j30. transmission won't pull once engine warms up.

[icandoit]

You guys are doing a wonderful job of sharing top technical information and helping folk solve their vehicles' nightmares. I appreciate that. I am new a new member. I have used your posts in the past to solve problems with my 2001 QX4 when it had a intake valve timing sensor problem. That saved me about $300 bucks at least.I have a '94 J30 with 134,000 miles. The car always runs good and the transmission shifts very well. I inspected the transmission fluid one day and find out that it was almost as black as a charcoal. So I changed the transmission fluid. The car ran well for about a week. Then one day at a bank's drive thru, the car refused to move after my transactions: I pushed the transmission shift to the neutral position got out of the car and pushed it to the side and called for AAA towing service. The transmission check light did not come on. Next morning I tried to drive the car, it actually drove for about 5 miles then stopped moving at all, even though the engine is still running. I cut the engine off, allowed it to cool and drove home. A technician once told me that the burnt out ATF fluid and grinded metals actually kept the gears together after so many mileage without changing the transmission fluid but I screwed up that togetherness by changing the fluid. I had thought it was my torque converter because I kept hearing some loud grinding noises when engine idle in park and it became increasingly difficult to push the shift selection from park to drive. SUMMARY. transmission WILL MOVE CAR WHEN ENGINE IS COLD. BUT WILL NOT MOVE AT ALL WHEN ENGINE IS HOT. YOU COULD CUT OFF AND TURN ON THE ENGINE AS MANY TIMES AS YOU WANTS. IT MAKES NO DIFFERENCE.Somebody help me!!! Do I change my torque converter, the transmission and converter or change something else.Thanks for your helpicandoit.
Modified by icandoit at 4:13 PM 9/3/2007

[93jdirty']

Mine did the same thing, call some salvage yards, i got a new transmission for 300 and its been fine ever since.

[nkawall]

when you say "it wont move"...do u mean that literally or as if its moving slowly?

[icandoit]

When I say it won't move. That's exactly what I mean. The only way the car can move is for you to move the shift knob to neutral, get out of the car and physically push it. You could sit inside the car and rev the engine as long as you want to, but it ain't moving an inch. However, when the engine cools down (usually after couple of hrs or over night, the car is ready to go and you can hear the gears shifting and changing without any problem. As soon as the engine warms up, the trannny stops pulling. You are either left in the center of the street or lucky enough to let it roll off the street to the curb. Somebody please help.

icandoit.

[Q45tech]

Very common when worn acidic ATF [from not replacing every 30k/4 years]causes clutch material to clogg in rad heat exchanger and starves the rear planetary gears galling them and causing wear metals.

There is an old TSB about this every condition and solution by replacing radiater to get a new heat exchanger.

Before you crank car with replacement transmission make sure you have flushed all hardlines to rad and replaced rad otherwise you'll destroy new one fast.

http://transmichigan.com/html/why_flush.html

http://www.autobarn.net/noname8.html