weird! Shudder on take-off after R or N

**bigjim** · 07-11-2008

I'm baaaaaaaaak . . . Now it's a weird take-off problem

Took everyone's advice back in March and replaced the 4t65 in my hi-mileage 2000 GPSE.

1st used replacement was junk. Mechanic replaced it

2nd used replacement ok except for "THE PROBLEM" (more later) Mechanic replaced it

3rd used replacement ok too except for "THE PROBLEM" Mechanic had it rebuilt

3rd used replacement rebuild ok too except for "THE PROBLEM" Mechanic is presumably hiding out till I can get my hands on him monday morning.

So what's "THE PROBLEM"?
TRANSMISSION SLIPS & SHUDDERS LIKE CRAZY. . .
ONLY after car is very warmed up, like after a trip to my mechanic 3 counties away, and
ONLY on first couple of moderate take-offs, and
ONLY after car has been in R or N.

1-2, 2-3, 3-4 shifts are fine.
and take off is fine as long as shifter doesn't go to R or N again.

I am afraid to turn my mechanic loose on this one because I'm afraid something will just keep getting worse & his warranty coveage is short. I can't believe I'm having the same problem out of 3 transmissions. I'm losing patience fast & mechanic is losing hair even faster. Step right up & give me your best guess. Maybe it's not even a trans problem.

"Nothing drives like a Pontiac" (bit I do wish it would take off right)

**Trannyman95** · 07-11-2008

I could easily point to a lot of trans problems that may cause this, BUT you have had 3 different transmissions in the car that do the same thing. Has the engine been thoroughly checked out and all sensors for engine and trans verified within proper working range with a scan tool? Has a pressure gauge been installed on the transmission? Has the maf sensor been check out OR you could unplug it to see what happens but of course the check engine light will come on and you will need the code cleared after reconnecting it.