Vette Servo

jrod332 · September 25, 2009

I have done a lot of searching on this forum and on google. From what I have read installing a corvette servo is a pretty easy job and makes a big difference. I do mostly all my own work. Is this something thats easy enough to take on? And it I have read that it can be done without removing the tranny or anything else and in little time. I have an 05 crew cab silverado.

I definitely want to get a tune from justin and im thinking i should do this before.

This seems to be what others are buying.

Is this all I need?

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

dlstewart01 · September 25, 2009

http://www.gmfullsize.com/forum/showthread.php?t=98029

The hardest part is getting the snap ring back on the cover. Its easy to do after you get the hang of it. It takes less then an hour for the install. It took me several tries to get that dang snap ring back on. You really have to wedge something against the cover to push it in far enough then the ring will go on. You will think you need a third hand. Could be I'm just old and senile.

I went ahead and installed a 4th hold billet servo at the same time. The 4th servo is in the cover so you already have it out. It holds the overdrive band 40% tighter. Really helps me towing.

Rolling · September 25, 2009

This is one of the easiest, least expensive DIY mods you can do, and yes you will be extremely happy with the results. I have put these kits in my 07 NBS Silverado, my boss's 95 Burb, buddies 02 Denali, other new silverados, and a few older ones. The better condition the trans is in seems to net more impressive results. My truck has 24k on it now and still shifts as firm as it did the day I put this in.

Couple tips: Get a long prybar, you can use the exhaust pipe to leverage against to push the servo cap into the case to remove and reinstall the snap ring. This will NOT cause any damage to the exhaust system, you are not putting enough leverage against it.

Second, get a 90* pick to use to remove the old cover o-ring. This o-ring will be blue, the kit comes with 2. The blue one is the cover, red goes inside. Pull the old oring out of one of the grooves and cut it, and then pull it out. You are not re-using this and it almost makes the cover fall out.

On your truck you will have to dissassemble the servo out of the trans case, and reassemble it back in. Pay close attention to the orientation of the servo plates (which direction faces in and which side faces out) and what order they are in. Be very careful not to let the E clip become an "OH-SH!T" clip. You know, the kind that flies across the garage and you yell...Oh Sh.....

When you put everything back together, the seams in the servo plates need to be opposite of each other, kinda like stacking piston rings. I have found for reassebmly use the cap and fill it with ATF and use this little pan to soak the orings and black rings very well, make sure there is plenty of ATF on evertthing when it goes back in the case.

Back to the leverage against the exhaust pipe, this method makes it much much easier when pressing the cap back onto the trans case since the blue oring will want to stop in the snap ring groove. It will feel like it has properly seated but still must go one groove further. Make sure the cap is sitting straight on the servo rod and push it to the next groove. While you have it retained, the 3rd hand (everyone has a garage helper...right?) can put the snap ring back over the cap.

To make sure the cap is properly installed, take the prybar and push in on the servo cap. It should move in from the snap ring just a tiny bit...kinda like a button. If it is wedged in solid tight, be very careful and take it back apart and see what is binding. The servo must be able to move in and out just a tiny bit. That is how it applies and releases pressure in the trans band.

Rolling · September 25, 2009

Oh yeah, side note, check with your local GM tranny shop, they might have this kit on the shelf. Its been a pretty common upgrade for the 700R4 and 4L60e for years and years.

jrod332 · September 25, 2009

thanks for the input. I ordered it last night from oregon performance. Cant wait to get it in.

nbscanuck · September 25, 2009

Do it with the truck cold, that exhaust is RIGHT there. You will have proof you did it yourself (burns). I paid a mechanic to do it with the truck hot. Best $50 I spent

deyomatic · September 25, 2009

I have one in the 700R4 that I have but it was already installed in the tranny when I got it. From the driver's seat, what's different?

compulynx · September 25, 2009

I would like to hear from some techs on how this mod will affect NBS trucks with Tow/Haul. I was under the assumption that The T/H mode changed shift points AND pressures. If this is the case, then it seems that tha 1-2 shift in T/H mode could be really harsh. If you have a camper in tow, to me this could be bad on the drive train (drive shaft & differential)

I know the performance buffs like it, but what about those of us wanting to keep a smooth shift and long drivetrain life.

C

dlstewart01 · September 25, 2009

I would like to hear from some techs on how this mod will affect NBS trucks with Tow/Haul. I was under the assumption that The T/H mode changed shift points AND pressures. If this is the case, then it seems that tha 1-2 shift in T/H mode could be really harsh. If you have a camper in tow, to me this could be bad on the drive train (drive shaft & differential)

I know the performance buffs like it, but what about those of us wanting to keep a smooth shift and long drivetrain life.

C

In my 5th season of towing a camper with a vette and 4th hold billet servo. One of the better things I have done for towing.

Contrary to popular belief the Corvette servo does not make the shift hard, harsh too fast, it just improves it. Now if you do a tune and increase line pressure the shift will be very quick but not harsh or a banging shift. I have a tune.

The vette servo holds the band 18% tighter and the 4th hold billet holds the overdrive bands 40% tighter. No slipping, less heat. I can tow in over drive with out issues. In fact I don't even use tow-haul any more.

It is inexpensive and not a time consuming install, if you don't like it take it out and put the stock one back in. Nothing ventured, nothing gained, in other words you don't know what you look like till you have had your picture taken.

5th season of towing, I believe if I were going to have problems I would have by now.....

P71_CrownVic · September 25, 2009

I went ahead and installed a 4th hold billet servo at the same time. The 4th servo is in the cover so you already have it out. It holds the overdrive band 40% tighter. Really helps me towing.

Is this something extra I have to buy? And if so, where can I get it....and how easy it to install (I assume pretty easy...)

Thanks for your input on this. It's good to hear from people that have been running this for years.

Edit: Is it this: Link

dlstewart01 · September 25, 2009

I went ahead and installed a 4th hold billet servo at the same time. The 4th servo is in the cover so you already have it out. It holds the overdrive band 40% tighter. Really helps me towing.

Is this something extra I have to buy? And if so, where can I get it....and how easy it to install (I assume pretty easy...)

Thanks for your input on this. It's good to hear from people that have been running this for years.

Edit: Is it this: Link

Yeah thats it. It replaces the cover, thats where the 4th hold servo is. I used a Sonnax brand.

http://www.sonnax.com/part_summary.php?id=4356&pl=3

music · September 25, 2009

Contrary to popular belief the Corvette servo does not make the shift hard, harsh too fast, it just improves it. Now if you do a tune and increase line pressure the shift will be very quick but not harsh or a banging shift. I have a tune.

If I understand correctly, you have a Diablo tune... so no TCM modification? Tow/haul supposedly increases line pressure (from what I've read), and definitely changes shift points. What about tow/haul do you not like?

dlstewart01 · September 25, 2009

Contrary to popular belief the Corvette servo does not make the shift hard, harsh too fast, it just improves it. Now if you do a tune and increase line pressure the shift will be very quick but not harsh or a banging shift. I have a tune.

If I understand correctly, you have a Diablo tune... so no TCM modification? Tow/haul supposedly increases line pressure (from what I've read), and definitely changes shift points. What about tow/haul do you not like?

On my 05 I can eleminate much of torque management with the Diablo, It has that feature for GMT800s, which I have done. Driveability is greatly improved.

Now to Tow-haul. I have no torque management, and with the mods I have done, I don't need to hold the shifts longer and I like getting to overdrive and lock-up sooner. I have quick shifts, no slipping between gears or any other time, no overheating in overdrive, and my trans does not continually downshift or hunt for gears. I don't need tow-haul. Maybe I am just lucky and hit the righ combination. I know I would not change anything.

dlstewart01 · September 25, 2009

You have got to experiment and try different stuff to know what works for you.

Someone told me once, why pay some mechanic a lot of money to screw up your vehicle when you can screw it up your self a hell of a lot cheaper. Made since to me.

The last transmission I broke was a two speed powerglide and that was in 1963. I started putting shift kits in GM trans in the 70s. I have not had one go bad on me in all these years. I have put a lot of miles on some of them. I drove 80,000 miles a year for around ten years. If you try something and it does not work, un do it and try something else. There is a lot of talk on the Internet but only you will know when you try it.

Of course I restored cars and motorcycles for over twenty years and not every thing I tried worked out. I am Retired now and can't remember half the stuff I have done.

I know I put energy suspension polyurethane body mount bushings in my 05 last year. They stayed in there one week. I will never do that again. Rode like a log waggon.

Well any way got to haul a bunch of girls in the back of my truck in a homecoming parade. Have fun.