Corvette Servo

Vortec-Z71 · February 16, 2011

So I've been reading some reviews about custom tunes, probably going to go with BlackBear. I've noticed that a few people have installed Corvette servos in their transmission before the tune. I've got 100,00 on my truck right now. It still shifts pretty smooth, which I like. What will the servo actually do? Is it worth upgrading to before I get my tune?

[email protected] · February 16, 2011

If you like a smooth shift, you don't need to mess with a corvette servo, they stiffen the shifts(make em' faster) for better quarter mile times and whatnot.

Sly · February 16, 2011

So I've been reading some reviews about custom tunes, probably going to go with BlackBear. I've noticed that a few people have installed Corvette servos in their transmission before the tune. I've got 100,00 on my truck right now. It still shifts pretty smooth, which I like. What will the servo actually do? Is it worth upgrading to before I get my tune?

I did this mod on my Denali a few months ago when my truck had 112K on it. It does not make the shifts harsh at all. It does shift quicker but still smooth. I would also do the 4th gear billet apply piston and cover. I got mine from Oregon performance. Great mod wish I had done it when I bought the truck.

http://www.oregonperformancetransmission.c...ry_Code=4L60EHP

http://www.oregonperformancetransmission.c...ode=NTP-K51828C

music · February 17, 2011

Doesn't tow/haul mode basically do the same thing, but via the PCM adjusting (upward) the line pressure? I don't *know*, but I thought it did?

GMstrong · February 17, 2011

Some people like the vette servos some would just throw a 3200 stall in it then put racing clutches and bands in the trans and call it a day.And a nice shift kit.nice setup their

Garrett Street · February 17, 2011

I have a Corvette servo in my truck. If you like a smooth shift do not get one. It makes the 1-2 shift on the neck snapping side. But, if you're into a faster shift, it could be for you.

DwayneJ · February 18, 2011

Only way I see the Vette servo making the shift harsh is if you use it with jacked line pressure in the programming.

Once my tranny is out of warranty I will be putting one in seeing as GM saw fit to even put it in my 96 Roadmaster wagon.

The Vette servo is RIGHT, the way the trucks are setup stock with nearly imperceptible shifts is wrong. I am not saying hard shifts are good, that will break this tranny, but quick and positive shifts are good and that is not stock.

What the servo does is provides more area for the hydraulic pressure to apply the second gear band, just playing with the programming tries to accomplish more positive band hold by just jacking pressure.

music · February 18, 2011

What the servo does is provides more area for the hydraulic pressure to apply the second gear band, just playing with the programming tries to accomplish more positive band hold by just jacking pressure.

Wouldn't the result be the same? Force = pressure * area. The servo increases area to a fixed value, but the PCM can modulate pressure to variable points.

chas0218 · February 18, 2011

Only way I see the Vette servo making the shift harsh is if you use it with jacked line pressure in the programming.

Once my tranny is out of warranty I will be putting one in seeing as GM saw fit to even put it in my 96 Roadmaster wagon.

The Vette servo is RIGHT, the way the trucks are setup stock with nearly imperceptible shifts is wrong. I am not saying hard shifts are good, that will break this tranny, but quick and positive shifts are good and that is not stock.

What the servo does is provides more area for the hydraulic pressure to apply the second gear band, just playing with the programming tries to accomplish more positive band hold by just jacking pressure.

x2

I'm pretty sure it only affects the 2-3 shift.

If a truck is stock and well maintained I wouldn't worry about breaking anything, there is just not enough torque/hp there to break the tranny.

With faster and firmer shifts it doesn't allow the tranny bands to slip as much keeping the tranny from wearing as quickly.

I would recommend a corvette servo and shift kit if you want more bang for your buck. With 100k on the tranny I would be a little hesitant to change anything...

Just my .02 cents

DwayneJ · February 18, 2011

I suppose you advocate traction weight in the bed INSEAD of good tires too? Just because there is more than one way to skin a cat does not mean all ways are equal. Your mind is clearly made up and no amount of information or expeience will change it.

What the servo does is provides more area for the hydraulic pressure to apply the second gear band, just playing with the programming tries to accomplish more positive band hold by just jacking pressure.

Wouldn't the result be the same? Force = pressure * area. The servo increases area to a fixed value, but the PCM can modulate pressure to variable points.

FargoZ71 · February 18, 2011

Honestly, Save the $ you'd spend on your Vette Servo since your already getting a tune. My tune from BBear increased line pressures in my transmission, and the shifts are all noticably faster and smoother. Just have him program it and spend the vette servo $ on a tank of gas.

music · February 18, 2011

I suppose you advocate traction weight in the bed INSEAD of good tires too? Just because there is more than one way to skin a cat does not mean all ways are equal. Your mind is clearly made up and no amount of information or expeience will change it.

?? Why do you say that, I was asking a question... (?) I'd be interested to hear the difference between a larger surface area servo vs increasing line pressure via e-controlled pressure regulation. I really don't know... so I'm asking.

transman618 · February 18, 2011

The Corvette servo allows for equal apply pressure across the servo piston for more positive band apply and hold. Jacking up line pressure wont do that. In fact, jacking it up too high stresses the pump and will break pump rotors, a big problem in 4L60E's.

transman

I suppose you advocate traction weight in the bed INSEAD of good tires too? Just because there is more than one way to skin a cat does not mean all ways are equal. Your mind is clearly made up and no amount of information or expeience will change it.

?? Why do you say that, I was asking a question... (?) I'd be interested to hear the difference between a larger surface area servo vs increasing line pressure via e-controlled pressure regulation. I really don't know... so I'm asking.

txab · February 18, 2011

The Corvette servo allows for equal apply pressure across the servo piston for more positive band apply and hold. Jacking up line pressure wont do that. In fact, jacking it up too high stresses the pump and will break pump rotors, a big problem in 4L60E's.

+1

music · February 18, 2011

The Corvette servo allows for equal apply pressure across the servo piston for more positive band apply and hold. Jacking up line pressure wont do that. In fact, jacking it up too high stresses the pump and will break pump rotors, a big problem in 4L60E's.

Thanks Charles. Good to learn...