shudders at 70

[68gmsee]

Originally Posted by acl

OK so far tires and wheels balanced and checked twice. Drive shaft balanced and still have the shudder. Today going to measure and laser drive line for alignment, Am still looking for other imput. Thanks for the help so far. Gary

As I mentioned and others have said, it's still possible you have a bad tire. If you're postively sure it's not the drive line (joints, angle, etc.) I'd still go with rotating them front to rear if you can. Of course this assuming you have the same size tires all around.

The one that I fought for months, was balanced and checked at least 2 times. I finally got some different brand tires and problem went away.

Keep us posted.

[Boog]

It would be great if you can find a tire shop that can spin balance the tires ON the truck. That could help narrow it down. Some people like that kind of balance as it balances the tire, wheel, rotor and hub as one.

[Blazer1970]

I would try to find a complete set of tires that you could swap onto the truck for a trial or swap them out one at a time with a spare or any known good tire.

[DA68]

Gary - have you figured this out yet?

[Old Chevy Mech]

Jack up the rear of the truck real solid. Start the engine, put her in gear so the rear tires spin. Look at the rims and see if any are bent. Your initial post said a shutter, so if I had a shutter, which I did recently, it was a bent rim.
If you have an assistant, have them rev it until you see if the rear starts moving in any bad way. If you get nothing, then I'd check the front rims and see if one of them is bent.

Frank

[acl]

Sorry it took so long, but after everything else i changed the flywheel and that fixed the problem. Did not look bad but changing it did fix the problem . Thanks for all the input and maybe this can help someone else. Gary