help ! problem of transmission...UPDATE: SOLVED

Topan · **Posted:** Sat Jan 28, 2012 11:57 am

My 2005 KJ has just passed the 100 kmiles. Since 2 days i noticed some strong vibration at about 40 miles per hr, only decelerating. Driving up to ski in the mountain, the vibrations got worst. Now the vibs are very strong even when accelerating and decelerating as well , to the point that the driving wheel is vibrating.... And we are stock in Zermatt...just kidding. What could be ? Woabled disk ? The X shape nut in transmission arm ?... Thanks...

papaindigo · **Posted:** Sat Jan 28, 2012 12:41 pm

"Driving wheel" = steering wheel? If so could be any of a host of things in the front end. Tire tread separation, shocks, brakes, wheel balance, tie rods, alignment, wheel bearings, etc. I know it sounds stupid but could be a chunk of ice hanging on the front suspension. If it was mine I'd drop by my local independent general mechanic/tire place and have the front end looked at.

Topan · **Posted:** Sat Jan 28, 2012 1:17 pm

The vibrations are coming clearly from the rear...

papaindigo · **Posted:** Sat Jan 28, 2012 2:19 pm

Ok then I presume we can eliminate steering related items. Could be bad "U" joint(s) in the drive shaft, distinct from front end CV joints; sticking drive shaft slip joint; rear end tire, shock or brake related items; or possibly the big somewhat "V" shaped rear upper control arm or lower control arms. I'd look at these external thing before thinking transmission, rear differential or bearings.

Glend · **Posted:** Sat Jan 28, 2012 4:15 pm

Start with the U-joints on the tailshaft, mine were replaced recently and the shaft rebalanced and now it is very smooth with no take up slack or vibration.

Topan · **Posted:** Sun Jan 29, 2012 5:05 am

Yes, I just placed the order for a stock U joint. (This is the metal part with a cross shape , correct? ) anyone like JeepbyAl is making a strong than stock version ?
Thanks Glend.

Joe Romas · **Posted:** Sun Jan 29, 2012 11:14 am

Topan wrote:

. (This is the metal part with a cross shape , correct? ) anyone like JeepbyAl is making a strong than stock version ?
Thanks Glend.

YES, it sounds like the correct part. While you have the drive shaft out it would be a good idea and common practice and not that much more work to replace both U joints on the shaft.

There are greaseable ones available but I've the holes drilled in each of the 4 legs for the grease actually weakens them.
So a good quality aftermarket should be fine. But if I read it correctly you've gotten 100k miles out of the originals. That's not bad :SOMBRERO:

Of all the U joints I've replaced over the years about half were worn out and half were rusted. But were the rusted ones a result of them being worn out, who knows :?:

Topan · **Posted:** Tue Jan 31, 2012 3:55 am

Joe Romas wrote:

Topan wrote:

. (This is the metal part with a cross shape , correct? ) anyone like JeepbyAl is making a strong than stock version ?
Thanks Glend.

YES, it sounds like the correct part. While you have the drive shaft out it would be a good idea and common practice and not that much more work to replace both U joints on the shaft.

There are greaseable ones available but I've the holes drilled in each of the 4 legs for the grease actually weakens them.
So a good quality aftermarket should be fine. But if I read it correctly you've gotten 100k miles out of the originals. That's not bad :SOMBRERO:

Of all the U joints I've replaced over the years about half were worn out and half were rusted. But were the rusted ones a result of them being worn out, who knows :?:

i placed an order for the rear U-joiint, but will gladely replace the front one as well.
Do you have the parts nber ? I am bit confused on what goes where... and could not find the joints on the parts diagrams on the wholesalesmopar... thanks !!

Topan · **Posted:** Wed Feb 15, 2012 3:53 pm

wow. things are getting complicated.
We lifted the Libbie and checked the shaft, absolutely no slack in the rotation. When turning it manually , there is no slack at all.... should I exclude the U-joint? i got them (front and rear) so I could replace them, if needed.

Now when driving back from the office tonight, i concentrated on the noise and vibes: the worst is at 50mph with almost no throttle, at that pace there is a very deep wobling noise/vibe.
I am thinking of the mounting shock of the engine ????
or the exhaust, which has been badly hamered during some off-road trips.... could it be that the exhaust is a kind of out of place and vibrating? defintely the truck is more noisy when driving, but in neutral and reving, there is no whole-in-exhaust-noise ...strange...
i am lost ....
i will put my new GoPro under neath the libby to see if i can detect something vibrating: shaft, exhaust....

CATCRD · **Posted:** Thu Feb 16, 2012 12:15 am

Topan wrote:

wow. things are getting complicated.
We lifted the Libbie and checked the shaft, absolutely no slack in the rotation. When turning it manually , there is no slack at all.... should I exclude the U-joint? i got them (front and rear) so I could replace them, if needed.

There doesn't have to be slack in the joints for them to be bad. Mine had no slack, but when I took the driveshaft off, one axis was nearly seized, and the others were free. Replacing both the joints solved the problem.

Topan · **Posted:** Sun Feb 26, 2012 2:03 pm

Hi,
CATRD you were right !
I have had replaced both U-joints on the rear shaft and the vibrations are gone !!! :pepper:

Here are some pics of the u-joints, the rear one had 2 axles completely rusted while the other axles are worn out but nicely polished:

And when removing the rust, the axle appears to be all dented by the small rolling bars:

Thanks !

help ! problem of transmission...UPDATE: SOLVED

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