I've got a 1984 5.0 AT trans. knocks at idle in park. Once you shift into gear (D or R) it knocks unless you have your foot on the brakes.Slight knock below 2500 rpm, gets a little louder until 4000 rpm, above 4000 no noise at all.Also it makes no noise while accelerating, once you let off gas to cruise noise comes back. This is the 5th tranny always the same problem. Any guesses?

 

cracked flywheel?

 

sounds alot like a cracked or loose flywheel to me too especially since you noted this isnt the first transmission with this problem ...

does it change with engine rpm ?

what i mean is does it knock faster as the rpms climb?

 

I have changed flywheel twice with brand new ones. Also Changed torque converter (stock replacement) also brand new poly trans. mount

 

Automatics have flexplates, not flywheels. (sorry, I had to-it bugs me when people use the wrong terms)

 

id guess that the converter bolts are hitting somthing....

and if this has happened to more then one trans, i would be looking at things other then the trans...


if the car isnt moving for the noise, its not the drivetrain... so id be looking at the back of the motor.......

 

First I understand that that in a parts catalog a/ts have flexplates not flywheels. But after sellling auto parts for 5 years people still seem to come day after day calling it a a flywheel.So I feel your pain sorry.Second with the tarns out motor make s no noise while runnig with the flexplate installed bought brand new flexplate bolts for both new flexplates. No clearance issues.With the car on lift noise is clearly coming from trans. Car goes into gear fine shift good, if not a little hard especially going into second.

 

perhaps all these trannies have worn front pump bushings. my friends did the same thing. replaced the the front pump bushing and voila knocking noise was gone.


are you using the same torque convertor on all these trannies?

 

changed torque converter twice.

 

[QUOTE]Originally posted by mystikkal_69
[B]perhaps all these trannies have worn front pump bushings. my friends did the same thing. replaced the the front pump bushing and voila knocking noise was gone.

Did his knocking go away with brake pedal depressed before you changed front pump bushing?

 

his knocking went away while in gear, brake applied. while not in gear it did knock @ idle and at higher rpms.

 

I'll see if I can check into that. By is it a bushing or a bearing? I went over to advance auto the only part they could find was a bearing. I have only pulled the front pump out of a 700r4 once and I can't picture the bushing in my head right off hand.
Thanks