restoring a 72 cutlass with a TH400 tranny - have it all on stands and tires off. Decided to start it up today and then for the heck of it shifted to reverse and then drive. both appear to spin the back wheels (wheels actually off) - but then when I shifted back to park it had a 10 ish second grinding sound?

never worked on a transmission so I thought I would ask. I know that tranny oil needs to be flushed and filter replaced but I don't think that would cause the noise.

Thoughts??

ciao

L

 

did you press the brake pedal before going to park? you have to stop all the rotation of the driveshaft because when you go to park you are pushing the park pawl into the slot that locks the driveshaft (the reason the car wont roll in park). if the driveshaft was moving you are forcing it to slow the rotation with the pawl and thus the grinding.

 

I found out the problem and it was exactly as the reply thought. The other issue I found out was that my nine year old wasn't 100 % sure when he said the wheel stopped moving er...could have been moving really slowly... er yeah dad it wasn't stopped... but it did slow down....

once I knew it was fully stopped (put in neutral and checked myself both sides of the car) and then put into park no issues.

thanks I love this forum for the wealth of knowledge and ability to help out...

thanks again.

 

Blame it on the kid.
My daddy always told me that's what I was born for.