Corvette Servo on Denali?

[PNWMuseumman]

Good morning all!

I know I have seen a lot about adding the corvette servo to the tahoe and it being awesome. That was my plan until it bit the dust. Now that I have my wifes 02 Denali instead though, I have been mapping out the mods I want...

Has anyone done the corvette servo on the denali? I tried to look and see if it is a thing, but couldn't really find much that wasn't about doing it on tahoes.

Many thanks!
Chris

 

[HiHoeSilver]

Good morning all!

I know I have seen a lot about adding the corvette servo to the tahoe and it being awesome. That was my plan until it bit the dust. Now that I have my wifes 02 Denali instead though, I have been mapping out the mods I want...

Has anyone done the corvette servo on the denali? I tried to look and see if it is a thing, but couldn't really find much that wasn't about doing it on tahoes.

Many thanks!
Chris

I don't have the first hand experience you're looking for, but your Denali should have a 4l65, so the servo is the same as the 4l60. The only difference is the awd system, but I don't see why that would mean you couldn't / wouldn't do it.

I've had thoughts of doing it to my Denali as well, so I'm curious, too. Have it in my Tahoe.

 

[PNWMuseumman]

I don't have the first hand experience you're looking for, but your Denali should have a 4l65, so the servo is the same as the 4l60. The only difference is the awd system, but I don't see why that would mean you couldn't / wouldn't do it.

I've had thoughts of doing it to my Denali as well, so I'm curious, too. Have it in my Tahoe.

Did you notice a big difference on your tahoe?

 

[HiHoeSilver]

Did you notice a big difference on your tahoe?

When my right foot is down, yeah. Under normal conditions, it's not obvious, but at higher load, especially WOT, it's night and day. On even a slightly slick road surface, my 1-2 shift will break the rear loose.

 

[OR VietVet]

I am getting ready to do this to my Tahoe within the next 3-4 days and look forward to the difference.

 

[RaiderRodney]

I am getting ready to do this to my Tahoe within the next 3-4 days and look forward to the difference.

I want to do this myself, anxious to hear what you think.

 

[OR VietVet]

I will post here about what I experience after doing it. I am really looking forward to see what I can feel from this.

 

[J Mac]

My 04 Denali has the Vette servo installed. It was installed to help with towing our camper. Shifting definitely improved with the servo installed. In fact after the install, there are times the front tires will chirp (AWD remember) when going from 1st to 2nd under a heavy foot (not when towing of course).

 

[PNWMuseumman]

My 04 Denali has the Vette servo installed. It was installed to help with towing our camper. Shifting definitely improved with the servo installed. In fact after the install, there are times the front tires will chirp (AWD remember) when going from 1st to 2nd under a heavy foot (not when towing of course).

Thank you Sir! We were quickly becoming the merry band of misfits all waiting to hear how it works!
Thank you for the feedback!

 

[rockola1971]

The only addition the corvette servo adds is more holding power for the 2-4 band which ONLY affects 1-2 shift and 3-4 shift. The servo adds about 50% more surface area for the hydraulics to act upon when 2nd or 4th is commanded. This causes the band to be applied to the sunshell and holds it stationary with roughly 50% more holding power than your factory setup. This servo is a must for towing. Towing in 4th is one of the many killers of our transmission model. I simply do NOT recommend towing in 4th, not saying you cant just that It will reduce the life of your transmission, especially when the oem servo is in there. The tow mode switch on the end of the gearshift mostly gets rid of the hunting between 3rd and 4th which destroyed the father to our transmission model...the TH700R4. Hunting will cause the 2-4 band get applied everytime the tranny hunted back to 4th from 3rd and would prematurely wear out the 2-4 band which would flood the tranny with debris from the 2-4 band slippage and cause a early death to the tranny.

Honestly you cant go wrong with putting in the corvette servo. It is such a cheap and very easy "mod" and it will pay for itself in extending the life of the tranny.

 

[adventurenali92]

Damn now I’m interested in this... curious to see what the process looks like for install...

 

[Mechanic421]

There is a separate servo for 4th apply.

 

[rockola1971]

Damn now I’m interested in this... curious to see what the process looks like for install...

 

[HiHoeSilver]

Damn now I’m interested in this... curious to see what the process looks like for install...

Info and best part source:

https://blog.oregonperformancetransmission.com/

By far the best install write up:

https://www.performancetrucks.net/f...22/corvette-servo-install-w-alot-pics-476223/

 

[PNWMuseumman]

Info and best part source:

https://blog.oregonperformancetransmission.com/

By far the best install write up:

https://www.performancetrucks.net/f...22/corvette-servo-install-w-alot-pics-476223/

You aren't kidding! That is a phenomenal write up on how to do it!

Thank you!

 

[PNWMuseumman]

Just got a quote to do this from a shop I've worked with before for $361.00 out the door...

That seems awfully high. I may just have to take a stab at this myself!

 

[HiHoeSilver]

Just got a quote to do this from a shop I've worked with before for $361.00 out the door...

That seems awfully high. I may just have to take a stab at this myself!

I did mine in my driveway when it was empty while I did the fluid and filter change. Added an hour(ish) and a little shoulder pain to the job was all.

1. Be careful not to pinch the o rings.
2. Be ready to call that snap ring a few names (parental advisory).

 

[rockola1971]

Just got a quote to do this from a shop I've worked with before for $361.00 out the door...

That seems awfully high. I may just have to take a stab at this myself!

$361 is ridiculous. They are trying to screw you for an hour labor tops and they know it.

 

[latvius]

You aren't kidding! That is a phenomenal write up on how to do it!

Thank you!

Good write up but note a few things, he is doing it on a pickup not a SUV. Not sure on the Denali but on my Tahoe the pin won't come out it hits the floor board. If it was about 3/8 shorter would be fine. So I had to bend the heat shield and pound the floor board with a hammer and punch to get the clearance to get it out. That was easy and fun lying on my back with no room and limited visibility.
2nd most important thing that he does not emphasize enough the last step. Getting the metal ring in properly on the servo cover. You know what happens if you don't? The cover blows off cracking the case of the transmission and you get to go buy a new transmission + core charge. Keep in mind you cannot see the entire ring seated only a portion of it. You need a mirror or something to ensure it is seated.

 

[jmm121783]

So this is works fine on all trucks including AWD, 2WD and Selectable? Does this extend the life of the transmission even if you don't tow? I feel like the transmission and its controller or whatever is controlling the downshifts and when the tranny chooses to shift is the culprit for all the weird shifts I see daily when driving the truck. It just feels like the tranny doesn't downshift when it is supposed to and then when it does downshift it goes too far down, blah blah....I just feel like the stock GM program for the tranny is JUNK.