Warbird56

Hi, I have a 99 XJ that I did a 2 inch spacer (front) and block (rear) lift to. I had bad vibes between 30-40 mph which was fixed with a doulbe cardan drive shaft however now I have less extreme but very noticeablr vibes over 52 mph that get worse as the speed increases. It has new tires and I rebuilt the front shaft. It did not have this problem prior to the lift. I am thinking it needs a tc drop kit. Any advice would help. If so what size drop would you recommend? I am going to put the rear up on jack stands tomorrow and see if I can tell whats happening.

Thanks

Rmart30

Ive had a 97 and a 99 that had small BB lifts done to them and both ended up needing a T/c drop even with that small of lift.

DaveD

http://www.cherokeeforum.com/f11/t-c...kit-1-a-89972/

red97cherokeewithsunroof

tc drop...1" should be fine, AND re locate your track bar. get an alignment if those dont work. also check u-joints in the axels. had to replace mine and it all these things above made it go away COMPLETELY

Warbird56

Will do, thanks to all for the advice!

Brown Dog

If 1" doesn't quiet the vibes, washers can be used to fine-tune the T-case drop. Unfortunately not every vehicle is the same after the age and miles .... kind of like me.

93gc40

How did you mount the DC drive shaft???? Did you adjust the pinion angle yet? Rear pinion should be pointed AT the TC output shaft. You DON'T use a TC drop with a double cardin drive shaft. Check the U-joints?

Warbird56

I did mount the DC shaft pointing directly at the transfer case less about 2 degrees. The initial bad vibes between 30-40 mph were right after the lift was installed with the original shaft, even with shimming. The dc shaft eliminated the bad vibes between 30-40 pmh but I now have some vibes, not as bad, over 53 mph. I installed 4 new tires and did an alignment. Now I am going to put the rear axle up on stands and have someone run the dirve line up to those speeds and see if I can see where it is coming from. I waas servicing my sons 98 2dr XJ today and noticed the rear shaft has very mimimal anlges at both ends, I think this is what I need and the TC drop hopefully should help with this. Also I have seen threads talking about the 4x4 shifter having problems after a tc drop, does anybody have any experience/advice on that?

BTW, I just did a heater core and AC evap in case anybody needs advice on that job.

1armyguy

I have done a 1" homebrew tc drop and it didn't affect my shift linkage for the transfer.

Kuro89

check the u-joints, my buddy drove around with vibe then we did the t-case drop and he started getting vibes again and sure enough the u-joints were trash

Warbird56

Well I found that the transfer case was where all the vibrations were coming from meaning the double cardan shaft was not enough in this case to quiet the vibes. I am lucky in that the gut I bought the shaft from will take it back and sell me the SYE kit for the difference between the two kits. I am currently in the process of doing the short shaft install. Will post back on when all is done.

ericfx1984

Huh? you installed a double cardan rear shaft with out a SYE? I am confused

PJsJeep

Ya there are some on ebay for sale. Like this http://cgi.ebay.com/ebaymotors/JEEP-...Q5fAccessories

which is more expensive than hack and tap.

Are you sure your tires are balanced. tires not balanced will cause a vibration on highway speeds.

Warbird56

Yes, you can sometimes get away with just the DC shaft and a TC lowering kit, in my case that shaft it took away the bad vibes at low speeds but there was still vibes at 53 mph+. Since the shop I bought it from was willing to take the DC shaft back and apply it towards the SYE I decided to so that instead of lowering the TC. The new shaft is on it's way, I'll post back when I try it out.

Summers here, make the best of every minute!

Warbird56

I ran the jeep on 4 jack stands and could feel the vibes at the TC case, the tires are brand new.