tranny or u-joint problems

[tphsmith]

transmission? u-joints ?

I drive an 81 1/2 ton with straight 6 in it. I assume the transmission maybe is a 350. well when I put it in gear it makes a loud clunk noise. I thought ok look at the u-joints. I dropped the drive shaft. and I have not yet removed the u-joints from the drive shaft yet but the seals look good they are not dried out. the joints I grab in my hand while the joints are still on drive shaft and I have drive shaft on the work bench. I dont see any unusual movement from the u-joints. so I started the truck with out drive shaft in and shifted from reverse to drive no noise sounds good. but when I put it in park with the motor running it makes a noise that I dont like................ HELP

[walker]

It may be play in your rear gears. Jack the rear up and turn the pinion back and forth by hand to see how much play is in it.

[Deltaskier]

What he said.

[Chevy67Tk]

If your hearing a ratcheting sound when you put it in to park with the engine running and no drive shaft, that is the parking paw trying to engage on to the output carrier while it is still spinning. I wouldn’t do this too often, as there is a chance of shearing off the paw.