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U-joint?

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jhorton3

jhorton3

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For the past few weeks I've had a "clunk" emitting from the back end of the car. It happens if I'm accelerating from 2nd through 4th. Tonight I put the car up on jack stands and wiggled things around, checked the differential for gear oil (which it has plenty of). I grabbed the driveshaft and wiggled it around, and I heard a similar noise. I can see that the u-joint rocks back and forth quite a bit. Not sure what an acceptable tolerance is for play.

How difficult is it to replace the u-joint from under the car while the driveshaft is still attached to the transmission side?
 
pulling a drive shaft is about as easy as a job gets.. its putting it back on that can be a pain, but,... ..if you wrap the front U-joint with masking tape it'll be stiff enough to slide right back on, no drama... so go ahead, unbolt it from the diffy and get it fixed... (the masking tape will fly off all by itself once you get to goin'.
 
A spin around the block leads me to believe that the front u-joint is even worse. I got on a straight and did a jerk test. The back one clunked, but the front one sounds really bad. So I guess the whole driveshaft will be coming out.

I found John Twist's 5 minutes u-joint replacement video on YouTube. I don't think I even want to try and compete with that, but if I can get it completed in an afternoon I'll be doing well.
 
I don't know your mechanical skill level, or willingness to attempt things, BUT its REALLY CHEAP just to take it down to a driveline shop and not have to mess around. I took mine in to have it balanced and a u joint replaced. the rear holes were SHOT! I have a 5 speed, so i didn't want to have to change over the front as well so i took in a spare driveline and they made one out of two, put in a new universal, balanced the assembly and charged me $85 including parts!..... ..

Wow, not even worth messing with for that!
 
Just about any real shop can replace universals. Machine shops as well. Call around and price em.
 
It is an easy-enough job to do yourself, but a "real" shop will also make sure that the shaft is balanced as well as refurbished!!! :wink:
 
Balanced?? How fast we going here.
 
Jack, no matter what speed, an out-of-balance drive shaft will at the least be annoying!!! (hate to think about the "at worst"!). It is a simple spin-balance operation that will cure occilations that will transfer to the axle and the tranny!!!
 
Hmmm, have never done that. Bet there is no one in this neck of the woods that does it. Heck. we don't even have a machine shop.
 
I know how I'll be spending my Saturday now. I'll pick up some spicer replacements and pull the shaft tomorrow afternoon. Hopefully I'll have it back in tomorrow night.
 
Balancing the driveshaft eliminates the need to index the shaft to the pinion. No matter how you mount it it will run smooth. In one instance (a 1973 Ford Torino), having the driveshaft balanced reduced overall noise at freeway speeds. It's something that I have done several times, but it is an extra expense.

When I have a shaft shortened I also have it spin balanced.

I did not balance the Midget driveshaft when I replaced the rear U-joint recently. At the same time I also replaced the rear chunk. A test drive produced vibrations. I rotated the driveshaft 180 degrees with respect to the pinion and it smoothed out.
 
Yes, I would have it balanced if I cut it of course.

See no need when replaceing the u joints. Just get it back on the way it came off.
 
Jes did the u joints on mine a week ago. (If you use the greasable type be sure to face the zerk fitting outwards of the center of the driveshaft) Look closely the ends have a small relief in them to accomadate the zerk fitting. (I had to point this out to my mechanic after he put them in wrong and than help him flip the right way.)
 
Isn't it amazing how little experience mechanics have today. It seems they know very little about fixing things and most about replaceing things.
 
I have several "mechanics" that work for me and the standard practice for most has become... Replace replace replace until you get it right! Makes it very hard to make money that way. (when your honest enough to only charge people for the problem) Im sure there are others out there that charge you for there own guessing work. We just dont do that.
 
Scott, you are to be commended. Not many places like that anymore.
 
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