Vibration Q's NP242 owners speak up!

Searched but probably under the wrong terms. I have a 96' XJ with an NP242. I want to install a lift but I am worried about getting vibrations, I read that the NP242 sits approx. 2" lower then an NP231. Since my case apparently sits lower does it also have a flatter (better) drive shaft angle? I am looking at V8 ZJ Coils + 1" Spacer and 2.5" Lift Leafs from Procomp and want to run 31" BFG's, don't feel like trimming my XJ just yet. Would I be able to run a 3-3.5" lift safely without dropping the Tcase? I am a little worried about major rubbage so I may drop down to 30" BFG's

I can't speak for newer XJ's, but with my '89, I ran 31's with 3" of lift without any rubbing (except for the LCA at full steering lock). The driveline vibration question is even harder to answer. I've heard of folks going 4" and higher without any vibes, and also heard of folks who got vibes with only 2" of lift. I'm not sure the 242 sits any lower (mine is a 242), but I had vibes with 3" of lift. A TC lowering kit took care of about 90% of the vibes...SYE is in the works for me. I say do it and find out. If you need a TC lowering kit...they're cheap and easy to install.

I want to stay away from dropping the Tcase... no sence in raising it 3" to lose 1"

the case does not 'sit' lower. it hangs lower because it is bigger.

J-Roc said:

I want to stay away from dropping the Tcase... no sence in raising it 3" to lose 1"

Click to expand...

Then you ought to be ready to spend some $$$ for a custom driveshaft if you don't like replacing U-joints every 5k-7k mi. I have a 1990 3" lift w/ 242 and I had to drop the crossmember with 1"x1" 1/8" cold rolled to help out the U-joints.

I guess I am just going to have to see what happens, everybody seems to get a different answer. With the luck I have been getting lately, I probably will get vibs...

I guess it depends on your reason for the lift. I lifted mine primarily to enable me to fit larger tires, and to increase articulation. In all the rock-crawling and wheeling I've done since my lift and t-case lowering, I've never banged the t-case. I consider the t-case lowering a temporary fix until I can do the SYE & new driveshaft mod.

IntrepidXJ said:

the case does not 'sit' lower. it hangs lower because it is bigger.

Click to expand...

I did tons of research before I put on my lift and I went with the Tom Woods setup. I did not drop the T-Case and I have zero vibes from the back and the piece of mind that I'll get another 100K out of my XJ. I saved for years to do it right because I didn't want to try and cut corners just to replace parts in the future. I live in Colorado and I like the 4 full-time feature of the NP242 for snow.

There are many people on here that run a hack n tap with the 242 with success but there are some that have later converted to a Tom Woods setup.

After putting on the lift (and before the Tom Woods kit) I had unreal vibes. I can't believe it would have been something you could have fixed with a 1" TCase drop and some shims.

Good luck.

Flyfisher said:

I guess it depends on your reason for the lift. I lifted mine primarily to enable me to fit larger tires, and to increase articulation. In all the rock-crawling and wheeling I've done since my lift and t-case lowering, I've never banged the t-case. I consider the t-case lowering a temporary fix until I can do the SYE & new driveshaft mod.

Click to expand...

I am with you on banging the transfer case (it has never taken anything other than a rub) and I have wheeled it over rock in creek beds and trails.

I have, however, banged the front diff and rear diff. I have a TC skid plate also.
It depend a big part on the "line" you take.

sounds like the best thing to do is get a tom woods SYE kit... I'll look into it and ask more Q's if I am confused.

About eight years ago I installed an RE 4.5" lift & immediately installed a Currie 242 t/c to 231 tailshaft sye and cv driveshaft Tom Woods built when he was there.

The combo is golden, slight shimming needed but I hear that's normal. All I hear now is the hum of the BFG AT's.

I don't hear much about the Currie sye anymore, must admit I rarely go hardcore wheeling, but there are no vibes at all, at least with this combo on a '98 w/8.25.

J-Roc said:

I want to stay away from dropping the Tcase... no sence in raising it 3" to lose 1"

Click to expand...

It is about $$$ isn't it. I know it a personal thing and it don't look kosher but I already raised my XJ and can't put in $500 for a SYE and DS so I went the $25 route. But I'm still wheeling it. I got bills like a mortgage for a house in California and just spent $60,000 for the kid to go through college and did I mention I paid cash for the Jeep new and a new Toyota and a Mazda Tribute (well the wife helped). I think I'll put rock sliders on next.