Discussion: Shift Kit How-To/Write Up


Just another guy
Mar 8, 2012
Sanger, TX
See post #2 for disclaimer and credit.


For all you guys wanting or wondering about how and what it takes to upgrade your 4L60E and 4L65E transmissions, this will give you an idea of what you will be getting into. Personally if you are mechanically inclined and have basic hand tools YOU CAN DO THIS. Transmissions can be intimidating due to all the small parts and the amount of parts internally. But if you do your research, read carefully, take your time, keep things organized, clean, and double check your work it can be accomplished.
What is the point of a shift kit/servo upgrade?

The best way to describe this (at least that I can describe) is to use the word "overlap". On a bone stock transmission, overlap is referring to the softness between upshifts (1-2, 2-3, 3-4) and also downshifts. For example, when you ride your brakes while driving the pads will fail and wear a lot sooner and generate heat right? Take that and convert it over to what happens in a transmission. When your transmission is shifting into a higher gear, the lower gear has not fully released all the way. So for the short time the transmission is in two gears at once they are essentially "slipping" as one or the other has not fully engaged. Hence the saying "overlap". This is also happens on a downshift as well. This generates heat and removes clutch and band lining at a greater rate. As well as glazing/polishing the clutches, steels, drums, band, etc. When you install a "shift kit" and servo upgrade you are positively modifying the valve bodies ability to apply and/or direct fluid to the clutch or band apply circuit. This firms or quickens shifts by releasing and applying circuits more efficiently and reducing "overlap". Now for those who ask "will my transmission hold up by doing this for so and so mods / horsepower?" There is not answer to that. Again this is a process to help the longevity of the stock 60E due to the issues above. This will not correct breaking of input/output shafts, pinion failure, reaction sun shell breaking, etc. With all that happens inside a transmission it’s hard to tell what’s going to break first with all the variables for a failure.

What parts to use.

There are a good handful of parts and pieces out there to choose from when it comes to this upgrade. The parts listed below are parts that I have used and have had good experience with. So I will suggest these to you. I am not at all saying the other parts on the market are inferior such as Trans-Go as many run their product with good luck, but I have not heard anything as far as negative feedback with these. First off, you can easily find 90% of these parts on this website http://www.transmissioncenter.net/4l60e.htm You might have to hunt around a little on the site for the parts but you will find them. They should be in descending order through the web page. I will have the part number first, part name, and a little description as to what it is and why to use it.

#2 – 4L60E Corvette 2nd Intermediate Servo : This is the servo that comes in high performance Corvettes and Camaros. It has a greater fluid apply surface area which in turn will apply or "grab" the 2-4 band more efficiently. Other options are the Superior and Sonnax 2nds. I have ran both the Corvette and Superior 2nd in different transmissions and in my opinion one isn’t any better than the other as far as applying. They both felt the same. There is thought you will get a better 2-3 shift from the Superior and Sonnax, but for the money the Corvette is by far the best bang for the buck.

#3 – 4L60E high performance overdrive 4th servo : Made by Sonnax and has a 40% more holding power (fluid apply area) than the factory 4th. This will not remedy the weak 3-4 clutch pack 60E's are known to have but will obviously help (which is the point of this whole write-up)

#27 – 4L60E / 4L65E oversize .490" pressure boost valve and sleeve. The stock size is .470" and the larger diameter valve will yield a 10% to 15% higher line pressure. Instead of drilling the factory sleeve with the drill bit supplied in the shift kit, you will just replace factory ones with these.

#37AP2 – 4L60E Billet Forward Accumulator. This piston goes in the valve body and cushions the shock when shifting from reverse to drive. Very common for the factory plastic piston to wear or crack. This will result in fluid loss, delayed engagement, slipping, burned clutches and/or band. This is a very cheap part and should most defiantly be replaced. You will replace a spring or springs in this bore so replace this!

#37AP – 4L60E 3-4 factory accumulator piston. These are aluminum from the factory but have a tendency for the center hole to wear resulting in loss of pressure. Again, you will have this out so replace this!

#37AP3 – 4L60E 1-2 factory accumulator piston. Same issue as above. Replace due to having out.

#K4L60E-L – Superior Shift Kit fits 1998 and up. Self explanatory. As stated above, I am suggesting this kit due to the fact of the positive feedback I have had from it, and others as well.

You will need to get this from your local GM Dealer.
P/N 24221349 - GM Updated Valve Body Spacer Plate and Gasket set. Reason behind replacing this is the factory separator plates had an issue with the checkballs deeply wearing into the plate and sometimes all the way through. My factory transmission had shy over 30k miles on it, and one of the checkballs by the 1-2 accumulator housing had worn a pretty good groove in the plate already. Don’t remember the cost, but it wasn’t bad.

Fluid Filter and Pan Gasket Kit
You will need a fluid filter and pan gasket kit. You can either get this from your GM dealer while you are there or your local O'Reilly, Napa, ect.

For fluid brand, that is up to you. To be honest, O'Reilly ATF is perfectly fine and is what I use and many others as well. If you feel you need to have a brand name such as Valvoline go for it. Pick up a case, you will have extra but you can take the extra back or keep it for future instances. Always good to have ATF on the shelf.

Fluid Friction Modifier

While you are at your local O'Reillys, pick up a bottle of Platinum Lube Guard transmission fluid friction modifier. What is this you say? In a nut shell, all ATF has some sort of friction modifier in them. They are chemical additives in the fluid that effect how the transmission feels when it shifts gears. Specs vary to one make or model to the other, hence the variety of ATF's out there. As miles add up, or "abuse" is given to the trans heat and consistent shearing of the internal parts break down ATF. When this happens one of the first things that goes is the friction modifiers in the fluid. When this happens shifts may become rough and jerky. Ever heard of someone saying when they changed transmission fluid and filter it shifts so much better? Wala. When filling your transmission up with new fluid, pour a bottle of this in with it.

A few other odds and ends you should have when doing this. If you have access to Vaseline you will need a tiny bit to keep the checkballs in place during re installation. Also 3-4 cans of brake clean.

1/4 ratchet
3/8 ratchet
Various metric sockets and wrenches
Flat blade screwdriver
1/4 or 3 /8 torque wrench
Various picks if applicable
Handle to pry servo cover with
Great info, we should be able to quote the whole thing, and cite it with the original link
How – To Write Up

I don’t have many pictures with this but it should be self explanatory in its own. I have provided the instructions from the shift kit itself with a few notes on them to aid in the installation. You can install this upgrade in two different ways. One with the transmission in the truck or with the transmission out on the bench. Usually if its on the bench you are installing a converter as well. But this can be accomplished with the transmission still in the truck.
A little tip if doing it in the truck. If you have the time, get the fluid drained the night before and let the excess drip overnight. This will be much easier than having trans fluid dripping down your arms or in your eyes. If you do this, be smart about it. You don’t want to leave the transmission open to foreign elements such as excessive dust and debris.

• Secure truck on level ground with proper jackstands or safe lifting mechanism. (if you have access to a lift, then you are the man)
• Remove exhaust. All you need to remove is the mid pipe from the left (drivers) bank coming across to the right. (you pacesetter guys that weld your collectors, you will need to figure something out!)
• On the left side of the transmission you will find your shift linkage. You can take a flat screwdriver and pop the cable from the linkage rod. You will then see a cable bracket that’s bolted to the trans case. Don’t try to take this bracket off. There is a metal "U" clip that holds the cable in the bracket. Once you pry out the clip, depress the tabs on the cable and shimmy out the cable from the bracket. Set aside.
• Most likely you guys will be doing this on the floor so the front of the truck will be higher than the rear making the fluid in the pan slosh to the rear of the pan. Loosen the bolts to where fluid will start dripping out of the rear of the pan, then slowly loosen the others. When a steady flow of fluid stops coming out you can shimmy the pan from the cable bracket and set aside. You kind of have drop the right side of the pan down first then take it will come free from the bracket.(you guys that already have a drain plug in your pan, you just made your fluid draining experience easier and less messy)
• Now you will see your fluid filter. To loosen kind of move side to side till you free it up a bit. Then gently remove.
• Next is the manual detent spring by the rooster comb. Remove
• Next is to disconnect all electrical connections. There should be 6-7 connectors. Then last there is two bolts holding the TCC (torque converter clutch) solenoid in place. This is located at the front of the valve body, follow the wiring and you will find it.
NOTE: Do not try to remove the entire harness from the case. There is a special way to get the connector out of the case and there is no need to do it. So just tie it up out of your way.
• Next should be your transmission fluid pressure manual valve position switch. Kind of looks like a circuit board by the rooster comb. Should be 5 bolts holding it on, 3 big and 2 small. REMEMBER WHERE THE BOLTS GO. When reinstalling if you get a big bolt in the smaller hole and go to torque, you will bottom out the bolt and snap it off in the case!
• Next is the fluid indicator stop bracket. This is located on the opposite side of the rooster comb in the front corner.
• Next is to loosen the valve body. Again it is crucial you remember what bolts go where as there are different size bolts for the valve body. Once you loosen the VB, you will have to take off the link to the manual valve. (again by the rooster comb). NOTE: Be careful when pulling down the VB as there are check balls that will come down with it that is between the VB and case.
• Next is to remove the 1-2 accumulator housing. This is located in the rear corner of the case. There are 2 small bolts and 1 large. Set aside
• Next is the spacer support plate. Should be 3 bolts same size
• Remove gaskets and spacer plate.
• Next is the servo assembly. There is a round snap ring that holds the assembly in the case. Doing this in the truck can be kind of tricky. You will need to depress the servo into the transmission, then pry out the metal snap ring. Again, this could be difficult while in the truck. If you are doing this on the bench, secure the trans on the table, take the bottom end of a hammer handle or any type of handle and depress the servo in the case then pry out the snap ring.
• Once you get the snap ring out, there will be a black (if I remember right is factory and blue is aftermarket) o-ring for the servo cover. You will have this o-ring in your servo kit so you can pry some of the o-ring out then cut it. Remove and the servo assembly should pull right out. NOTE: keep the assembly in tact until you go to swap the 2nd and 4th apply servos later. That way you don’t get confused on what goes where.

Here are the instructions I scanned. Hopefully they are big enough to read. And yes, my hand writing is horrible LOL.



NOTE: when performing step 8, make sure when you are installing the plug, not to install with something that will puncture through the plug. Use something that will cover the surface area of the plug and tap it in very slow. Make sure its in there too, you will know when it is seated.

NOTE: after the servo installation, double and triple check your round snap ring that hold the assembly in the case. It is common for guys to miss this and not have the ring fully seated in the case. Trust me, you don’t want to have this happen!

NOTE: if you have had your truck tuned by one of the tuners on the site (Wheatley, Blackbear, Zippy) or had someone local. Have them clear your adaptive shifts in your tune and adjust the torque management. Remember, you want some torque management set in still and do not want to clear it 100% especially for the 2-3 shift. Having a transmission that breaks your neck when shifting isn’t necessary. You will break hard parts in a hurry. Good clean, crisp shifts is what we are after here.

Now that you have everything apart you can start the assembly process. Get our your instructions start from the top. I have attached the instructions with a few little notes to go along with it. Tighten all VB bolts inside pan to roughly 8-10 ft lbs. Again be sure you get your bolts in the right holes!! When re-filling transmission with fluid, make sure truck is on level ground. Start by pouring in 4-5 quarts then check. Remember you still have fluid in the torque converter (if you did this in the truck) When you see fluid on the dipstick start the truck and get to operating temperature. While truck is warming up, check for any obvious leaks. Set the parking brake and put the transmission ins neutral position. Then fill as needed.. Then put the truck in drive and make sure it engages all gears (D,3,2,1) and reverse. Road test. Monitor for transmission engaging all gears correctly and downshifts. Recheck for leaks after test.


This might seem like a tall task to handle but it really isn’t. Again if you are mechanically inclined you can do it. The best thing you can do is stay clean. Stay organized. (OCD is not a bad thing in this case). Double check your work, if anything triple check if it makes you feel better.


I AM NOT THE ORIGINAL WRITER OF THIS HOW-TO. I OBTAINED PERMISSION TO RE-POST FROM THE ORIGINAL AUTHOR. Here is the original link: http://www.silveradoss.com/forums/topic/67343-shift-kit-w-servo-how-to-write-up/
The Corvette Servo thread

Props to xlcooplx!

Yes, the amount of reoccuring threads inquiring about the additon of a corvette servo has lead me to creating a master thread here. I believe there have been 6 threads regarding this just in the last few weeks.

In this thread I am going to attempt to answer more of the questions related to the servo swap instead of writing another how-to on it as both KevinDepot and FatKidKustomz have already completed two thorough install how-to's. Okay, here we go.

First of all, the addition of a Corvette servo can be done to all 700-R4/4L60e transmissions. 1982 introduced the 700-R4 trans to the world. The trans remained the same until 1993, although in 93 it was renamed the 4L60. In 1994, GM rear-wheel drive vehicles got the new electronic controlled 4L60-e. The 4L60e has remained in the 1/2 ton series truck until present time. If you have a 4speed auto in your 1500 series, 94 and newer, then it is a 4L60-e, so YES, the vette servo WILL work in it. That's all 700-R4's 82+Present and 4L60-e's 94-Present (2008).

The servo is located inside of the servo housing that is located on the passenger side of the transmission. The servo swap can be performed with the transmission in the truck and also without dropping the transmission pan. Depending on the exhaust setup, you may have to disassemble the servo assembly in the housing. See the How-To write-ups for more info.

The purpose of the vette servo mod is to allow the transmission to shift more quickly and efficiently from first to second gear. From the factory, the truck 4L60e's have a smaller servo. The servo is used to apply the 2-4 band in the transmission. Upgrading to the vette servo gives the trans more "holding" power and thus yields a quicker/firmer shift. Adding a vette servo has also seemed to cause some folks 1-2 slipping to cease. Below is a photo of the stock truck servo (left) and vette servo (right).

The easiest place to get a servo is from Oregon Performance Transmission off of ebay. I belive they're $17.95 shipped. Their username on ebay is oregonperformancetransmission. You can also try searching using phrases such as "CORVETTE SERVO, 700R4 4L60, 4L60-E." Often, you will see the servos being sold with a longer pin. You do NOT need the pin. I've read where it only offers 1/32" of end play for the cover so it makes no difference at all. Below are the links to the how-to's.

The biggest difficulty that you may run into while installing the servo is getting the servo cover back on with the snap ring seated properly. Take your time, it will go on. If you do not get it seated properly, you will cause the servo assembly to jam inside the housing and worst case, you will ruin the housing. Below are the how to articles that provide more in depth installation instructions.

I'm sure I've missed something. Everyone feel free to add/correct anything that I have may missed. Maybe we can put an end to these threads...

Edit: Thanks to Eric for this:shake:
Last edited by a moderator:
My truck shifts really hard at about 1/2-3/4 throttle from first to second. Is this something that the vetted servo could help eliminate?

Sent from my DROIDX using Xparent Red Tapatalk
My truck shifts really hard at about 1/2-3/4 throttle from first to second. Is this something that the vetted servo could help eliminate?

Sent from my DROIDX using Xparent Red Tapatalk

Doubtful. I've found that my crew cab bangs from 1st to 2nd around 1/4 throttle. I believe it's mostly in the factory tune calibration more than anything. I need to break out my EFILive and see about changing the parameters. If anything, the vette servo makes the shift quicker, but not necessarily any less harsh.
Last edited:
If anything it will become a littler firmer,i dont see how anyone could think a stock truck/stock tune could have a harsh shift
I wouldnt set it up with a shift kit, i srs
Sams sonnax/shift kit is wild
My fairbanks and OD is wild also im scared to put the boost valve they sent me in which suppostly it helps big time but i dont need any more
Most ppl set the vette/transgo up
If you get on pt.net they say the fairbanks isnt the best idea for a stock trans, performabuilt doesnt use the fairbanks until lvl 3 if that says anything.
I got this from Rhino79 over at PerformanceTrucks.net Forums - Powered by vBulletin

original thread: http://www.performancetrucks.net/fo...22/corvette-servo-install-w-alot-pics-476223/


Well I figured while I'm waiting on the converter to come back from Yank, I would go ahead and install the vette servo. I see people have been going to GMFullsize to view their sticky and thought we needed one of our own over here! I took alot of pics, and here we go....

Parts Needed:
Vette Servo Kit (about 17 bucks from oregon perfromance)

Tools needed:
Small flat blade screwdriver
Medium sized pry bar (to press in the servo cover)
C-clamp (or something to compress with)


On the passenger side of the transmission locate the round servo cover. I was able to insert my pry bar between the y-pipe and get the end on the center of the cover.


Push the cover in until it stops and remove the locking ring, it's just a round clip shaped like a "c" that locks just inside the lip of the transmission case around the cover. Use a small flat blade or pick to remove it.


You can now release the pressure from the servo cover. Pull the cover out until it stops, pliers may be needed to grip the center snout of the cover to pull it out. Use your small flat blade or pick to pull the blue o-ring out of the slot enough to cut it and remove it. This will make the cover removal much easier.



You can now completely remove the servo cover and set aside. At this point you can see the 4th apply piston. Slide it off the pin ***pay attention to the way it is turned***. Set it aside with the servo cover. Both of these components will not be needed until the reassembly.



Now you can slide the entire servo assembly out.



Now we can start the disassembly of the pin/2nd apply servo setup. There is a "E" clip located on the end of the shaft with a washer and the servo apply spring beneath it. Using one hand, compress the washer/spring and with the other, use your small flat blade screwdriver to remove the clip, the washer, and spring. Set them aside.




Now we can disassemble the servo piston housing, the 2nd apply piston, and the pin.


On the back side of the 2nd apply piston, there is a circlip, spring, and cover that needs to be disassembled. Use your c-clamp (or equivilant...my c-clamps were at work). Compress the cover and remove the circlip. Now you can remove the cover and spring from the original 2nd apply piston.



In the next photo, the original servo piston and housing are on the left. The corvette servo piston and housing are on the right.


Last edited:
Now that we are completely disassembled, lets clean up the parts and reassemble. In the next photo we are putting the cushion spring and cover back into the vette 2nd apply piston. MAKE SURE THE CIRCLIP IS FULLY SEATED IN IT'S GROOVE. You will need your c-clamp or equivilant device to compress the spring enough to put the circlip in.




Slide the pin back in the 2nd apply piston, install the NEW oil seal ring on the small end of the 2nd apply piston. Make sure to lube all the o-rings with a dab of transmission fluid when assembling. On the 2nd apply piston, these rings are "cut" . Make sure they are squeezed together fully, it should look as if it isn't cut when its installed properly. Once you have the oil seal ring on the small end of the 2nd apply piston, slide the 2nd apply housing over the 2nd apply piston making sure the housing is turned the right way. You can also install the Brown O-ring on the servo housing and the Oil seal ring on the big end of the 2nd apply piston.




Now install the small spring, washer and "e" clip. MAKE SURE THE CLIP IS FULLY SEATED IN THE GROVE!



Here is the assembly, ready to go back in. The blue o-ring is for the servo cover.


We are ready to reinstall in the transmission now. In this photo you will see a small spring (servo return spring). IT DIDN'T COME OUT WHEN I REMOVED THE SERVO UPON DISASSEMBLY, IN THE EVENT THAT IT DID, MAKE SURE YOU RE-INSTALL IT. This photo will show you the placement. it has a snout it locates itself on.


Ensure the edge of the case where the cover goes is clean, you do not want to damage an o-ring or drag dirt in when you slide the assembly back in.

With that being said, slide the assembly in. Once it is fully in, reinstall the 4th apply piston that was removed earlier. NOTE: MAKE SURE THAT YOU HAVE THE THE 4th APPLY PISTON TURNED THE CORRECT WAY.



should help

Now, install the new o-ring on the servo cover. Be sure to put some transmission fluid on it to ease the installation of the cover and prevent damage to the o-ring. Install the cover by hand, it will push in fairly easy. Now you can use your prybar to fully compress the cover into the case. Install the c-clip and MAKE SURE IT IS SEATED PROPERLY.



I noticed A LOT of difference in the 1-2 shift. Enough I had to remove some of the line pressure I added during tuning, I put it back to stock. It is so much more crisp and positive. No more dragging into 2nd gear at WOT. I have all my TQ MGT removed and it bumps nicely.

I hope that this helps some people. By far the best 20 bucks you can spend on your transmission and it will help save the trans for sure

Should help
First of all, thanks for refrencing my how-to on your site. Hopefully it helps many of you with your trans questions and possibly the ones that questioned themself if they could perform this task or not. Please feel free to email me with any questions you might have regarding this. bmurta@midwaytrucks.com

My truck shifts really hard at about 1/2-3/4 throttle from first to second. Is this something that the vetted servo could help eliminate?
Sent from my DROIDX using Xparent Red Tapatalk

The vette servo will not eliminate this. Did this "hard shift" all the sudden start or has progressivly gotten more firm? Something to try is to clear the adaptive shift in the PCM. This means the PCM will adapt to driving habbits of the driver. Take for example, somone that gets into an 80 year old grandma car, it will shift nice, smooth, and soft. Get into a car with an 18 year old and the trans will shift firmer. This is why I asked if it progressivly got firmer.

billet servo is the way to go.
vette servo was a waist for me IMO. I could have just boosted line pressure for that.

Boosting line pressure is not something to practice. As stated in the thread, the vette servo yields a larger apply area which aids in the apply and release of the 2-4 band. This effects strictly the apply and release of the 2-4 band. Increasing line pressure to achieve this effects the entire hydraulics of the trans. Paying someone 50 bucks to install one is a waist as it can be installed with very basic hand tools.

Also, when comparing the billet 2nd to the covette 2nd. I have ran both and I have also ran two different brands of billets. To me paying 70 bucks for a billet and 15 or so for the vette when they honestly perform the same is a no brainer. I have heard guys say the billet 2nds "hit" harder. Again, we dont need rock crushing 1-2 shifts. This is how you break stuff. Firm and quick apply and release is all we want here.
Last edited:
What is your opinion on torque management removal? I won't be towing anything at all, and if I ever do haul anything, it won't be more than 3-400 lbs. Black Bear Performance is coming into town, and I was thinking about having 50% TM removed on standard, and 100% on sport mode\tow-haul button.