At my wits' end! (kinda long)

Here is the situation:
1 week ago, put on RE 4.5 coils and S-10 / Cherokee bastard leaf pack. It all lifted the XJ just under 5".
At the time I put the leaves on, I shimmed the axle 3*. I shimmed it so that the pinion pointed up more toward the TC. ( I know this is wrong now, but back in the "day" w/ Blazers and Pickups, we always seemed to do that).
I had just a hint of vibration under acceleration only at speeds of 30-40.
I read about the shims being wrong on this forum. So I dropped the axled again and reversed them the "Right" way.
I had WORSE vibration. So I installed a new factory transmission mount today to stiffen things up a little under there.... MAN its bad now! Under all acceleration, it vibrates to beat the band.

So... Do I:
1) Put the shims back the way they were to begin with?
2) Remove the shims alltogether?
3) Drop the TC? (I really dont like this idea for a number of reasons)
4) Get a double cardon shaft and just point the pinion straight at the TC?
5) Get a SYE and point the pinion straight at the TC?

I have searched, and yes, there is weeks worth of reading. But I honestly can say that I dont really understand the dynamics of the whole "driveline" thing. I need someone who can explain it simply, or who has fought this same battle and can tell me what needs done. It is to the point that I want to drop it all back down now. (sigh)

Thanks for any help.

James

Measure the angles,then shim as needed,quite simple!If that doesnt work then drop mount or sye.What year?

DSN46 said:

I need someone who can explain it simply, or who has fought this same battle and can tell me what needs done. It is to the point that I want to drop it all back down now. (sigh)

Thanks for any help.

James

Click to expand...

http://www.pirate4x4.com/tech/billavista/PR-shaft/index2.html

Great Write-Up!
Thank you for the link. I hope that I can figure it all out.
I'll let you know what I have to end up doing.

James

For RCPPhx,
Sorry I forgot to mention. It is a '96, 4.0 ltr. with an AW4 and NP242.

James

Switch your 3* shims back for now or get larger shims for now. then get a fixed yoke kit or sye. and you'll be vibe free in no time. spend the money on a tom woods sye.

bholt5035 said:

Switch your 3* shims back for now or get larger shims for now. then get a fixed yoke kit or sye. and you'll be vibe free in no time. spend the money on a tom woods sye.

Click to expand...

yeah cause he is the only one on the market......there are tons of options for sye. PORC makes a very reasonably priced one. The vibe thing is not an exact science you have to play around to get things right. every rig is different.

jrsxj98 said:

yeah cause he is the only one on the market......there are tons of options for sye. PORC makes a very reasonably priced one. The vibe thing is not an exact science you have to play around to get things right. every rig is different.

Click to expand...

Not for a NP242.

Bholt5035,

I switched the shims back today so that they move the pinion up toward the TC like you suggested. That, along with the new Tranny mount I installed has taken away about 85% of the vibes! Thanks.

Now I am going to try to drop the TC 1" to see if I can get rid of all of it. Not sure exactly how I'm going to back the studs out of the unibody though!
I've tried the old "jam-nuts together" routine before, and it has never worked for me. I don't want to bugger up the threads using vice grips and then fail at getting them out either.. then there the Jeep sits...and it is my DD.

Thanks again.

James

1) T-case drop sucks for off-road, it gets hung up on everything!
2) weld nut to stud, remove with socket

It's done.
1" TC drop did the trick. Thanks for all the input on this one guys.

By the way, it does feel better when you do all the labor on a lift yourself, I now know my own suspension, shocks, driveline etc. better than anyone else since I spent the time crawling and scratching around underneath it.
Have lifted Jeeps and Trucks in my driveway in the the past, but thought about paying someone else to do this one... glad I didn't now.

Take care.

James