automatic transmission information

I used to have a 2005 Grand Prix GXP that was the 5.3L V8 engine. It was the worst car I ever had as far as reliability was concerned. When I bought it (used) I was not disclosed that it had 4 transmission rebuilds. After I bought it, I started having problems... The issue was that when I would come to a stop at a traffic light or stop sign, I would lift my foot off the brake and proceed to press the gas pedal and the RPM's would shoot up but the car was not moving forward... randomly it would eventually just go THUNK and kick it into gear and cause the car to jolt forward... once moving, the car and transmission ran fine. This happened often enough that I eventually got fed up and asked my dealership to look into the problem. Of course, when the technician took the car out for a drive, he never found any issues in the way the car performed. He handed me small ODB connector that was attached to a little recorder that monitored my cars activity.

Then one morning I was exiting my underground parking, I had to drive up a tall angled ramp area to get onto the ground level.... when I accelerated up the ramp, same thing, revs up.. no go.. then CLUNK the wheels start spinning and off I go. The recorder revealed absolutely no information at all.

Eventually I had to give in and have my car go in for service for the who know how many'th time. It eventually had 2 seperate transmission rebuilds, and everytime it would be great for a few hours of driving, and then it would do it again. After a total of 6 transmission rebuilds, and no help from GM, I decided to say **** it and sell the car. Never been happier.

The thing that always bothered me was that no one had any idea or information on why these things happen. Not the master mechanic, not GM, no one. They just told me it was probably the "Clutch" or "Torque Converter" int the transmission but again, after 6 rebuilds, why would this happen? I have never been able to get a straight answer... if it wasn't for those problems, I really liked the car but it was too much hassle. Any ideas?


Pressure control solenoid. very common on the 4t65e's. problem is the replacement solenoids dont last long either.
 
Hi Herman, Instead of adding 6th gear could you come up with a way to change the ratios of the 5th gear pair to reduce the overall ratio so it will drop the rpm by 500 to 800 rpm from where it is now at 75 mph.

u r asking a lot from a small automatic trans shop.:(
 
What about changing the ratio in the final drive? It would bring all gears up but I dont think it would be bad. Should be an easy fix?
 
I've always been told not to flush. Drain what comes out and replace.

there is some truth to that.
if u take out real old fluid that is like a brown gunk (that is old and thick)
and u replace with new fluid that is thin then there is the possibility the trans might start seeping fluid.
i think changing far out weights negative of not changing.
 
proper way to change transmission fluid.:D

if it has bottom pan
remove bolts from pan (have large drain pan under)

remove filter use safety glasses tear filter open (filter inlet acts like a vacuum to suck up clutches,washers,rings and other debris)

replace filter and pan gasket
fill trans (4 to 7 quarts)

remove line going to radiator attach hoses. and put them in a container
start motor it will pump out 4 to 6 quarts (may have to add fluid while pumping)
if it very dirty u may have to use more till it looks good.

replace line to radiator and fill to add mark

road check then recheck the trans fluid. recheck for leaks.
if all is well u hand the keys to customer.

i know i make this sound easy believe me it is not that easy:(
 
What do you think about these newer automatic trans that say to never change the fluid if used under normal operation. My srt6 is that way
 
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