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My name's not Kevin
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308 Posts
Discussion Starter #1
If you’re looking for a hair, teeth and eyeballs splattered all over the windshield shift. Go buy a shift kit because this won’t do that. But if you want a little firmer shift and more holding power, then keep reading.
I figured that if you had all the proper trans tools i.e. Servo compressor. Then you should already know how to do this mod. So I did it with just basic hand tools. I even tossed in some Redneck tools for you in the South. j/k.
Start by getting all you’re shit together.
1. Floor jack
2. jack stands
3. 10 mm socket (1/4” drive) not for all models
4. 2 flat head screw drivers. 1 large and 1 small
5. couple of rags
6. drip pan. I used a 1-gallon milk jug with the top cut off.
7. Pliers.
8. Plastic screw top to a coke bottle
9. “C” clamp.
DCP_0034.jpg

Start by jacking up and supporting your truck with jack stands. Remember, safety 1st. You can’t enjoy your new mods if you’re dead!
All 700-R4s and 4L60s servos are on the passenger side. Crank your wheel to the left for a little added working room.
On my truck I had a heat shield between the trans and cat bolted to the trans with 2 bolts. Use your 10 mm to remove these bolts then remove the heat shield.
DCP_0011.jpg

Now you should be able to access the servo cover. Using your large screwdriver. Wedge the handle between the servo cover and the trans hump on the floor pan. Grab the blade of the screwdriver and pry the servo cover into the trans. It should go in about a 1/8th of an inch or so. I was able to cram the blade against the exhaust to hold it into place. That way I had 2 hands to work with.
Now you can remove the servo cover snap ring. The trans housing has 2 notches cut into it. The snap ring is exposed in these notches and is easy to get to.
Pull the “O” ring up thru the notch and cut it. Now remove the “O” ring.
Now you can remove the cover.
DCP_0014.jpg

Remove the 4th apply piston. It’s the 1st thing behind the cover.
DCP_0017.jpg

Now comes the tricky part. With my truck I didn’t have enough room to remove the whole servo assy. So I had to remove 1 part at a time. It’s not that hard. But would be a hell of a lot easier if I had the assy. on the bench to take apart.
If you have enough room to remove the whole thing then skip the next few steps. Read them anyway just because I took the time to type them so humor me.
Remove the “E” clip, washer and spring from the apply pin. When removing the “E” clip, cover this thing with your free hand. If it fly’s, Your in trouble. My guess is that your local auto parts store is quite a walk away.
DCP_0016.jpg

With that shit out of the way. You can now remove the inner housing and 2nd apply piston. Inside the 2nd apply piston is your 2nd apply cushion spring and spring retainer they are held in by a snap ring.
DCP_0019.jpg

DCP_0024.jpg

The last part is the Servo return spring. It should just fall out. No big deal.
Now, with everything out. It’s time to remove the piston snap ring. Take your “C” clamp and compress the piston assy. Using a small flat screwdriver. Remove the snap ring.
DCP_0028.jpg

Now is the time to clean your parts.
The servo I received (off E-bay for $13.00 + $4.00 shipping). Came with:
1 servo inner housing
1 2nd apply piston
2 split seals
2 “O” rings. 1 for the inner housing and 1 for the cover.
Old parts on the left. New on the right. Note the larger apply surface (outside ring on the bottom parts)
DCP_0021.jpg

DCP_0022.jpg

OK let’s put this bitch back together. Start with the new 2nd piston, spring and retainer. Here is where the coke top comes in. put it in the piston (not the side the spring goes in).
DCP_0027.jpg

This will protect the hole that the shaft goes thru. Install the spring and cover. Compress it with the “C” clamp and install the snap ring.
DCP_0025.jpg

DCP_0029.jpg

Now install the new split inner and outer seals. Oil the shit out of them with some clean trans fluid.
Now reinstall your apply pin into the piston. Install the return spring and install this whole assy. Back into the trans.
DCP_0030.jpg

Install the pin spring, washer and “E” clip. This step was a pain in the ass. Just take your time. If it starts to piss you off. Walk away and take a break.
Install the inner housing and then 4th apply piston.
Install your new cover “O” ring and install your cover. Press the cover in the same way that you removed it and install the cover snap ring.
Congratulations, You’re done!
 

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GMFS Senior OG Member
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3,511 Posts
Thanks for the very detailed tech article Kevindepot :mexsmoke:
Swapping the servos out will be my next mod i do, but in the mean time I went this route:


 

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My name's not Kevin
Joined
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308 Posts
Discussion Starter #3
Total install time is less than 1/2 hour. I can hardly feel a difference in the way it shifts. But I can feel it holding better. My slip is gone for now.
 

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Registered
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308 Posts
what's the p/n on that b&m kit? how hard is it to install?
 

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Registered
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50 Posts
newbie, chiming in...bear with me, this is the first automatic that I have investigated modding, mostly stick to 6 spds.

What do the servos do, and what benifit do you get from a corvette servo. I read the thread, and I know I can do the mod, but what good will it do me?
 

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resident pyromaniac
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7,498 Posts
it will firm up the first to second gear shift. it will also quicken the shift. the servo helps to prolong the life of the 2nd gear clutchpack that tends to go out in the 4L60e.
 

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patio furniture breaker
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563 Posts
i'm want to order one for my little V6 fullsize. will you even be able to tell with a V6? if it prolongs the life of the tranny, i might just do it.

i've talked to the tranny guy at the dealership. i can get the vette servo for like 20 bucks.
 

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180k & still > 4.8 Rams
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24 Posts
well i just tried installing mine last night and ive had a lot of problems so far. First i coudnt get the servo pin out of the stock housing, i had to carefully use a rubber mallot. It defintely didnt just "fall out." Then after I got it all back together I dont have fourth gear. This is DEFINITELY not a 30 minute job. I spent 3.5 hours and about 3 minor heart attacks on mine already and its still not right!!
 
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