The Stovebolt Site Forums The Shop Area Driveline 48 3600 is it the u joints?

Team I have a wobble at about 45 mph a funny vibration starts and fades once I slow down. I am new and not sure where to look first. I have the 2 piece with the enclosed front half and open back,, any ideas? thanks

thanks denny at least im not crazy,,, I do plan to play around with the drive shaft this winter sometime and if I get lucky I will let you know, thanks for taking to time to share. PS I have also gone through the tires and rims and am now on new steel rims with radials .

Have y'all checked driveline angles and u-joint phasing as recommended by the Spicer driveshaft manual found in this tech tip.
http://www.stovebolt.com/techtips/driveline/setup/index.html

Just a guess but perhaps not enough angle on the first shaft, setting the joints in that first shaft out of phase might make a difference... just a guess, read the manual, check the angles, and see if anything looks likely.

Grigg

Two piece drive shaft will shake like crazy if the slip joint is worn. One piece drive shaft will do the same. If you have checked the "U" joints and the carrier bearing I would look at the slip joint for wear. That allows a wobble to set up in the joint itself. That wobble is worse under load so you might not see it with the truck up off the wheels. We just did this on a 57 1/2 ton. Looked at all the other stuff. Wheel bearings, helped did not fix. Yep we did front and rear. New tires, helped did not fix. New shocks, all four, helped but did not fix. Grease gun on every darn zerk we could find...no joy. New "U" joints and a seal for the front yoke, no change. My buddy was not happy about the money spent and I was tired out. Final idea was the slip joint. Lucky for us we have a good shop in town they cut the old joint out and welded a brand new one in then balanced it. Truck is smooth strong and quiet up to 65 which is as far as the owner will push it. Good news is he has clean fluid in the rear and transmission that was really needed. He is now happy and I am out from under that truck. Good luck with yours.

yes its still there,,, you may be right but I think it is the shaft, either u joint or in the middle where front and rear meet,, I read elsewhere here that someone had the same prob and it was the rear shaft and had to have it replaced,, they found a good shaft shop who made a new one. will let you know when it get around to it

steve H I think you pegged it.. that's where I going to look next.. thanks , my 48 came from Utah and had a one owner,,
thanks again

Has anyone checked their flywheel to crankshaft surfaces?

I am interested in knowing how much play is too much in the slip joint spline. Mine has has some but not a lot.