Vibration when going over 30MPH

[diegomichel]

Hello guys,

Background:
One day I was driving my jeep and I suddenly hear hell broke down under my jeep. It was the U-Joint that connected the Rear Drive Shaft to the Axle. It was broken and the shaft start hitting stuff there. Had to fix the exhaust and ordered a new U-Joint(Spicer 5-1310X U-Joint Kit) and yoke(Spicer 2-2-1379).

After all that fixed the Jeep developed a constant vibration when going over 30MPH, vibration gets worse if I give more gas, it goes away when I press the clutch. It can be seen on the top of the dashboard.

Things I have done:
Removed the rear shaft and drove it around only with the front shaft, no vibrations at all.
Got tires balanced and an alignment.
When to a shop and the guy checked the tube part of the CV on the lathe and said it was fine.
Reinstalled the rear shaft and vibrations are back.

Video:
In this very moment on the cabin I can feel the vibration. I used the spacer whistle as reference around 4:58.


If you guys can help me to identify the CV shaft that would be good too, I'm thinking on replacing the U-Joints that go on the to the transfer case that would be my next step.

Thank you guys.

 

[Jerry Bransford]

See if the u-joint is centered between the two centering nubs on the yoke. It's easy enough for the u-joint to move out from between them while screwing in the strap screws that mine was a little to the side once which caused a vibration like you describe.

 

[diegomichel]

Hello Jerry,

I just checked and they look fine. The only one that mounts in a similar way(with screws) like the one you describe is the one that goes on the transfer case side. Here are some pictures. That part was not removed the first time I did repairs and the vibration was there.




Here is the u-joint that goes to the yoke on the rear axle:



Thank you.

 

[diegomichel]

Ok is fixed guys, I when to a mechanic and he checked it out... turns out inside the cv shaft knuckle there is a ball-joint? that was getting stuck. He just added a little bit of oil and it works great now. He told me I may need to replace it if it keeps giving me problems.

Bests!.

 

[Jerry Bransford]

Hopefully he greased the CV joint centering ball and didn't just spray it with oil.

 

[diegomichel]

Hi Again,

After a day or two it happened again so I decided to replaced the whole rear Driveshaft with a new one from Adams Driveshaft and still experiencing the exact same thing... I wonder if is the Slip Yoke eliminator or the transmission itself.

Thoughts or things to try?

Thanks.

 

[ac_]

So I agree that it was probably your CV joint in the beginning and since you replaced the whole drive shaft and now it is back, I am inclined to think that maybe you through a wheel weight during the vibration issues you had with a drive shaft? Or possibly do you have a cv joint in the front and am experiencing the same issues you had in the rear?

Run around and see if it looks like you might have thrown a weight on the wheels. Also check the inside of the wheels as I don't know how your wheels are weighted. Or if you just had them balanced maybe they will re-do them for free maybe?

 

[diegomichel]

Hi @ac_

I drove for like a month with the front driveshaft without experiencing the vibrations, that makes me think it isn't the wheel balance.

 

[ac_]

Hi @ac_

I drove for like a month with the front driveshaft without experiencing the vibrations, that makes me think it isn't the wheel balance.

I can only give suggestions. Without driving the vehicle I am kind of at a loss, so the best I can do is stick ideas on your head and hopefully you will trip over the answer. I took my Jeep into Discount tire to get a balance done actually it was the 4th try and on my way back home it started shaking violently from the front end on the freeway and when I got home it was missing all of the weights on the passenger side front wheel. So my point is mine needed a wheel balance on the way home from getting a wheel balance.

If you have replaced your rear driveline, and taken the front driveline out, there isn't much more that can vibrate. Other than what @Jerry Bransford suggested if the ujoints aren't seated correctly.

Originally I was going to suggest that you may have lost a weight on the driveline when it was bouncing around the bottom of the Jeep but you replaced it so that negated that.

I am kind of at a loss of suggestions if it is not your tires, your drivelines, or your alignment. Now you just have to look for weird oddities I think. Sorry I couldn't be more help.

 

[Dawghouse]

Check your spicer yoke. Make sure it is flat on the bottom. If you didn't damage the 8.8 pinion flange when the DS went out. I'm thinking it could be the spicer flange. Just because you got a new one doesn't always mean it's straight and true. Also make sure it is mounted square to the pinion flange. If it is not it will cause you a vib

 

[diegomichel]

Hi guys,

So installed a new driveshaft with yoke balanced together and still having same symptoms. Wondering if it could be the pinion angle. I have done some measurements and it came at +5 degrees. Here is a picture:

Measurements: 23.5 degrees for Drive shaft and 71.5 for pinion flange... with some math I get an angle of 95.

if it was the case, then I wonder how it was working fine before the old DS broke(because there was not vibration).

Bests,
Diego.

 

[Dawghouse]

It almost looks like you have to much pinion angle. Plus add in axle wrap when accelerating it would give you 2* more.

Have you checked your trans mount?

Have you checked the pinion for slop? Pinion bearing could be going bad

 

[JRJONES]

Hi guys,

So installed a new driveshaft with yoke balanced together and still having same symptoms. Wondering if it could be the pinion angle. I have done some measurements and it came at +5 degrees. Here is a picture:

View attachment 49666

Measurements: 23.5 degrees for Drive shaft and 71.5 for pinion flange... with some math I get an angle of 95.

View attachment 49669
View attachment 49670

if it was the case, then I wonder how it was working fine before the old DS broke(because there was not vibration).

Bests,
Diego.

Did you ever figure it out? My 2002 TJ is doing the exact same thing. I was thinking it was the front drive shaft, but after reading the previous comments I am second guessing that thought.

Thanks

 

[DScottBrown]

My 2006 TJ with 4" Rough Country lift and transfer case spacers had an annoying vibration that would also go away with rear drive shaft off. 1 garage had it for 2 weeks and put on slip yoke eliminator and Adams drive shaft. This fixed angle but some vibration was still there. They tried all they could think of including another Adams drive shaft. After a lot of $$$$ I left with my Jeep sill vibrating in steering at 40ish mph and constant in seats at 50-55mph. Drove me crazy. I took it to another garage. They tried Rough Country drive shaft, no change. Then Rough Country slip yoke eliminator. BINGO! It drives like a new Jeep! Now I'm trying to get a refund on the parts from Adams, since there was obviously something going on with the slip yoke eliminator from them. The first garage was in contact with Adams multiple times about this issue. No one ever said hey, lets try a new slip yoke eliminator until the second garage. I hope this helps someone else get to the bottom of an annoying vibration. Wish me luck getting a $530 refund on the parts from Adams.

 

[Goatman]

This is a great thing to get posted. I doubt many would ever suspect the SYE could be the cause of a vibration and be chasing their tail for months or just live with it. Very glad you posted!