Hello, I am in need of help. I am the proud owner of a 1994 Jeep Cherokee Sport I have had my XJ for 14 years and she is my pride and joy. A couple years ago I had to have the rear end rebuilt. Everything has been fine until the last year or so. I have a thumping noise going on when I am going down the road. My XJ has a 3" lift when the noise started I took it back to the shop that fixed the rear end and was told the noise was caused from the lift and axel articulation. The U-Joint were supposedly hitting when going down the road. We replaced all u-Joints because most of them needed to be replaced and the shop put an extended yolk on to help with the issue. Well the thumping seem to stop for a short time. I took it to a jeep dealership and they put it on a lift and ran it. They put a stethoscope up to the transfer case and could hear the thump as the wheels turned. They did not listen to the rear end with the stethoscope they think but are not sure that it is coming from the transfer case I swear it is coming from the rear end. I need help right now my Jeep is my only transportation and I am afraid I am going to cause major damage. Any advice is greatly appreciated.

 

weird...one would think an extended yoke would worsen the problem. The shorter the distance between the tranny and the diff (without rotating the diff) the greater the angle on the u-joints. Thats why people use drops (decrease angle by effectively lowering output shaft) and SYEs or hack-n-tap (increase distance).

 

Sorry I missed a word it is an EXTENDED range yolk

 

ya, i don't think that would help any. I googled "extended yoke", couldn't find shyt but i'm guessing all that is is a yoke with a deeper spline?? It'll give more support between the output shaft on the t/c and the drive shaft (as the lift has pulled the yoke away from the t/c somewhat) but it won't change your angles. If the u-joints were hitting before chances are they are again.
Running it on a hoist as well will just make it worse. The body (and with it the t/c) rises on the hoist and the diff drops increasing angles even more drastically.

 

Look into a SYE (Slip Yoke Eliminator) I need one but they're like 300 bucks which is not in my budget right now. I have a two inch lift and am experiencing am issue. Your xj thumps at 45+ mph going down the road right?

 

My paper work say's it is a GM T350 slip yolk and the repairman said it had a greater range of movement then what I had before. If the U-Joints are hitting would I be Able to see the abrasions? I have crawled under and can see no signs of any thing hitting.

 

It use to thump at 45 mph but now it is ALL the time. It does not matter if I am costing or giving it gas. I am looking into the SYE right now thank you.

 

I'm hoping someone more experienced with this would hop on this thread but I'm not sure what the shop did as far as the extended yoke but from what I've read on here the t case drop is good for a temp solution for 3.5 inches of lift or greater until you can budget in a SYE. Also, the other threads didn't mention the extended yoke your shop put on. I'm interested in what it is.

 

Good, look into the SYE it apparently solves the problem, I think you may also need a different rear driveshaft. Def do a search on here for SYE or google "SYE xj" I know there is a thread whether it's on here or another forum that gives a full run down on symptoms and all that. Good luck man

 

Hi Tyler,


The only things I could find quickly was on ebay.


ebay T-350



And I am just going by the description on my work order and memory from over a year ago.


Still looking at the slip yoke eliminator, looking at these here


4wd Jeep Drivetrain



I had not heard about these, so thank you much!

 

Thanks again for all the help my husband is looking at other sites as we speak

 

Yeah it's all about the rear pinion angle and stuff that gets messed up when you lift your vehicle? What year is your xj?

 

No problem, I remember someone saying the rear driveshaft on the newer xj'is are shorter than the old ones causing a more acute angle with a small lift such as 2 inches + which sucks because I didn't know that. I have a 98 limited and I think mine had the up country kit which had a 1 inch higher suspension lift I guess so that plus my 2 inch lift really made the thumping apparent. I'm not sure how the extended yoke would work because the rear pinion angle would be same I would think even if you had an extension. Don't quote me on that but that would be my logic

 

It is a 1994

 

Manual tranny?