day of basically living underneath the truck, got the stupid c-clip back in. Fired it up, took it around the block. It did awesome. Loved the way it shifted, loved everything. 1-2 was fixed. Then, took it on the highway, and I have no overdrive, also it appears it's leaking transmission fluid out the servo cover. Yay :/
Anybody got any ideas as to what I did wrong?

 

[Bow_Tied]

OMG that must be frustrating! Good luck resolving this one; wish I had knowledge to help.

 

[Reprise]

I think if you're able to get that leak stopped (& top off fluid as needed), you'll get 4th again.

Besides the 1-2 shift, the servo also has a function in the 3-4, as well. However, it depends on sufficient fluid pressure to work correctly.

Make sure the O-rings are seated correctly. Also, check the free play with the servo - it should not have more than about 1/8" travel. If you've got twice that or more, then fluid can get past there (and you'll have lower fluid pressure, etc.) Usually, the excess play comes via wear - but since this is a new servo you put in, that shouldn't be an issue.

The fact that this happened right after you swapped the servo points to that as the cause, IMO. A couple of things you can test...

With the vehicle 'overnight cold' (8hr or more), check to see if you get 4th the first time you go through the gears after starting it up. Fluid pressure is higher, when the fluid is cold. You'll likely need to top up before starting it, especially if you've lost a significant amount of fluid during your testing. If you get 4th then, but not as the fluid temp rises, then you know it's a pressure issue.

Try letting up on the gas around the point where you think it would normally shift to 4th. Sometimes the trans will go to 4th, but not be able to hold it (again, a sign of either low pressure). Or, you could have leakage in the 4th accumulator (but you inspected that for wear when you had the VB and separator plate down.) Since the 4th accumulator pin sleeve is a blind hole, that leaves only the tolerance between the sleeve and the pin itself.

Finally, you can try swapping your old servo back in (you'll need a new o-ring or two, as the old ones are worn and / or damaged - and the ones from the new servo may be too large to fit properly on the old one), and see if that stops the issue. If it does, then you'll need to find out the difference between the two of them (assembled correctly? piston out of round? etc.)

Again, my disclaimer - I'm not a professional mechanic - just an owner with a little experience (which can be dangerous in itself.) But I hope you find the cause of the leak and are able to stop it.

 

[Dalton Mathison]

I think if you're able to get that leak stopped (& top off fluid as needed), you'll get 4th again.

Besides the 1-2 shift, the servo also has a function in the 3-4, as well. However, it depends on sufficient fluid pressure to work correctly.

Make sure the O-rings are seated correctly. Also, check the free play with the servo - it should not have more than about 1/8" travel. If you've got twice that or more, then fluid can get past there (and you'll have lower fluid pressure, etc.) Usually, the excess play comes via wear - but since this is a new servo you put in, that shouldn't be an issue.

The fact that this happened right after you swapped the servo points to that as the cause, IMO. A couple of things you can test...

With the vehicle 'overnight cold' (8hr or more), check to see if you get 4th the first time you go through the gears after starting it up. Fluid pressure is higher, when the fluid is cold. You'll likely need to top up before starting it, especially if you've lost a significant amount of fluid during your testing. If you get 4th then, but not as the fluid temp rises, then you know it's a pressure issue.

Try letting up on the gas around the point where you think it would normally shift to 4th. Sometimes the trans will go to 4th, but not be able to hold it (again, a sign of either low pressure). Or, you could have leakage in the 4th accumulator (but you inspected that for wear when you had the VB and separator plate down.) Since the 4th accumulator pin sleeve is a blind hole, that leaves only the tolerance between the sleeve and the pin itself.

Finally, you can try swapping your old servo back in (you'll need a new o-ring or two, as the old ones are worn and / or damaged - and the ones from the new servo may be too large to fit properly on the old one), and see if that stops the issue. If it does, then you'll need to find out the difference between the two of them (assembled correctly? piston out of round? etc.)

Again, my disclaimer - I'm not a professional mechanic - just an owner with a little experience (which can be dangerous in itself.) But I hope you find the cause of the leak and are able to stop it.

Thanks for all your help, I guess when I finally got the stupid c-clip installed, I didn't do it well enough because once I fired the truck up and was driving down the road plumes of smoke were following me--which I found out when I took it back apart today that the cover for the servo was sitting half-open. I took the cover off, checked everything over, and reinstalled it (the right way this time) filled the truck up with fluid, and it's been amazing ever since. 1-2 hang and rough shift are gone, it shifts much better then it did, not sloppy anymore. Very pleased with it, and I think it was worth the work
Thanks everyone for your replies!