SteveMongr

Tough one to diagnose. Here is a cut away picture of the 242 transfer case that shows internals.

krazo

***UPDATE***

well it wasnt my transfer case. the shop replaced it and the vibrations/grinding still there. SO they ended up putting a t-case drop on and PROBLEM SOLVED!! im surprised this is all it took. i didnt think this would be necessary with the suspension upgrades I did but glad to get rid of the vibration. drives much smoother now.

PatHenry

Do you have any lift or is it at stock height? I skimmed the first page and didn't see any mention.

krazo

its a factory 01 and had the original leafs, coils and shocks. i pull a camper and with 235x75 i was rubbing with the load. SO, i put on crown leafs, standard dorman shackles, gabriel air shocks in rear, moog cc782 coils w/ .75 spacer to level and standard gabriel front shocks. Upcountry lift, should be stock upcountry height but hasnt dropped much in 400+ miles so far. im at 20" from center of wheel to bottom of fender flare. it sits higher than I thought it would so far. maybe it'll settle in more. but i'm not a wheeler, this is my DD, hunting, camping, fishing rig. so the t-case drop shouldnt really cause me any grief with my loss of clearance.

PatHenry

Ah.. I'm asking because I recently did my leafs and it's the same - they're slightly higher than spec and haven't settled down. I'm at stock height as well and I get a little bit of a vibration at 55+. I had attributed it to damage to my driveshaft due to poor work at my previously trusted shop.
I'll have to load up the trunk (I need some cement in the near future anyway) and drive it on the highway and see if that affects the vibe.
I dread having to deal with removing the crossmember since I broke the studs and dropped bolts in from above, but your experience gives me at least a lead on a possible correction.

Thanks!

krazo

from what i understand a CV axel and SYE are another fix but a lot more $$ however you dont lose the ground clearance. may be other benefits too idk.

ktb615

This is very interesting, as I have heard time and time again that a TC drop is not needed for the upcountry suspension. Now with your success, I want to give it a try before moving on to the more expensive options. Do you have any information on which TC drop kit they used, or at least specs?

jordan96xj

I did the upcountry style lift on my 96 (and also have rear gabriel air shocks) and did not have to lower the transfer case for vibrations. Though I have heard that the 96 and older XJs were more tolerant in this regard.

But the previous post mentioned 20" between center cap and flair, and that is a lot for an "up country" clone. So he might have just been over the line of what the u-joints could handle in terms of angles. Mine was somewhere like 18.75" at first and settled to 18.5" (don't quote me, but definitely not as high as 20").

The SYE achieves the same outcome as a transfer case drop. Which is to reduce the angles encountered by the u-joints. It just does it without sacrificing clearance, unlike a transfer case drop which slightly penalizes the vehicle's "break over angle" or the angle at which the vehicle can go over an obstacle like the top of a hill without hitting the frame or underside components. So those that have put a lot of time and money into their lift for maximum capability, they don't want to undo all of that effort by having the cross member hanging 1" lower. So off-road purists look at the transfer case drop as being a little "poser-ish" or "mall-crawler". But for many folks, its a decent option, and much simpler/cheaper.

By CV axle, I think they meant a CV style drive shaft, which is usually installed when doing an SYE. It is similar to your front drive shaft, which is shorter and must deal with harsher u-joint angles. So it spreads those larger angles over 3 joints instead of 2 using the cardan joint. Take a look at your front drive shaft for reference. The rear axle of course has no joints of its own.

PatHenry

Excellent explanation Jordan (as always).

You don't need a fancy kit to drop the xfer case - a few grade 8 washers and possibly longer bolts is usually enough. I don't remember how much extra length was on the studs, but I can see that as the biggest hurdle of doing the drop on an XJ.

When mine snapped I contemplated drilling off to the side of the stud, I'm not sure if that's a great idea, but it seemed possible.

In my case I'm not convinced my vibe is not due to an imbalance of the driveshaft. I'm going to be looking into either finding an undamaged shaft or balancing mine, but since I need cement anyway, I'll at least test whether lowering the t-case to axle distance makes a difference.

krazo

no idea what kit they used. but its basically some 1" rubber spacers on the bolts. looks like an easy install. def got rid of the vibration. total cost for me was 127.xx, 90for labor, 30for the kit, and taxes. kit seems expensive though. I think i saw some for like 8.99. and I prob could have put it on and im no real mechanic.

firebane

Stock height is around 17" which would put you at 3" of lift which is borderline sye territory.

This is why your getting vibrations for.

krazo

ktb615

ktb615

Just wanted to come back to this thread in case someone else ends up with the same problem and add that I finally got my transfer case drop installed and all my vibrations and noises went away. In the future I'll probably go the SYE route.