"Rattlesnake" noise after changing U-Joint

[Brown Betty]

Hey guys,

This morning I decided to take off my 1-piece driveshaft and change the U-Joints. Under hard acceleration I'll hear a "clunK", so I thought that the U-Joints may be the culprit.

With the driveshaft off the front U-Joint(Tranny) seemed to be in great condition, so I left that one on. The rear one(axle) was stiff, so after fighting with it for over an hour I got the U-Joint changed Now, this new U-Joint is VERY STIFF, but I still put the driveshaft back on the truck.

I took the truck out for a spin to see if the "clunk" was gone, but it was still there And now whenever I accelerate my truck sounds like a rattlesnake Or a Maraca... Your choice

Any ideas guys? I'm guessing it has to do with the U-Joint being very stiff... But I'm stuck there

Thanks,
Darcy

[piecesparts]

My guess is that you have a needle bearing out of position in one of the cups on the u-joint. I may have dropped down while youwere setting the shaft up to be pressed together. that would explain the stiffness and the rattlesnake noise. This will mean disassembly and possibly replacing the u-joint once again.

[Brown Betty]

Originally Posted by piecesparts

My guess is that you have a needle bearing out of position in one of the cups on the u-joint. I may have dropped down while youwere setting the shaft up to be pressed together. that would explain the stiffness and the rattlesnake noise. This will mean disassembly and possibly replacing the u-joint once again.

Hey Piecesparts thanks for the reply.

I don't think a needle is out of place... All the cups seemed to fit in fine.

The U-Joint is tight I think, because the yoke on the driveshaft is bent a little It took so long to get the U-Joint in, because there wasn't enough space for the snap-ring to fit. So I had to pry the yoke apart a bit.

Maybe when the last guy pressed the cups together, the vise bent the yoke a bit

If that's the case I should be looking for another driveshaft, eh?

Thanks,
Darcy

[Vaughn]

If your 1 piece drive shaft goes through the original swingarm crossmember mount, it may be rubbing against the crossmember.

[piecesparts]

If you have a bent issue with the driveline, then take it to a shop that works on them. I have had drivelines rebuilt and straightened at a local place "Drive Train specialties" that has the capability to build or weld new pieces on toa shaft. What I am saying, go somewhere and have it built right, rather than getting another from a salvage yard or ordering on the internet. Where ever there is heavy equipment repair shops then there is a driveline shop somewhere.

As for the rubbing on a crossmember, I am missing that thought and picture.

[jimfulco]

Did you check the joint to make sure it was completely loose (not binding) before you put it in? Sometimes they will bind a bit if the needle bearings can't move freely. A driveshaft guy showed me how to tap the shoulders of the yoke (and the corresponding places on the driveshaft) with a hammer (not too hard, just hard enough to smash your thumb about halfway) a couple of times to free up the bearings before you install the shaft.