Mos

Hello everyone,

unfortunately I got some problems with my transmission.
But I'll have to tell the story first.

I've had the problem (4L60E - 2004 Silverado 4.8 2WD) with the TCC lockup. After a while it would threw the code "Transmission component slipping", it would result in harsh 1-2 shifts and high ATF temperature.
After replaceing all the solenoids, as well doing a filter and fluid change the truck drove for one week without a problem.
Unfortunately after the week the same problem would occur again. The Tech2 tool showed a TCC slip around 150-200rpm at normal cruising at 60 mph.

Last weekend I've installed a rebuilt transmission along with a torque converter in my truck.
Went out on a first test drive today and now I'm sitting here with the old problem still happening as well two new ones:
1. At cruising speed the TCC still has a slip around 150rpm and sometimes throws the code P0894 (Transmission component slipping)
2. Transmission has harsh1-2 shifts even after P0894 DTC is cleared.
3. While in drive or reverse the truck only creeps forward with very little power. When accelerating from a stop there is a bump comming from the transmission and then truck drives in normal manner.

After I installed the rebuilt transmission, I've done a TAP reset using Tech2.

mountainmanjoe

this is the problem with rebuilding/rebuilt transmissions. Hardly anybody knows how to do it properly. And if you change out one bad part and leaving everything else, you're just kicking the problem further down the road.
The only reliable solution is to get a re-manufactured and performance tested transmission with guarantee. You also need to completely flush out the cooler and lines, and the TCM has to work (I had one fail at around 40k).

(always post your vehicle info please)

Mos

Hi, the truck is 2004 Chevy Silverado 1500 2WD with the 4.8 L engine.

I was on a second test drive today and I've noticed that the strange bump when launching from a complete stop only occurs when the transmission is warm. When i started driving everything worked fine.

Called the shop today and told them what's going on with the transmission. The guy said the harsher 1-2 shifts result from the corvette servo they have installed as an upgrade to the transmission. I've sent him the error code and the Tech2 data while cruising at 60mph and he will look into that and call back... Unfortunately the place is a 2.5h drive away, so it's not easy to get there.

This is the data from Tech2 to while driving 60mph:

mountainmanjoe

"upgrade"

Hydancell

I had issues with my old Mustang's gearbox after a rebuild. It was supposed to solve shifting problems, but I ended up with similar issues like harsh shifts and slipping.

I eventually found a specialist who pinpointed the problem to a faulty valve body that wasn't replaced during the rebuild. It was a pain dealing with the same symptoms after investing in a rebuilt transmission.

Mos

Yeah the truck is finally running normal again.
They had it in their workshop back then and were working for quite some time on it.
But I don't really figured out what the real problem was with it...