no roll

1990 c1500 5.7 700r trans. if truck is idling and in neutral it won't roll,as soon as the engine is turned off the truck will roll.Any and all help is greatly appreciated. Thanks Robert

Only thing that changes, that I can think of (which usually ain't much :biggrin: ), is vacuum to the brake booster. BUT, vacuum doesn't get routed to the booster normally, UNLESS the brake pedal is depressed. AND, there is residual vacuum after the motor is off...

I can't imagine how something could be broken in that system, that allows your problem...

Try this: block the front and rear wheel ABOUT 2 INCHES from the wheel, not against the wheel, or not too far away from the wheel. Don't use the e-brake. Get out, pull the booster vacuum hose from the booster, and see if it lets it roll TO THE BLOCK.

What happens if you give it some gas while in neutral? Sure sounds like something in the trans since the output shaft should be disconnected from the input shaft when in neutral.

//2000CAYukon

Hey thanks for the suggestions, Nothing happens when I try to accel. and when I take the vaccum line off there is still no change....will a lock up solenoid for the converter cause this????

It would stall in gear at a stop if the lock up solenoid was on all the time.

//2000CAYukon

1990 c1500 5.7 700r trans. if truck is idling and in neutral it won't roll,as soon as the engine is turned off the truck will roll.Any and all help is greatly appreciated. Thanks Robert


If this is the transmission partially engaged when the shift select is in neutral I would check for the shift cable. transmission cable, shift hardware for damage or if possible adjustment.

I have seen this where the transmission control arm has been damaged so as to cause this effect...by moving the cab shift select slightly you should be able to get into neutral. If this is found then my suggestion should be correct.....

If this is the transmission partially engaged ...

Automatic? Partially engaged? That's an interesting concept. :confused: