another possible drive line vibe question

desertrunner

Active Member
Good luck. Hope you get it figured out. Oh, to answer your original question, I believe it was the pinion bearing that went first which caused the pinion to start eating itself.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
Gottcha
How bad would you say the vibrations were?
Mine aren't bad but just enough to be noticeable. I would describe it like 1/10th of what it's like when you start touching the rumble strip on the side of the highway.

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BaddestCross

Active Member
Gottcha
How bad would you say the vibrations were?
Mine aren't bad but just enough to be noticeable. I would describe it like 1/10th of what it's like when you start touching the rumble strip on the side of the highway.

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It didn't start out too bad and it wasn't noticable until about 70mph. It did get progressively worse until something totally blew out at around 1500 miles or so.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
 

desertrunner

Active Member
It didn't start out too bad and it wasn't noticable until about 70mph. It did get progressively worse until something totally blew out at around 1500 miles or so.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
Ok well I'll keep going with my plan to fix the front first then remove the rear shaft and see what it does. I'm at about 500 miles on the new gears so the last thing I want to to be driving down the highway on a ticking time bomb

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desertrunner

Active Member
just for future reference if id does turn out to be some bad bearings in the rear diff, as long as i keep all the shims in order and get my hands on a press i should be able to replace the bearings myself right? there isnt anything that will change in the gear set up with just changing out the bearings?
 

BaddestCross

Active Member
just for future reference if id does turn out to be some bad bearings in the rear diff, as long as i keep all the shims in order and get my hands on a press i should be able to replace the bearings myself right? there isnt anything that will change in the gear set up with just changing out the bearings?

Anyone ever tackle a bearing replacement themselves?
I feel like it can't be hard if you don't have to mess with gear set up

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Sorry man, I wish I could help... It may have been that the shims weren't right in the first place or it could've been shitty bearings. I was supposed to get Timkin bearings with the package I bought but they ended up being some other brand (don't remember the name). Apparently it was the same brand the factory uses now, but my guy said that he's even seen bearing failures in new JKs with these in them. The replacements sent were the Timkins that were supposed to have been there from the jump.

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
 

desertrunner

Active Member
Ok little update to this thread. Getting the front dialed in seemed to help a little. Not really feeling that vibe I had at 45 anymore which is awesome. Now the one I'm still working on is the high speed one.

Between 55-75 When I'm on the gas I'm getting an audible bass that is on for 1sec off for 1sec. (Kinda like right when you start to touch the rumble strip on the highway) when I get off the gas that audible vibe goes away but still have the little tickle in the floor.

I guess my next step is to pull the rear shaft and see if that changes anything. But anyone have any thoughts?

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desertrunner

Active Member
So more data for this as I move to the rear. Just as a had with the front i have all stock rear control arms. My rear pinion and drive shaft are about 4* off as shown in the picture below. I know those should be as in line as possible. Could that be causing that vibe I'm feeling at high speeds?

I feel like it's not related because it was set like that before the re gear and the vibe wasn't there but now that everything is moving faster maybe that is the cause?

20180408_143418.jpg

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BaddestCross

Active Member
So more data for this as I move to the rear. Just as a had with the front i have all stock rear control arms. My rear pinion and drive shaft are about 4* off as shown in the picture below. I know those should be as in line as possible. Could that be causing that vibe I'm feeling at high speeds?

I feel like it's not related because it was set like that before the re gear and the vibe wasn't there but now that everything is moving faster maybe that is the cause?

View attachment 298696

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You still have the stock driveshaft? Is there grease slung out on the gas tank?

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Build Thread - Adventures of Fiona - https://wayalife.com/showthread.php?t=47407
 

desertrunner

Active Member
Well good news! With the rear shaft pulled the vibe is 100% gone. So something in my rear drive line is causing it. Now the question becomes what the hell is it?

Could the 4* angle on the rear drive shaft cause the vibe?

Maybe a drive shaft out of ballenece.

Rear diff bearings?

Not too sure where to start

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desertrunner

Active Member
Would getting it "balleneced" be inexpensive?
Not too sure I have never had a shaft balanced. But I imagine it would be cheaper than buying new arms to correct the pinion angle or having the rear diff looked at so that's probably my starting guess.

I want to do some research or see of someone else will chime in with what might be the cause of that 1 to 1 vibration at 55-75 mph though.

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desertrunner

Active Member
Damn well the only guy in town that does drive shaft ballance wants $60 to check it and if it does need any work then it's about $150 total. I feel like I could buy a new oem replacement or find a used one for less than that....

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desertrunner

Active Member
I guess I could pay the guy the $60 to spin it and see if it is balanced and if it checks out then I know that's not the problem. I just figured it would be cheaper than that to get it spun to check the balance

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DWiggles

Caught the Bug
Damn well the only guy in town that does drive shaft ballance wants $60 to check it and if it does need any work then it's about $150 total. I feel like I could buy a new oem replacement or find a used one for less than that....

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My rear JE REEL 1350 is at the drivetrain shop as I type this, they are going to retube it, replace the CV between the Double U-joint on the Transfercase side, THEN balance it... for just shy of $300 :doh:

I'ed HAPPILY pay the $60... :twocents:
 

fiend

Caught the Bug
Well good news! With the rear shaft pulled the vibe is 100% gone. So something in my rear drive line is causing it. Now the question becomes what the hell is it?

Could the 4* angle on the rear drive shaft cause the vibe?

Maybe a drive shaft out of ballenece.

Rear diff bearings?

Not too sure where to start

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Grab the rear pinion flange and see if it or the pinion itself is loose.
 

DWiggles

Caught the Bug
Well good news! With the rear shaft pulled the vibe is 100% gone. So something in my rear drive line is causing it. Now the question becomes what the hell is it?

Could the 4* angle on the rear drive shaft cause the vibe?

Maybe a drive shaft out of ballenece.

Rear diff bearings?

Not too sure where to start

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Its MOST likely the driveline itself if nothing else has changed.

But 4° (Hold Alt while typing 0176) ;) COULD cause a vibration. generally, 1°-2° between the driveline and pinion is what is recommended. but again, if this isnt a new pinion angle, I think if the angle was the problem, you would have had the vibration all along.

If its the rear diff bearings, the sound/vibe would likely still be present when you drive, that wouldn't go away just because the shaft was pulled... everything still rotates.
 
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desertrunner

Active Member
Grab the rear pinion flange and see if it or the pinion itself is loose.
I did check the pinion when I pulled the shaft and it seemed to me (in my limited knowledge) that it's all good but I will check it again. The little torque paint they put on the pinion nut hasn't slipped either.
Its MOST likely the driveline itself if nothing else has changed.

But 4° (Hold Alt while typing 0176) ;) COULD cause a vibration. generally, 1°-2° between the driveline and pinion is what is recommended. but again, if this isnt a new pinion angle, I think if the angle was the problem, you would have had the vibration all along.

If its the rear diff bearings, the sound/vibe would likely still be present when you drive, that wouldn't go away just because the shaft was pulled... everything still rotates.
Yeah so litteraly the only thing that changed was the re gear.... since its the stock driveshaft and not a U joint shaft I was thinking that 4* wouldn't be too bad but now that the shaft is spinning even faster with the new gears maybe it is. Thats kinda what drew me to think out of balance shaft if it was ever so slightly out of balance and now it's spinning faster it's causing the vibe.

As far as the bearings go if they were bad I also thought that I would feel it even with the shaft out since the diff is still spinning, and the vibe is 100% gone with the shaft out.

Long story short if the shaft checks out good then I'll fix the pinion angle and hope that works. If that doesn't work Idk what I'll do yet

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desertrunner

Active Member
So the drive line guy in town said he can't spin the stock shaft. His equipment doesn't hold that style shaft and he said he doesn't know of anyone near me that can.

So still spitballing ideas here knowing that I did not have the vibe before the re gear. The shaft is the same the pinion angle is the same so assuming that isn't the issue, my thought is something in the rear diff. When I pull the rear shaft the vibration is gone so I can only imagine it has something to do with load on the diff and on the drive side of the gears.

I guess I can pop the rear cover again and check the tread pattern on the gears and make sure it was set up correctly in the first place?

I also could pull the carrier and spin the bearings on the carrier and pinion and see if anything is obviously messed up with the bearings?

One issue I'm seeing with pulling the carrier is the idiots that did my re gear routed the locker line right in front of the ring gear instead of over the top so I kinda risk popping a hole in that line by bending it more.... edit I'm dumb that line should come out with the carrier if I pull it....
20180312_190214.jpg

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