Driveshaft vibration

[1994-5speedk1500]

hey guys new to the forum. I have a 1994 chevy silverado k1500 standard cab short bed with the one peice driveshaft. Its a manual 5 speed with the np241 transfer case. Im having a driveshaft vibration at 60mph. I feel it in the shift lever and the steering wheel so im pretty sure its on the t-case side of the driveshaft. I seen something about using a hose clamp to make-shift balance your driveahaft? Also, i put a lsd 3.42 10 bolt rear from a old gm k20 in it and i heard the rear yoke for the diff is balanced with the driveshaft on the gm's. So since ive replaced my rear is that why its out of balance? Another thing. Ive broke the driveshafts u joints on it and replaced both before i did the rear end and it had the vibration. So i dont think its the rear diff. I was driving when the u joints broke both times

 

[90halfton]

Have you verified the driveshaft is straight? 2 ujoints broke before the rear axle swap? Can't imagine the axle is to blame. Can you feel any drive line slop with it up in the air? Is anything leaking oil? How do the motor mounts look. If it was my deal I would get all the wheels off the ground VERY SECURELY, and run it with somebody in the cab with it running and in gear and listen to all the spinny thingies, I usually use a large prying type screwdriver with my ear against it to listen to things. If the vibration is really that bad it may be evident without the stethoscope tool.
I'm not suggesting you do this if you don't have a safe way of doing this, sh$t can go south if you don't use your head.

 

[90halfton]

Oh. And I'll take a shot in the dark and say a hose clamp won't be involved in the proper fixing of this problem.

 

[1994-5speedk1500]

Oh. And I'll take a shot in the dark and say a hose clamp won't be involved in the proper fixing of this problem.

I believe my u joints are prematurely worn because of a driveshaft vibration, but its my daily and its going to be hard to take the driveshaft out and use someones car to take it to the local driveline shop wait on them to repair it for 3-4 days and then go back and get it. Id just like to be sure it definetly is the shaft. I had new moog u joints put on it about 2 months ago and they have a little play in them inbetween cross and bearing cup. The set that the driveshaft is actually connected to. Not the peice the u joint connect the driveshaft to

 

[1994-5speedk1500]

I believe my u joints are prematurely worn because of a driveshaft vibration, but its my daily and its going to be hard to take the driveshaft out and use someones car to take it to the local driveline shop wait on them to repair it for 3-4 days and then go back and get it. Id just like to be sure it definetly is the shaft. I had new moog u joints put on it about 2 months ago and they have a little play in them inbetween cross and bearing cup. The set that the driveshaft is actually connected to. Not the peice the u joint connect the driveshaft to

Thank u for your reply 90halfton

 

[90halfton]

Thank u for your reply 90halfton

No problem man, any reputable machine/ welding shop should be able to spin your drive shaft for ya and make sure you're in spec. I'm lucky, we've got a shop locally that'll make any size or shape of driveshaft you want, pretty quickly too.

 

[Bob L]

There should be no side play in the joint between the cross and cups. If there is the shaft can spin off center and vibrate. Also make sure the rear u joint is centered in the rear yoke I have seen just a little bit off cause a vibration.

 

[1994-5speedk1500]

There should be no side play in the joint between the cross and cups. If there is the shaft can spin off center and vibrate. Also make sure the rear u joint is centered in the rear yoke I have seen just a little bit off cause a vibration.

I ended up taking the shaft to the local driveline shop. It doesnt necessarily need u joints but i dont want to break a u joint and get another vibration from the shaft falling out. I told them to balance it and put new u joints on so i dont got to worry about anything.

 

[1994-5speedk1500]

I ended up taking the shaft to the local driveline shop. It doesnt necessarily need u joints but i dont want to break a u joint and get another vibration from the shaft falling out. I told them to balance it and put new u joints on so i dont got to worry about anything.

The u joints on it now have just a little play so thats why im getting them switched

 

[Biggershaft96]

Just a thought but do you have the correct Ujoint in the rear? I really doubt the one that is stock for your truck is the correct joint for a k20 rear end. Also how far is your driveshaft sticking out of the Tcase?