bobd54321

I searched briefly but didnt know what exactly to look for. My 02 Sierra trans went out and I swapped in the trans I salvaged from my garage fire. The wiring had melted and the solenoids were bad. Knowing this I removed my valve body and wiring and installed it into the salvaged unit along with anything that looked melted. I filled up the trans and the torque convertor and installed them. I drove it about 20 miles and changed the fluid to make sure everything was out of it. The fluid was clean when I changed it. All the gears shift well even after about 1500 miles and during WOT shifts.

The only problem I have is that I can shift it into reverse from any gear and it shifts slowly and then when I press the gas it jerks and then engages. Also at times I notice that when I am at a stop light in drive and i let my foot off the brake and hit the gas it jerks then accelorates, but hardly noticable.

The salvage unit had approx. 3500 miles and the torque converter wasnt damaged.

Does anyone know would could be causing this problem?

Thanks
Bobby

Gilbert@Ace Racing

Well, if it went through a fire the first thing that comes to mind is defective rubber lip seals at the reverse input piston. It is possible that these seals may have been compromised when it got hot.

Also, depending on how hot it got there could be a problem with the plastic filters at the valve body melting... they are fragile.

There are other seals that may have gotten too hot as well... the seals on the input shaft could have gotten too hot if the shaft was exposed to too much heat for instance.

But, the cool thing is it has been shifting well. That's impressive for a unit that went through a fire and sustained minor damge in the process.

Any warning lamps on?

g

bobd54321

No lights on. The transmission was still in a truck when it burnt and the input and tale shaft seal (protected by transfer case) was in good shape as was the torque converter. I put the valve body out of the original transmission in it and a new filter. I do have hptuners to check things if needed.

Gilbert@Ace Racing

I see. That's good info.

What is the current fluid condition? What were the issues with the unit this one replaced... was it remotely similar?

I gotta say that Automatics and heat really do not mix. What was wrong with the solenoids and the wiring? Heat stress you think?

I could be wrong though. It might be best to have a professional take a look at it.

Are you anywhere near D/FW? If so bring it over!

g

bobd54321

Nope, I live in KY.

The fluid is new, the wiring and solenoids were melted so I put my wiring and complete valve body in.

The one that went bad reverse and first went out. Reverse sound like a metal grinder and first would move and operate but it grinded some.

I dont mind dropping the pan and checking stuff if possible. All the seals looked fine and they had a rubber texture not a crisp texture from heat.

Gilbert@Ace Racing

Which seals? The seals I am referring to can only be handled with a complete dissasembly.

But, again I could be out in left field with this one because of the fire comments. But, these units very rarely... and I mean very rarely have issues in Reverse.

g

bobd54321

I was just talking about the ones visible on the outside, tale shaft, input shaft, oil filter seal, The one that seals the round thing on the side. I didnt get inside the trans, just unbolted the pan and valve body and wire harness and swapped. I though that this may have been a ball sticking in the valve body or maybe low oil pressure at idle,or something simple because it all seams to work for the most part. I really dont know, I am kind of blind when it comes to transmissions.