Front driveshaft vibes

2001 xj, auto, 32 inch tires

Last year, I regeared to 4.56. (And I swapped a HP dana 30)
I had a vibration that used to start at 75+, and after the regear, it would start at 50. (Faster rpms)

This is a pulsing harmonic vibe, not really affected by throttle. It drones through the entire body.

Long story short, ( 6 months ago)
-I adjusted the pinion angle
-Got a new Tom Woods Driveshaft- Had it rebalanced
-Got the tires balanced/ Swapped them front to rear
-Checked both the tcase yoke and axle yoke torque. (Both to spec)
-Changed the transmission mount

The vibes were better, but just bearable. Still very noisy, and annoying at 65mph. I know I'm not crazy either, on 3.55 gears it was smooth.

Yesterday- I swapped in a newer HP d30, same specs, but new ball joints, hubs, NEW center section bearings, and brand new gears. The axle is perfect, and the gear mesh is right on. All other joints/ parts are new/ in good shape.

Vibes are back. 60 mph, all the interior parts rattle, mirrors shake, and it's just annoying. With more speed, it gets worse. But at 72 mph its smooth?


I raised the pinion, it got worse.
I lowered it slightly (from it's initial position)
It is set at zero degrees. (driveshaft to pinion angle) Still vibes.

And yes, early this year I drove it without the front driveline, and it was smooth.

I could use your help. I'm going on a trip to meet up with some Sierra Chapter guys. One way is 450 miles.

Suggestions?
Thanks- Columbus

If it is OK without the front shaft, it is definitely the front shaft or the angle into the front pinion. Though I would think the HP30 is pretty tolerant for the angle.

Drive to DV without the shaft and put it in at camp. Run DV and Slickrock, take it out and drive home.

I have the same issue.... Front shaft vibes. I just drive around without it now and put it in when I go wheeling. Saving to get Warn hub conversion.

Good luck.

It seems this is an unsolvable issue. I have had lots of vibe issues with mine as well. New parts and fresh driveshaft rebalances have little effect. I am driving around without the front shaft right now.

Yeah. That's the ultimate solution, but theres many places where I like to wheel where I don't want to have to pull the driveshaft, install it, wheel, then pull it back out.

Especially in the snow.

I have exact same issue. Never a complaint on 3.55's but went to 4.10's and noticed it. My front DS is in the garage awaiting a rebuild right now. Do you have the 242 t-case? I've been wondering in the back of my head if it's a t-case front output bearing or something related.

I have had this issue and replaced my t case output bearings to lessen the vibration. I put used ones in and I bet new ones would get rid of the vibe completely.

When's the last time you had your front DS out? I'm having a ton of vibes from mine and when I pulled it I found out it's seized.

Did your output feel loose?

I took the front shaft out, vibes are totally gone.

And I looked at the front most u joint- One of the caps was very gritty.

I pull it off, and sitting within the grease chamber, is a spring.


I don't understand. Its about 1/4 inch long. Is this supposed to be there?
It was sent straight to me from Tom Woods. Gold seal joint.

Yeah same thing when I went to 4:56, so what you need is lockouts! I looked at the warn kit but decided to build a waggy 44 instead.

Wonder if that's the spring that's supposed to be in the ball joint in your CV socket?

whitexj98 said:

Yeah same thing when I went to 4:56, so what you need is lockouts! I looked at the warn kit but decided to build a waggy 44 instead.

Click to expand...

Not even! Been running 6" of lift with a LP D30 for over 10yrs now with my 2000XJ. I dont and never have had any front driveline issues,its still my stock front driveshaft(but I do grease it before every trip).

RCP Phx said:

Not even! Been running 6" of lift with a LP D30 for over 10yrs now with my 2000XJ. I dont and never have had any front driveline issues,its still my stock front driveshaft(but I do grease it before every trip).

Click to expand...

Well then your luckey, what gears are you running? I was able to get them undercontroll, didn't get vibes untill about 70 but my castor sucked so it wandered, so I said hell with it and build an axle with perfect castor and no shafft spinning to even worry about it!

I'm missing that spring in my rear driveshaft centering ball and I have VERY VERY similar vibes to what your describing... I plan on rebuilding the ball by the end of the summer, check the centering ball cus thats the spring that should be right in the middle of it. My needle bearings in the ball are all a dust right now and if your spring is also not in the right spot I'm gona bet yours are also, the bearings being gone is what is allowing vibes.

It is not even close to the size of centering ball spring.

It looks like a pen spring. Random!!

Have you checked to see if the ears on the "new" D30 yoke are stretched out? I just replaced mine with a new one because the front u-joint would become off-center and cause vibrations at highway speeds.

Just my 2 cents...

HTT

if that u-joint is a single joint and it has a zerk fitting that spring is supposed to be putting pressure on the little ball in the zerk fitting

Good point! But the grease fitting seems to be fine, and it's also NOT in the position directly across.
If this is the joint -> +
The spring was found in the north position, and the zerk is in the east position.

How would it bend around the center and make it's way to the other cap?

The D30 yoke is tight. No abnormal wear.

I called Tom Woods, and there's no real answer.

I just pulled the cap off again, and I found a piece of a steel ball wedged in the needle bearings. It's more debris from the zerk.

I'll be following your progress with hopefully an answer.

I just installed a HP Currie 9" with 4.88 gears. Driving was very smooth without the front drive shaft installed. The DS had to be shortened 1" so after picking it up from the DS shop and installing it a rather bad vibration started occuring at speeds above 70mph.

The DS is fairly new and when it was shortened they also balanced it. I'm at a loss as to how to tackle this one. So I'll be following this thread.

Thanks,
Fred
Explorer 1