Vette Servo Problem

ajcain79 · February 23, 2010

So, I installed my new vette servo yesterday. Total time was about 1 hour 15 minutes. Pretty easy. I took the truck for a test drive and it was good. Shifts were slightly firmer, yet still smooth. I drove about two miles and all was good. Then I slowed to make a u-turn to head back home and the truck would not shift out of first gear. So I'm cruisin home at 15-20mph when the truck starts to slow (like the clutch is slipping). I stopped and looked under the truck to see all my tranny fluid on the ground and a trail of fluid where I had been. So I got my dad and his F150 to pull me back to the garage. (yeah I know, he wanted to take pics of the Ford pulling the GMC. ...har har har)

I crawled under the truck and removed the heat sheild. The cover snap ring fell off as soon as I moved the heat sheild. (I'm lucky that it wasn't laying on the road somewhere). The servo cover was still in place, but it was cocked a little causing the fluid to run out. I took the cover off and pulled the guts out. Everything looks to be in good working order. The cover has a little gouge in it. I don't think it's a problem, but I'm going to get a new cover anyway.

My theory is this: When I put the cover snap ring on I didn't have it fully seated all the way around the circumference of the groove. It was seated on the bottom where I could see it, but the top (where I couldn't see) it must not have been set correctly. Then the pressure eventually popped the cover out causing the fluid to leak. When I lost enough fluid the truck would only drive in 1st gear and eventually wouldn't move at all when I lost even more fluid.

Does this theory sound feasible? Can anyone else think of any other possible scenarios that would cause the cover to pop off? What other damage might I have caused?

Tomorrow, I'm getting a new cover and o-rings. Then I will reassemble the peices and top off the fluid later this week when I have time.

p.s.- Before the fluid ran out it was running really well. I'm excited to get it put back together!

brims · February 23, 2010

That sounds feasible. But check the transmission housing for any cracks, I've seen a few threads where someone didn't get the ring seated properly and the pressure behind the cover cracked the transmission housing.

ajcain79 · February 23, 2010

That sounds feasible. But check the transmission housing for any cracks, I've seen a few threads where someone didn't get the ring seated properly and the pressure behind the cover cracked the transmission housing.

I'll check for cracks.

It only took me a couple of minutes to get the cover snap ring on. I remember thinking "Gee, what's so hard about that? I don't know what everyone else was complaining about."

Hind sight is 20/20 I guess.

brims · February 23, 2010

If all is good, I'll give you a tip I figured out when I did mine. Take your spare jack, assuming you still have it, put the bottom of the jack against the frame then put the top of the jack against the nub on the cover, use your fingers to crank it out just enough to give you room to insert the ring. You can let it sit there and thoroughly check to make sure the ring is seated. Hope all is well on your tranny.

700 sportsman · February 23, 2010

Your theory is very feasable, as the fluid moves the parts, and if the fluid can't build pressure, it won't shift. Here's an animated display of how they work, and where the fluid goes etc.

ajcain79 · February 23, 2010

Your theory is very feasable, as the fluid moves the parts, and if the fluid can't build pressure, it won't shift. Here's an animated display of how they work, and where the fluid goes etc.

What kind of damage would occur from running a transmission with a huge amount of fluid loss? It was only for a short period of time. Someone I talked to thinks it should be just fine.

ajcain79 · February 23, 2010

Well I got my new o-rings , seals and cover today. I also noticed that one of the ears on my vette servo was cracked. So I had the transmission shop give me a whole new vette servo setup. All of this stuff totaled $4.58! I couldn't believe it, but was thrilled to pay it!

Tomorrow morning I will put the truck back together. I'm just going to put the OEM parts back in for now. If no problems arise in the next couple thousand miles, I will re-install the vette servo.

700 sportsman · February 23, 2010

I think you should be fine, since it was such a short time, your tranny didn't over heat, or anything, so IMO it should be fine

brims · February 23, 2010

I can't see installing the Corvette servo exacerbating any damage that may have occured. I also doubt you did any damage. I accidentally arc welded a hole in my trans cooler lines on a 72 El Camino once, didn't know about it until my dad and I drove it out of the garage and there was a trail of ATF on the ground. I forget how much we had to add, but it was a lot. I'd go ahead and put the new servo in.

ajcain79 · February 24, 2010

I can't see installing the Corvette servo exacerbating any damage that may have occured. I also doubt you did any damage. I accidentally arc welded a hole in my trans cooler lines on a 72 El Camino once, didn't know about it until my dad and I drove it out of the garage and there was a trail of ATF on the ground. I forget how much we had to add, but it was a lot. I'd go ahead and put the new servo in.

The reason I was gonna run it a couple thousand miles in the OEM configuration was to make sure no problems arise. If a problem did show up, I wouldn't want to give the dealership a reason not to cover it under warranty.

I'm just playing it safe. I can re-install the vette servo in a couple months.

ajcain79 · February 24, 2010

On a brighter note: I was planning on changing my tranny fluid soon anyway. Since I dumped most of it on State Road 18, I guess this counts.

ajcain79 · February 26, 2010

Everything is now re-assembled with oem parts and the truck runs perfectly. woohoo! In a couple months I'll put the vette servo back in.

It took 4 7/8 quarts of ATF to fill the transmission. The transmission only holds 5 quarts! Like I said before, I was wanting to change my tranny fluid anyways.

700 sportsman · February 26, 2010

wow, I guess you were running low on fluid. I think you'll love the servo when you put it in, I know in my 96 is sure made a world of difference

ajcain79 · February 26, 2010

wow, I guess you were running low on fluid. I think you'll love the servo when you put it in, I know in my 96 is sure made a world of difference

I had the vette servo in for a couple miles and I did like it. I was a beautiful nice firm shift without being harsh. I had my dad with me and he didn't even notice the shift.

....then all the fluid poured out.

gmtech4 · February 26, 2010

put it back in ,you'll be fine ,

pan hold 4 liters,

tranny holds approx 10L .

empying a tranny will disconnect any clutches,rob the lub circuit which is ok if not run long,it will heat up the pump however but they can handle it cause if the truck stops moving ,it gets shut off ,so relax ,its fine .

I am still on the fence about putin in a vette servo after my SRTA warranty is up in a year and a bit ,

a testimonial for ya ,I put in my 85 C10 burb (700r4) w/6.2 diesel),a SRTA in ,drove the piss out of it ,it slammed hard into 2nd alot with foot in firewall and I took it apart after 270K KM and it was perfect ,I used the 3-4 clutch for my next truck which got its engine as well,so slammin into gear is actually good instead of slidding in for comfort right guys?