Vibration after new u-joints

[hotdog68]

I started to get a squeak in reverse, so I installed new u-joints, Spicer 53207x. I marked everything on the drive shaft before taking it apart and put it back together the same way. Now I have a vibration that starts at 55 and smooths out at 75. The truck was running super smooth even with a bad u-joint.

So, I decided to have the shaft balanced. I took the shaft to Jack Lyons Truck Parts in Miami, FL. They said they would balance the shaft at 2000 rpms which I thought was kind of low. They said that I only needed to balance the tube, and that no one balances the whole drive shaft assembly. The shaft had 8 weights on it from factory. They ADDED a 2 oz weight and said it was balanced. Now I have a total of nine weights on the shaft. Anyway, as I'm driving away, the truck starts vibrating at 30 mph. I go back and complain. I asked why they didn't take the weights off in order to start from scratch. They said that if they take the weights off it will leave a hole in the driveshaft. I told them to grind them off and start over. 2 hours later they said I had 3 holes in the shaft and that I needed a new shaft. $240 later, I'm driving away with the new shaft, and at 55 the truck starts vibrating.

I decided to trouble shoot this thing myself by doing the following:

First, I put the transfer case in neutral put the trans in drive and accelerated slowly to 2500 rpms. No vibration, so I know my converter and trans are good.

Second, I jacked up the rear differential removed the rear wheels and accelerated through the gears, the vibration is still there and at the same speed.

Third, I removed the rear brake rotors and accelerated through the gears. Now the vibration is much less but still pretty harsh at 65

Fourth, I put a camera on the thing that looks like a damper on the front slip yoke and watched. It looked pretty smooth

Fifth, I put the camera on the shaft, and it looks kind of smooth but in some spots its hard to tell if it has some run out.

Last, I put the camera on the rear pinion and it looks smooth.

So I think that I have isolated the problem to the drive shaft assembly. Is there a way to balance the entire drive shaft assembly together? Should I just buy a whole new assembly? Your suggestions are greatly appreciated. Thank you in advance.

 

[seafish]

It is a really GOOD idea after you installing new ujoints, to use a single jack or deadblow hammer to tap (OK go ahead and HIT it!!) the yokes at each new cap to help "set" the ujoints properly. Doing so will relieve any tension pressing on the newly installed cap/ujoints that can and will lead to the new joint NOT spinning freely. You can easily feel the difference by spinning the joint after installing it and then again after hitting it with a the hammer. NOT sayingg that is definitely your problem, but it definitely could be if you didm;t check the joint to hit it with a hammer after p[essing them in.

Also it is possible that you accidentally bent the yoke ears while removing the old ujoints……often the caps are so hard to remove that the press bends the ears in before the caps actually pop (don;t feel bad, very possible/common on these trucks when using a press to remove the ujoints unless special steps are taken to prevent it…don't ask me how I know this…lol). Now, you PROBABLy would have noticed this when it was time to insatll the circlips on the caps, as the cir clips will be hard to install if the ears are bent, but this is not always the case…sometimes you can bend the ears just a little in a parallel to each other and still get the cir clips in, but the shaft will still be binding at the yokes and can/will cause a vibe.

Just a couple ideas…I am sure others will chime in,

 

[RCapehart]

Did you check your carrier bearing? I just went through this. I replaced my carrier and all UV joints in front and rear drive shafts. It helped a lot but I still had a vibration. I had my tires balanced. One was out 13 oz and another was out 7 ozs. But most of the problem was my 17 yr old aftermarket wheels. I replaced the wheels and tires and that took care of it. I have a very smooth ride now!

Ron

 

[hotdog68]

It is a really GOOD idea after you installing new ujoints, to use a single jack or deadblow hammer to tap (OK go ahead and HIT it!!) the yokes at each new cap to help "set" the ujoints properly. Doing so will relieve any tension pressing on the newly installed cap/ujoints that can and will lead to the new joint NOT spinning freely. You can easily feel the difference by spinning the joint after installing it and then again after hitting it with a the hammer. NOT sayingg that is definitely your problem, but it definitely could be if you didm;t check the joint to hit it with a hammer after p[essing them in.

Also it is possible that you accidentally bent the yoke ears while removing the old ujoints……often the caps are so hard to remove that the press bends the ears in before the caps actually pop (don;t feel bad, very possible/common on these trucks when using a press to remove the ujoints unless special steps are taken to prevent it…don't ask me how I know this…lol). Now, you PROBABLy would have noticed this when it was time to insatll the circlips on the caps, as the cir clips will be hard to install if the ears are bent, but this is not always the case…sometimes you can bend the ears just a little in a parallel to each other and still get the cir clips in, but the shaft will still be binding at the yokes and can/will cause a vibe.

Just a couple ideas…I am sure others will chime in,

Thanks for the reply. When I installed the u-joints, I used two 6x6 pieces of wood, a flat punch, and a big ball pein. The ears ended up looking funny on the flange end/rear end of the shaft, but the shop said they were not bent. When they made me a new shaft, they cut the yokes off of the old shaft tube and welded them on to the new tube. The circlips are all in place and I later removed the shaft and checked to make sure that the slip yoke and flange moved freely, no binding, no indexing. I'm in the process of trying to find a shop that will balance the entire assembly, but I don't know if that even exists in South Florida.

 

[hotdog68]

Did you check your carrier bearing? I just went through this. I replaced my carrier and all UV joints in front and rear drive shafts. It helped a lot but I still had a vibration. I had my tires balanced. One was out 13 oz and another was out 7 ozs. But most of the problem was my 17 yr old aftermarket wheels. I replaced the wheels and tires and that took care of it. I have a very smooth ride now!

Ron

Thanks for the reply Ron. I don't have a carrier because I have a single piece drive shaft which comes on the short beds. My front shaft does not spin because I'm using Dynatrac free spins. I know its not my wheels because I jacked up the rear end, removed the rear wheels, accelerated through the gears and the vibration was still there. When you replaced your u-joints, did you have your shaft balanced?

 

[RCapehart]

Thanks for the reply Ron. I don't have a carrier because I have a single piece drive shaft which comes on the short beds. My front shaft does not spin because I'm using Dynatrac free spins. I know its not my wheels because I jacked up the rear end, removed the rear wheels, accelerated through the gears and the vibration was still there. When you replaced your u-joints, did you have your shaft balanced?

I had a drive line shop do it because my knees are giving me problems right now. They charged me $200 + parts and the parts were very reasonable. They said balancing was not needed. They marked everything and put it back the same way it came out.

 

[hotdog68]

UPDATE: Today I purchased an entire drive shaft assembly from the dealer (part #52123122AA) for $430.00. Now the truck runs like the day it was new.