drive shaft wobble

[Mtbikbob]

I have the currie drive shaft with my sye.
I am hearing a vibration under the jeep at higher speeds, so I jacked up the jeep and turned it on, put it in gear and went looking. My drive shaft where it meets the u joint at the diff is moving up and down. So ok, it appears to be bent where the end of the drive shaft attaches to the U joint. Can I bend this back or is this shaft toast? How do I bend it back if I can?
Thanks in advance,
Bob

[RAT]

I have the currie drive shaft with my sye.
I am hearing a vibration under the jeep at higher speeds, so I jacked up the jeep and turned it on, put it in gear and went looking. My drive shaft where it meets the u joint at the diff is moving up and down. So ok, it appears to be bent where the end of the drive shaft attaches to the U joint. Can I bend this back or is this shaft toast? How do I bend it back if I can?
Thanks in advance,
Bob

Bob,
I have to ask. Are you SURE the yoke is moving up and down? It might just look like it. Any marks on the yoke or shaft that would lead you to think you bent it on a rock? If it is bent, might not be a good idea to try and bend it back. THe shaft can be straightened, and so can the yoke, but the yoke is cast and it doesn't have a good memory. Check the Ujoint to be sure it's not bad. It might be making that look bent. Do you have a mag base and dial indicator? You can check run out on the shaft and the yoke to see which is bent.

Kurt

[Materdaddy]

Bob. If you don't have a magnetic base and dial indicator, I do. Maybe we can investigate this together. Knowing what I know about your jeep, I'm guessing your problem is just pinion angle.

Does the shaft wobble when the Jeep is stopped, and you try moving it all with your hand? If so, it's probably a U-Joint as Kurt suggested.

The reason I think it could be pinion angle is because you have the SYE/CV driveshaft but still have the stock control arms. Your pinion angle was adjusted by 'wollowing' out the stock holes and making your stock control arms work. Maybe they came loose and messed up your pinion angle on your last couple outings. Maybe an angle-finder would be a better tool for you to get so you can check your pinion accurately. If your pinion is off, I'd suggest getting some RE rear upper adjustable control arms. Northridge4x4 is a good place for that. David is a really nice guy! That's where I got mine from (which I haven't installed yet)!

[Mtbikbob]

Bob. If you don't have a magnetic base and dial indicator, I do. Maybe we can investigate this together. Knowing what I know about your jeep, I'm guessing your problem is just pinion angle.

Does the shaft wobble when the Jeep is stopped, and you try moving it all with your hand? If so, it's probably a U-Joint as Kurt suggested.

The reason I think it could be pinion angle is because you have the SYE/CV driveshaft but still have the stock control arms. Your pinion angle was adjusted by 'wollowing' out the stock holes and making your stock control arms work. Maybe they came loose and messed up your pinion angle on your last couple outings. Maybe an angle-finder would be a better tool for you to get so you can check your pinion accurately. If your pinion is off, I'd suggest getting some RE rear upper adjustable control arms. Northridge4x4 is a good place for that. David is a really nice guy! That's where I got mine from (which I haven't installed yet)!

Yes, the stock control arm is 'wollowed out to allow the pinion angle to rotate up to keep the angle within 3 degrees of the shaft. There are no marks on the shaft or nuckle, which is all the more confusing to me. With the jeep standing still, there is no movement in the shaft or ujoints. But place the jeep on blocks, turn it on, put it in gear...hell, I dont need a dial indicator to see the run out on it.
Admittedly, I am missing something here that I am not seeing and I have never taken one of these apart. It looks like the whole CV has to come off with the drive shaft or do you just punch out the ujoint?

[Materdaddy]

Yes, the stock control arm is 'wollowed out to allow the pinion angle to rotate up to keep the angle within 3 degrees of the shaft. There are no marks on the shaft or nuckle, which is all the more confusing to me. With the jeep standing still, there is no movement in the shaft or ujoints. But place the jeep on blocks, turn it on, put it in gear...hell, I dont need a dial indicator to see the run out on it.
Admittedly, I am missing something here that I am not seeing and I have never taken one of these apart. It looks like the whole CV has to come off with the drive shaft or do you just punch out the ujoint?

The CV comes off w/ the shaft. Just pull the whole shaft and take it to a driveline shop to have it balanced maybe?

[Mtbikbob]

I am going to assume the driveshaft is bent somewhere. So I am going to take it to a driveline specialist. But my question is, when it is installed in the jeep it only has about 1 1/2 inches into the receiver part of the shaft. Is that enough?

[peteyg]

Yes, that's plenty, and your problem is more likely a bad u-joint than a bent driveshaft. That centering ball in the middle of the CV can wear out, too (this would be my first guess). Also, it is very common to get slop in the splines of the slip yoke. The driveline shop will be able to tell you for sure.

Also, now that the shaft is out, give the pinion yoke a good shake and make sure it isn't loose. If it is, use a 1 1/8" socket and torque that puppy down to about 200 pounds (if you don't have a torque wrench, that's about as hard as you can pull it with a 2' breaker bar and maybe a 2' cheater). If it's STILL loose, then the gears need to be reset.

[Materdaddy]

Yes, that's plenty, and your problem is more likely a bad u-joint than a bent driveshaft. That centering ball in the middle of the CV can wear out, too (this would be my first guess). Also, it is very common to get slop in the splines of the slip yoke. The driveline shop will be able to tell you for sure.

Also, now that the shaft is out, give the pinion yoke a good shake and make sure it isn't loose. If it is, use a 1 1/8" socket and torque that puppy down to about 200 pounds (if you don't have a torque wrench, that's about as hard as you can pull it with a 2' breaker bar and maybe a 2' cheater). If it's STILL loose, then the gears need to be reset.

"There you have it and there it is."

[Mtbikbob]

"There you have it and there it is."

You funny guy.... my own quote against me.

Anyway, as you can almost see by looking at the driveshaft, all these parts are just about new. The driveshaft, CV were new last January. There was no slop of movement at the C.V. nor at the pinion. The most wobble appeared to be on the shaft closer to the connection point between the shaft and the u joint to the pinion.
Maybe just get another one...hold this one for spare?
cheers :cocktail:

Bob

[peteyg]

You funny guy.... my own quote against me.

Anyway, as you can almost see by looking at the driveshaft, all these parts are just about new. The driveshaft, CV were new last January. There was no slop of movement at the C.V. nor at the pinion. The most wobble appeared to be on the shaft closer to the connection point between the shaft and the u joint to the pinion.
Maybe just get another one...hold this one for spare?
cheers :cocktail:

Bob

New doesn't really mean anything. THIS was a brand new u-joint not 4 trips ago:



Admittedly, this was caused by a bad driveshaft angle and insufficient reinforcement for my anti-wrap bar. Still, just saying it's new doesn't make it good. Something to think about.

U-joints are easy to replace, and as long as the rest of the driveshaft is ok, it's no big deal to just put a new one in there and be on your way. And don't discount slop in the slip yoke. Although, in that case your only real option is to replace the entire driveshaft if you can't live with the vibes.

[Materdaddy]

You funny guy.... my own quote against me.

Anyway, as you can almost see by looking at the driveshaft, all these parts are just about new. The driveshaft, CV were new last January. There was no slop of movement at the C.V. nor at the pinion. The most wobble appeared to be on the shaft closer to the connection point between the shaft and the u joint to the pinion.
Maybe just get another one...hold this one for spare?
cheers :cocktail:

Bob

I'd think you'll still want to find out if that's your problem. I'm sure a driveline shop can see if that shaft is off-balance for cheap and in no time at all. You don't want to drop a couple hundred on a new shaft if that's not your problem! (Although spares can't hurt!)

[Mtbikbob]

thanks Pete, Mat for your input. I'll post up after is diagnosed. Mat, it you got the time and still have the driveshaft with C.V., waiting to be installed in your jeep, maybe bring it over and we'll install it into my jeep and spin the wheels while on jack stands. I would love to see what the difference would be. Also if there was something other than the drive shaft problem, it would show up again. In either case, my driveshaft is at Oceanside Driveline specialists and I am waiting to hear back from them. I gave them the whole shaft with the C.V. still attached. I am assumeing they can inspect the C.V. along with the shaft.

Thanks again,
BobO

[peteyg]

Just one more note:

The absolute BEST driveline shop in this region is Driveline Service of San Diego on Morena Blvd down by the intersection of I-8 and I-5. They know Jeeps and Jeepers. I know this doesn't help now, but the next time you need something done, keep them in mind.

[Materdaddy]

thanks Pete, Mat for your input. I'll post up after is diagnosed. Mat, it you got the time and still have the driveshaft with C.V., waiting to be installed in your jeep, maybe bring it over and we'll install it into my jeep and spin the wheels while on jack stands. I would love to see what the difference would be. Also if there was something other than the drive shaft problem, it would show up again. In either case, my driveshaft is at Oceanside Driveline specialists and I am waiting to hear back from them. I gave them the whole shaft with the C.V. still attached. I am assumeing they can inspect the C.V. along with the shaft.

Thanks again,
BobO

You're only a couple miles from my condo at Oceanside Driveline! I do still have my shaft w/ CV that's brand new in the box! If you don't have an answer by this weekend, maybe I can bring it over. It's still sitting in the box in my office!!!

[Mtbikbob]

Just one more note:

The absolute BEST driveline shop in this region is Driveline Service of San Diego on Morena Blvd down by the intersection of I-8 and I-5. They know Jeeps and Jeepers. I know this doesn't help now, but the next time you need something done, keep them in mind.

I will,
Many thanks,
Bob