grinding

Has anyone ever got a grinding noise from thier yoke/drive shaft? I have 93 with a RE 3.5 kit and mj shakles. there is no vibes, just gring once and a while.

thanks
buster

Are you sure that the noise is coming from the driveline? When does it make the noise, and can you give a better description of what it sounds like?

Just do what someone who won the Darwin Award did.

Climb under the vehicle and have your buddy drive down the road so you can listen more closely. They found his arm wraped around the drive shaft btw.

And no I hope you don't do it, and yes it is a true story.

Tom Dennis

Why didnt you tell me this before i tried it?:gee:

The grinding happens usally when I let off the gas or at a constant level on it (not accelerating or letting off). I think its coming from the driveshaft/yoke area because thats where the sound seems to come from, while driving inside the car not pulling an indiana jones from underneth. I have no carpet inside, so the sound is easier to pin point.

I was thinking the u-joint was binding or something like that. The sound did not happen with a 2" BB, only after the 3.5" lift.

Thanks
buster

You may not have enough slip yoke engaging the transfer case output shaft. 3" is about the limit, and with the change in angularity caused by the MJ shackles that grinding may be the slip yoke eating up the splines on the output shaft.

I'm not trying to be an alarmist, and this is conjecture, but I can tell you that when a friend went from 3" to 5" of lift, his drive shaft fell out on the road a quarter of a mile from his house. So you're about at the limit. I'd suggest getting under the vehicle (when it is NOT moving!) and have a friend cycle the suspension, maybe jack up the rear by the bumper, to watch how far the slip yoke pulls out from the transfer case. Then figure out where the output shaft ends and determine how much spline length is actually engaged.

I think Eagle is right. I had the sound you describe under the same circumstances and found that with my 4.5" lift, the slip yoke was just barely hanging onto the output shaft of the transfercase. I was sweating every dip in the road (daily driver at the time) until I got a HD SYE and new driveshaft of the correct length under there.

Imagine the front end of your rear driveshaft dropping free while at speed and catching on a lip or pothole in the pavement . . .
you'd either be the first pole-vaulting XJ or a remarkable impression of the cop car from American Graffitti. Not good.

The good news is I didn't find any unusual wear on the output shaft. I imagine the noise was the yoke "slopping around" on the end of the shaft - but I didn't see where it had done damage. I may have just caught it quickly enough.

I'm not suggesting or promoting doing this, but I one time maybe put the whole Jeep on jackstands and let it idle to find noises.


I found a noise, in the front DS, the double cardon joint, even if the two U-joints are ok, there's a "centering yoke" in between them, which has a ball joint and needle bearings. mine were nice and ruined, made a squeeking/clinking noise. now that I fixed that I can clearly hear the wheel bearings....

Another vote for the output/SY engagement. As you let off the gas the output shaft isnt applying torqe to the SY anymore and what little engagement you have is loose enough to "flop" around. Probably the safest thing for you to do is climb under the jeep and grab the Ujoint at at the Tcase side and wiggle it. Try it while the rear end is raised up an inch or two (jackstands or have a friend lift on the bumper) and you're almost garunteed to find some slop.
If you dont have any vibs right now just get a longer DS.

Im starting to agree with the yoke pulling out, there is a about .75" of shiny output shaft when parked and I would assume that it will pull out more with movement.

With no other vibes present, what would the general opinion be about a t-case drop (looking a new crossmember w/ 1" drop) and longer slip yoke like the one from RE? I would think this might give the yoke more shaft to engage without losing the ground clearance or spending all the money for an sye.

Im also gonig to change all the u-joints just for more piece of mind.

thanks
buster

Ditto on the slip yoke. I took my t-case drop spacers out one day just for the heck of it, and whenever i would let off the gas or touch the brakes, I got a grinding noise from that area. (when slowing down or braking, the nose goes down and the rear goes up, pulling the slip yoke out even farther) I put the t-case drop back on, and the noise went away. Long story short, at your lift hieght, if you don't have a t-case drop...get one. If you have one...get a SYE+DS.