JKbrick
Active Member
Curious how you measure this. In my head I think the angle of the driveshaft and the face of the yoke should be a right angle? How do you get yours dead on?
Rear Driveshaft vibes
- Thread starter Speedy_RCW
- Start date
Curious how you measure this. In my head I think the angle of the driveshaft and the face of the yoke should be a right angle? How do you get yours dead on?
The pinion should be in line with the drive shaft. Not sure what you mean by the "face" of the yoke but if you're referring to the where the u-bolts or straps get attached to, yes, that should be at a right angle to the drive shaft.
JeepFan
Hooked
As Eddie mentioned, my vibration was ultimately caused by excessive runout at the pinion yoke. Up to that point I installed different drive shafts, rebalanced the drive shafts multiple times, changed pinion angles multiple times but, the vibration never changed.
I actually figured out what it was by accident. I recently had the rear wheels off the ground so I could check for a bent axle flange. With the wheels off the ground and the engine running, I put the Jeep in drive to spin the wheels. First, I noticed my right rear axle flange was definitely bent. Then, I happened to notice that as the drive shaft was spinning, I could actually see it moving up and down slightly at the pinion flange. Suspecting this can't be right, I had a shop check the run out with a dial indicator to verify what I was seeing. Turned out the run out measured over 40 thousandths of an inch. The spec is 0!
Had a new yoke installed and voila, no more vibration.
I hope you get it solved soon. I put up with it far too long!
Speedy_RCW
Hooked
Wow that's a lot! Glad you got it figured out. I've had the vibe with stock shaft and flanges and now same vibe with aftermarket shaft and the new flange and yoke that came with it. I set pinion angle tonight so I'll see if it's any help on the way to work tomorrow morning. I've seen a lot of threads on the Googler with this same issue but no one ever says what the remedy was or if there ever was one. Maddening though.
JeepFan
Hooked
I seriously doubt your pinion angle will have any effect on the vibration. It might be worth spinning the drive shaft with the wheels off the ground to see if it's running true. If you see any vertical movement in the shaft, there's your problem. Good luck and please keep us posted.
I agree with this 100%. The only time I've seen pinion angle be an issue is if the control arm bushings or joints are bad and they allow for a significant amount of axle wrap/pinion lift.
Speedy_RCW
Hooked
I'll try spinning the tires off the ground and see what I find there as well. Thanks for the tip. After adjusting pinion angle there was a slight improvement in the vibration. Dropped the Jeep off today to have the tires balanced just in case. I've had a little bit of a balance problem since I put the tires and wheels on which was right around the same speed I'm getting the worst of the vibration since the regear. Thinking I'd rule that out just in case there was some sort of resonance between the tires being out of balance compounding the issue or some sort of other scientific shit going on. :idontknow: But it can't hurt to do it and its cheap and easy.
So I have plenty of other things to check after this. Has anyone had an issues with the transmission mount causing problems? I only have 16k on the Jeep so mines not worn out or anything but thought I'd ask. I know poly mounts usually end up causing more felt vibration. Just another thing I'm pondering. I'm sure this is going to be a long process but I'm bound and determined to figure it out. I appreciate your guys input.
Speedy_RCW
Hooked
Okay, so I'm back to diggin into this vibration a little deeper. Been traveling and woking on the house so Jeep has been in a holding pattern. But I've determined that the vibration is a combination of both shafts. For the time being I'm leaving the front shaft out completely and solely focusing on the rear. With just the rear shaft in the vibe isn't as bad but still there. I've checked the pinion and transfer case output are running true. Checked torque on TC output. Checked for any play in TC output and pinion bearing. Ran the jeep on jackstands and looked underneath. Didn't see anything but I'm also not going to run it up to 50mph sitting on jack stands. So I took the shaft to a local driveshaft shop to have balance checked. He had me mark where the slip is sitting at ride height before removing. First thing he tells me is the shaft is about 1.5" too short. I'm no expert on driveshafts so I asked if that difference in spline engagement could be causing the vibration. Basically what we discussed was, if I'm trying to rule out the driveshaft we need to make sure its right. So he's going to re-tube and balance the rear shaft. Front shaft is good length so I'm having him check balance on the front too while he's at it. So I hate throwing money at it but fingers crossed I get some improvement. Shaft should be done Monday or Tuesday so I'll update after I take the Jeep out for a test drive. Once (or if) I get the rear running smooth I'll move my attention to the front.
Jeepfan30
Member
I have been following this thread because I have had a mild vibration only noticeable at 50mph. After reading this whole thread I went out this morning and watched my rear DS spin. I observed some wobble at the TC flange. I unbolted the DS at the TC and put the jeep in gear and still observed wobble. I then pulled the yoke off and put the jeep in gear, didn't see any wobble. Put the yoke back on and observed wobble.
Where is a good place to get a new TC yoke? I have a 1310 Coast rear DS with aftermarket yokes. Thanks,
Where is a good place to get a new TC yoke? I have a 1310 Coast rear DS with aftermarket yokes. Thanks,
Speedy_RCW
Hooked
I'm sure you could call up coast and get a replacement yoke.
JKbrick
Active Member
Let me look but I think I have one I can send you
Jeepfan30
Member
Oh man, that would be awesome. Thanks
Speedy_RCW
Hooked
I just posted up about why I joined WAL and this just reaffirms why. :thumb:
Jeepfan30
Member
Exactly what I was thinking, pretty amazing place.
JKbrick
Active Member
Jeepfan30
Member
It looks like it would work, what did it come off? As long as it fits a JK transfer case and 1310 u-joint it should work. Thanks! I'll send you a PM.
JKbrick
Active Member
I bought used driveshafts from Arizona and nmwranglerx , both members here. I don't remember which one said he was having troubles getting the yokes off so I purchased new ones and had them on when the shaft showed up. It came with this yoke, I just soaked it in evapo rust and painted it so it wouldn't rust on a shelf in the garage. I replied to your pm before I saw this
Jeepfan30
Member
Great, thanks! I really appreciate the generosity and the time out of your day to ship this to me. Members like you make Wayalife the great community that it is. Be sure to include a good return address, you are the type of person I would send a Christmas card to:thumb:
JKbrick
Active Member
Your very welcome, I'm leaving the office now for town and will get it mailed.
Jeepfan30
Member
Got the package today, thank you:rock::thumb: