4L60E Corvette Servo Install; Walkthrough with pictures and details!!
 

I recently installed a Corvette Servo in my transmission, and thought I'd take the time to make a walkthrough, since I know how it can be nerve-wracking digging into your trans. Before you begin, I just want to reassure you, its not very hard to do!! It took me about an hour, and thats with taking my time to clean my hands so I could take pictures.

Now, your probably thinking "what the hell would I need this for?!" Well, basically, all this does is gives you a firmer 1st-2nd, 2nd-3rd gear shift, and gives you 50% better holding power in second gear. It uses a bigger piston to apply against the band, which in turn holds the drum alot better. Its not going to chirp the tires every gear like a shift kit would, but it will give you an improvement in shift quality, which is good for towing and such.


For starters, your gonna need your corvette servo, I got mine off of ebay from a company called CT Powertrain, it costed a whopping $14 bucks.

https://blazerforum.com/forum/attach...ine=1391480097

http://www.ebay.com/itm/700-700R4-4L...e1e231&vxp=mtr

For tools, all you need is some picks, a couple flathead screwdrivers, channel locks, a big c-clamp, some brake clean, and a quart of FRESH trans fluid.

BE SURE TO CLEAN ALL PARTS WITH BREAK CLEAN AND A LINT FREE TOWEL!!!

The valvebody in the trans has very tight tolerances, and even a small piece of lint can screw up its operation, so everything has to be PERFECTLY CLEAN!! I used paper towels to wipe everything down, and I suggest you do the same!!

First, jack up the passenger side of the vehicle, get under, and this is what your looking for.

https://blazerforum.com/forum/attach...ine=1391480097

Now get your big screwdriver, and pry that cover in. I went against the torsion bar on my blazer, and that worked great! Now look closely, see the notch? Theres a big c clip you need to pull. I got that out with a smaller flathead. Now you can pull the cover off! Chances are, its not just gonna pop out, so use your channel locks on that little circle part, and rotate it back and forth until it walks out.

https://blazerforum.com/forum/attach...ine=1391480097

After you get that off, this is what your gonna be looking at. This is the 4th gear apply piston.

https://blazerforum.com/forum/attach...ine=1391480097

Now pull it out! It just slides right off

https://blazerforum.com/forum/attach...ine=1391480097

What your looking at now

https://blazerforum.com/forum/attach...ine=1391480097

Out of the trans!

https://blazerforum.com/forum/attach...ine=1391480097

Now pull the rest of the servo

https://blazerforum.com/forum/attach...ine=1391480097

Then this spring. Don't loose this!!

https://blazerforum.com/forum/attach...ine=1391480097

Now that you have the assembly out, its time to swap some parts. First pull this e-clip, careful because it has a tendency to fly across the garage and go missing. Save yourself the headache and cover it with your hand while you pull it. This is where your 90 degree pick tool comes in handy!!

https://blazerforum.com/forum/attach...ine=1391480097

Now you should have these parts lying out on your workbench

https://blazerforum.com/forum/attach...ine=1391480097

Next, pull the piston rod out. This is what physically touches the band

https://blazerforum.com/forum/attach...ine=1391480097

Compress the spring with your c-clamp

https://blazerforum.com/forum/attach...ine=1391480097

Pull the snap ring

https://blazerforum.com/forum/attach...ine=1391480097

Now pull this cover off, and the big spring. You'll be transfering these to the new servo

https://blazerforum.com/forum/attach...ine=1391480097

https://blazerforum.com/forum/attach...ine=1391480097

Comparing old parts (left) to new (right)

https://blazerforum.com/forum/attach...ine=1391480097

The new servo, install your new teflon rings into the grooves

https://blazerforum.com/forum/attach...ine=1391480097

https://blazerforum.com/forum/attach...ine=1391480097

https://blazerforum.com/forum/attach...ine=1391480097

Slide the piston back in

https://blazerforum.com/forum/attach...ine=1391480097

Install the spring

https://blazerforum.com/forum/attach...ine=1391480097

Washer

https://blazerforum.com/forum/attach...ine=1391480097

And finally the e-clip

https://blazerforum.com/forum/attach...ine=1391480097

Now for re-installation! First install the spring...

https://blazerforum.com/forum/attach...ine=1391480097

Then the second gear servo assembly

https://blazerforum.com/forum/attach...ine=1391480097

Then this thing (don't know the name of it) MAKE SURE the notches on it point OUTWARDS!!

https://blazerforum.com/forum/attach...ine=1391480097

Then the 4th gear apply piston. Make sure you install it the right way, or you'll have to pop the cover off and turn it around to get overdrive back

https://blazerforum.com/forum/attach...ine=1391480097

Then the servo cover!! Be sure to throw your new o-ring on, and lube everything with trans fluid!

https://blazerforum.com/forum/attach...ine=1391480097

Now, all you have to do is pop the servo cover on, throw on the snap ring then take it for a test drive. If it doesn't leak on the first startup, then you should be fine! Now take it for a test drive and enjoy your nice crisp shifts!!

Good walk thru! If you had to do it again would you go straight to the corvette or sonething in between, a little less aggressive? Also do you know how to fool the electronic pressure regulator with a resistor?

Very interesting, nice write up!

Thanks!! I think I would recommend using the corvette servo, because its a tried and true GM designed part, and I don't feel its very aggressive to be honest. I'd reccomend it to someone who would like to improve the mushy shift from the factory, without going overboard with a shift kit. And no, I've never heard of doing that to be honest. If you'd like to shed some light on that feel free!!

Thanks!! I feel like it was well worth the effort to take the time so others can feel confident doing this mod!

The thread is kind of old but I think it is THE $4.00 TRANS MOD or something like that. It also speaks about too much pressure. My trans parts man suggested that the vette servo is too much and the stock one is too cush. I think he said there were 4 stock sizes

I read last week that you were waiting on your vette servo... thanks so much for posting this walk through, if I don't use it this weekend... well, that means I found out it's not my servo- but I'm sure it will come in handy for someone!

Did this on my servo, not to aggressive at all. Tighter shift, less slippage, less wear. Worth 14.00 and an hours work

I'll have to look that up. I've never seen any different sizes, we did one on my buddies 02 Z71 Silverado, and it was the same part as mine.

Glad I could help!! Hope it goes well for you, I'm really enjoying mine so far. I've put about 250 miles on it so far and haven't had an issue yet!

That's what I said!! I can almost chirp second when I get on it! The back end just squats when it shifts under WOT now..

This is looking like an easy project. It affects 1-2 shift only or all shifts?

I believe it effects all but I notice it most on 1-2

Its supposed to help with 1-2 and 2-3. For 4th gear you can get a billet servo which will help you hold overdrive longer, which is better for highway driving. It also keeps your torque converter at full engagement when the PCM kicks it on, instead of the sloppy, half engagement that it has from the factory at times. I would have already done that if it wasn't a hundred bucks, lol

Thanks I'm going to do this asap.

Thank you for this write up! I was about to drop the trans to get this done, since it seems most of the full sized truck guys think that's mandatory for the little Blazer. A buddy at work said the same thing. I read other write ups but none as reassuring as this for the small trucks.

Have my parts ordered and going to get this done soon. I know it's not an immentent doom situation, but the wife who normally drives it is constantly complaining about how she feels it's going to leave her stranded or something because it shifts a tad lazy.

I'll post back with results. Thanks again!

Thanks, I got my vette servo a few days ago. Will be putting it in today after seeing your how to post.

The trans in my 1996 Tahoe was rebuilt right before I bought it, and I hated the mushy shifts. My friends 96 chevy truck shifts the same way. I put the Corvette servo in yesterday, and now I love it. The pictures you took were very good, and made the job very easy (about an hour) Thanks.

which position do the scarf(cut) O-rings go?