Drive Train noise

[Awann99]

For about a month every time I shift my 1969 gmc 1500 into drive it would make a loud ping noise. It has a th350. Two piece drive shaft and 12 bolt open diff. The noise will sometimes escalate to a load rattling as I drive. But it only makes the noise when I have my foot on the accelerator. If I coast the noice goes away. Now the noise sounds like the drive shaft is loose and going to fall out at any minute. I got under the truck and all the U joints are tight. So I’m stumped trying to find the source of the racket. Possible the carrier bearing any ways to check this? Thanks

[geezer#99]

Could be you have a cracked flexplate.
To check the centre bearing just grab it and shake it up/down and side to side. Shouldn’t move much.

[Awann99]

Originally Posted by geezer#99

Could be you have a cracked flexplate.
To check the centre bearing just grab it and shake it up/down and side to side. Shouldn’t move much.

That honestly could be it. I tried to start the truck about a week ago and the starter just scratched the flywheel and wouldn’t start the truck. It’s been having trouble starting with out making a scraping sound.
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[geezer#99]

That would be the solenoid on the starter. Could be weak and not pushing the gear into the flywheel or not retracting.
Check that first.
Clean it up and see if it helps.

[Bigdav160]

I shift my 1969 gmc 1500 into drive it would make a loud ping noise.

That's a classic bad u-joint noise. Do you see any rust around the inside cap area?

[Awann99]

Originally Posted by Bigdav160

That's a classic bad u-joint noise. Do you see any rust around the inside cap area?

I found the source. The carrier bearing bracket somehow completely snapped off of the trailing arm crossmember. It’s just loosely bounding around causing all sorts of racket. Any ideas on how to get the cross member out without pulling the bed?
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[geezer#99]

How much damage is there?
Crossmember is likely riveted on.
Take a pic.

[Steeveedee]

Yes, pics. It may not be necessary to remove the cross member.

[Awann99]

Originally Posted by Steeveedee

Yes, pics. It may not be necessary to remove the cross member.

I did not need to pull the cross member after looking at it closer. But I did have some issues finding a new carrier bearing for the truck. It has the leaf spring 3/4 ton type so I am converting it to the HD style. I made a new thread for the carrier bearing issues. http://67-72chevytrucks.com/vboard/showthread.php?t=791772&goto=newpost
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