Hey all, getting a ton of driveline vibrations at 50+ mph after I lifted higher. From 0-50, my rig rides like a caddy, 50 plus and it's horrible. Here's my specs.

Rustys 3 inchspring pack lift, full leafs
Rustys 1inch transfer case drop
Rustys adj trackbar 5-8in lift
Teraflex 1.75in shackles
No name 2inch coil spacers
Fixed extended LCA's (correct length!!)
31x10.50 mud terrains
Jks quicker discos
Buying a drop pitman arm Friday

Just got a full balance and alignment yesterday after a huge mud jam event here in Florida. front end is basically all brand new...timken hubs, napa hd ujoints, tons of new bushings etc so it's not the steering.

My shackle angle is way off, sitting at like 90 degrees. If I can get that fixed would the vibes lessen? Trying not to pay hella $$$ for a sye. Oh and I have the 231, with the 8.25 rear. Any suggestions? Not trying to be cheap, but not trying to blow a ton of cash! Thanks all!!

That's what the lift looks like (for now!)

 

I'm pretty sure your only option here would be to get a sye.. I don't know what else you could do. Without it being a total hack job that is...

Shim the rear maybe?

 

Would fixing my shackle angle help? Not tryin to hack Job my rig. It's a dd, and every now and then my toddler is in it. Gotta be safe!

 

And this whole sye, shim, hack n tap etc....it's all Chinese to me. When i was younger with other xjs I never went bigger then 3 inches. Now I'm old and at 5+ inches. Lol I blame my neighbor who has a HUUUuUge Xj. Peer pressure

 

^ This. If you drop the TC you need to shim the pinion up a little. The lift shackle should provide a little relief in your pinion angle, but the pinion and TC output shaft should be parallel.

Also, have you replaced your U-joints on the read DS? Greased your slip yoke?

If none of that works then you are probably going to have to go with the SYE.

 

Worth a shot to try all that. I'll get it knocked out this weekend, hopefully it works

 

I agree. Replace your u joints. They are like 10 bucks each and could definitely help the vibes.

The shims will help get the angle better too. But sometimes esp on 97+ XJ's they need a sye. They aren't as expensive as you may think also. This is why I've always stayed at 3 in the past bc I didn't want to open a can of worms. My 00 at 3inches of lift and a rustys tcase drop still has slight vibes. I'm doing a sye because I plan on going an inch higher soon to compensate for added weight and whatnot. It's a good investment.

 

I'll need a new driveshaft with an sye yes? Any recommendations?

 

Yes you will need a "custom" lift driveshaft with a sye. Or a front driveshaft from an xj will work.

 

Soooo I can run a front DS from a junkyard instead of custom?

 

*probably*

Every XJ is different and I've heard of them not working for some, that they're too short.

If you're going the cheapest route possible, get the hack n' tap yoke from ironrockoffroad.com and a junkyard front driveshaft and you should be good to go.

 

I'll take a look at the iro sye. Just gotta ditch the vibrations!

 

Rustys has an extended yoke.... Hmm,?

 

what year is your xj?
Im sure the Iron rock kit would work fine with a front driveshaft

 

It's a 2000.

Ended up buyin some 6* shims. Having a local spring shop make me the center pins. Wish me luck!