Just installed a 3" Zone Offroad lift kit with new leaf packs, shocks, and 31" mud tires. With little surprise, the driveshaft is now super slanted and makes vibration at around 50mph, with grinding noises when throttling up/down.

As i haven't done a ton of research on this, what is the BEST fix for this?? I've read that a SYE is the fix, but can anybody confirm that?? I was contemplating a SYE that retrofits the transfer case for a fixed output. Outside of installing a 3/4" transfer case cross drop kit, is there any other fix?

I'm hesitant to put in these X-member spacers b/c the studs for the X-member are super ceased into the chassis and i've already broken a bolt in the chassis and had an awful time getting it out. Better yet, how effective are these X-member drop spacers??? Even if i dropped the X-member 3/4", am i still going to be wearing the back of my transfer case out prematurely??

Dropping the transfer case seems like a crappy short term fix for a long term problem b/c we'd be lowering the case 3/4", at the cost of tilting the engine/trans/everything connected to it. Plus, lowering the case is exactly the opposite of why we lifted the car in the first place! Is factory armor able to be fitted to the transfer case with the drop kit installed???

Thanks!

 

Yes an SYE is what you need. If you have a 231 tc you have choices. If you have a 242 then a hack n tap is your only choice.

Edit: Also stop calling a XJ a car. That is all.

 

I had the same problem with my jeep I bought it with 4.5" long arm lift kit that all ready had the sye kit installed sitting on 33'', but I still had a pretty bad vibration. I bought a TK drop kit for it, the vibration wasn't as bad. but unfortunately after a long drip this weekend about 400 miles my bellhousing busted all the way up the right hand side


I'm pretty sure that this was due to the tk drop kit that was installed. so after I get this fixed I'm wondering if adjusting my axle angel will help or installing 1'' motor mounts and the tk drop kit will fix this problem.

 

Don't install motor lift mounts. Solve the vibration. Remove the transfer case drop. Installing a Slip yoke eliminator with a new longer CV-style driveshaft is the best / strongest / long term solution. You will also have to shim your rear axle if you get a CV shaft so that you are pointing your diff "up" a bit towards your transfer case.

Is your rear axle shimmed? Get a cheap angle finder and measure your rear & front driveshaft angles, as well as the angle your differentials are sitting at. Remove the driveshaft, and measure against the pinion yoke and write all the numbers down. Sometimes you can try to just shim it and phase out the single cardan shaft that is stock. It doesn't always work though.

http://www.4xshaft.com/vibrations.asp
http://www.4xshaft.com/tech_slopesVSangles.asp
http://www.4xshaft.com/driveline101.asp

I'd recommend reading these few links as they will explain most everything you need.

Replacing motor & trans mount never hurts to keep the jeep nice & quiet and strong though. I still need to do the mounts on mine.

 

Even with the SYE, you will still need shims to orient the rear diff properly. This should get rid of the vibrations....

 

Well I all ready have the sye kit installed with the CV axle drive shaft. I'm getting a D44 from a TJ in a few months so I will need to cut the old mounts and weld new perches for the springs on so I plan on welding them at the correct angle to get rid of the vibration.

 

So me and my buddy spent the last few hours tearing apart my jeep. here is a few pictures of what happen.


My rear dive shaft is destroyed, my oil tube in the transfer case is gone, all the bolt holding the transfer case to the tranny where finger tight.


I would think this would have to do with the drive line angle and not torqueing the nuts and bolts to spec.


but have rebuilt kits coming for tranny an transfer, and new bell housing

 

That right there, I give you an A+ on destruction. How exactly did this happen ?

 

That I couldn't tell you, I'm assuming it was from the transfer cases drop kit that was installed and the fact that the person that installed the SYE kit didn't torque any of the bolts, almost every bolt taken off the transfer case and transmission where loosened by finger and for some reason there was no fluid in the transmission or transfer case.


I've driven a few thousand miles on it all ready and been wheeling and mobbing pretty hard and every thing held to gather.

 

If it was a shop you paid to do this work for you I would think it was "Not" a 4x4 repair shop. No matter I would take it back to them and have pay for everything if in fact it was their fault.

But you did say you had it out 4 wheeling and that could imply you may have damaged it yourself. The loose bolts can be caused by vibration, but I think not all of them. Don't you go over your jeep as soon as you get back from off roading to see if you have any problems to take care of before they get to be big one's?

 

I didn't take it to any one i bought it with the lift on it. and it didn't happen while i was out wheeling i took a 400 mile trip on highway. I wouldn't have paid for any one to install a lift on my jeep. the only think i would bring it to a shop for is to have the driveline angles set by a actually driveline shop

I'm just taking a guess and thinking it was the transfer case drop kit that add the extra stress to the bell housing to cause this to happen

 

OK, that basically confirms that a transfer case drop kit is basically a bandaid type fix.
The new question is, what's the best quality SYE kit to buy and what driveshaft do i need??
I was thinking about buying this kit:
http://www.rockridge4wd.com/Jeep-XJ-...cv-sye-kit.htm

It's kinda $$$ though and i think there's $$ to be saved by buying the SYE separate from the driveshaft.

 

Yes take it from me don't mess with the TC drop kit... it just adds stress to parts that aren't designed for the changed angles, locations etc. Go straight for the SYE kit and do the axle shims if needed. I just installed an SYE and had a new drive shaft made. I went with the Advanced Adapters SYE, and did it all myself... (AA SYE looks very similar to the one you linked above) If you are planning on doing the SYE yourself there are plenty of write ups/videos on the install. Just make sure you get/have both "snap ring" pliers and "lock ring" pliers. As far as $$$ you are going to get the best deal buying the SYE/Drive Shaft combo... I was given my SYE Kit for Christmas but still had to pay a local Driveline $300 for my new driveshaft..

 

I think any seized bolts and studs on the x-member are going to be a problem for installing the sye also if the prevent removing the x-member.

 

I installed my SYE while the transfer case was still installed in the Jeep.. So no removal of the X-memeber needed. Granted I had the TC drop on prior which means it was easier to access the top most bolts on TC halves.... But I think it still can been done in stock form... Hopefully someone else will chime and confirm.