Lift, Tcase, Vibes - Great Lakes XJ

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Date: Oct 28, 2008

Lift, Tcase, Vibes	Permalink

I think I save the undesireable type of transfer case where there isn't the 'cone' at the back, I'm tired and it's late so I forget what it's called. There are a lot of junkyard XJs :( that are older and do have the 'cone' that provides more support for the driveshaft (I think) but the occurance of driveline vibes is less frequent after adding a 3" lift kit. As satisfied as I am with 2" of lift, the stock tires look a little odd, but not too bad. But... after a year and a half the original leafs+aal appear to be sagging, and I'd like to just get a new set of 3" leafs for it, and I'll probably run with new coils up front if ZJ coils don't give a bad ride. So... if it's not too hard to swap the 'tail' of the tcase with the better and older style, it gives me an excuse to go up to 3" of lift over stock, and my tires aren't worn out yet (but are getting there) so then I can skip the 30s and upgrade straight to 31s while I'm at it. :) Time to start saving... I think I'd make more if I quit and mooched off the welfare system (which isn't right for someone able to work). -Matt __________________ My Fleet 1996 XJ "Snowball"- 3.5" lift, bunch of little mods. I hate pegleg rear axles! 1974 AMC Javelin "Jade Grenade"- 360v8, 4sp, green inside and out. Underfunded Project. 2009 Kawsaki Vulan 900 "Rocket III"- Summer DD

aci4369

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I'm confused, do you have vibes, or are you just planning on getting vibes if you lift higher? __________________ '99 XJ, 5.5" lift, 33" MT's '11 Dodge Charger I miss the days that they made toys that could kill a kid. Support our Troops My Pics and Specs My Build Thread

89eliminator

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yeah, are you asking any questions or just telling everyone your plan??? __________________

bmyohn

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i was gonna ask that last night, but i thought i was missing something...lol __________________

threeEs99

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AAAAaaahh, I still dont get it. I think most get rid of the tail shaft housing. Via SYE kit.
Do you currently have a np231? I think that was used in 96ish. If not you have a np242, and it would use a "Hack -n- tap" so you could use a cv type shaft. I may be wrong. I have'nt heard of a tail housing swap.
Other options are shims between leafs and axle housing or transfer case drop kit.
All will reduce or eleminate drive line vibes from a lift.

As far as skipping 30s. You could also skip the 31s to 32s with some trimming and bumpstops.

Adam help this poor lad....

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99 sport.
rust bucket, DD, 3 car seats
04 wj (w/3 car seats too)
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LEAD_NOT_FOLLOW

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threeEs99 wrote:
Adam help this poor lad....

Actually in 1996 they did change the tail cones on the NP231 TC. Pre 1996 used a cable to drive the speedo, than in 1996/97 year they went away from the cable driven speedo to an electric speedo.

Pre 1996 NP231;

Post 1996 NP231;

The 4 colored hoses you see coming out of the cone on the pre 1996 are 1984-90 specific as it controls the vac. disco on the D30 axle. After 1990 they did away with that.

With all this being said, simply swapping out the tail cones will make no effect on "vibes". If you are refering to a SYE, than this is something totaly different. A true SYE is currently only available for the NP231. This will replace the output shaft, as well as the cone and convert it from a slip yoke style to a fixed yoke (no slip) style. If you have the NP242 than your only option is the "hack and tap" SYE, which is just cutting the output shaft down, and installing a fixed yoke to the existing shaft.

I will be the first to say that a SYE is truely the ONLY solution to fixing driveline vibes. Their are other solutions out there, but they are simply just covering up the true fix. SYE's are not the cheapest solution, as they than require a new D-Shaft as well in the rear. If your not running a lot of lift, you can get away with running a front XJ AW4 equipped D-Shaft in the rear with the SYE (what we're currently doing on Rebecca's XJ). It helps keep the cost down a bit.

Getting back to "vibes".... It's hard to say if you'll get vibes or not. Some XJ's see them, others do not. It will vary greatly on what year the XJ is, the TC it has, the lift height, and several other factors. I'm at 5" of lift on my XJ with just a TC drop and have no vibes at all. I've been in other XJ's at 2" of lift and seen crazy vibes and the only solution was a SYE. Most of the time you can get away with a TC drop if your only going upto 4.5" of lift. Others have used shims to correct the pinion angle of the rear axle to help get rid of the vibes.

Another new option on the market is Motion Offroad's new "shimless" rear leaf springs. The leaf is essentially "twisted" in the center to help prevent axle wrap and no need for shims. It has the correct pinon angle already built into the leaf springs themselves. Andy (aci369) I know is running a set in his old black XJ.

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aci4369

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The new leafs were put on MysticfireXJ's XJ. It has a manual Peugot Tranny with a 231 TC I beleive. It had a 3" lift on it with very slight DL vibes. Now it has a 4.5 lift, with the new leafs prolly being over 5.5". It has a TC drop bracket and the new shimless leafs and has NO DL vibes.

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'99 XJ, 5.5" lift, 33" MT's
'11 Dodge Charger

I miss the days that they made toys that could kill a kid.

*Support our Troops*

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Chris99XJ

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I have the NP242, 4.5 inch lift, I just have shim's between my leaf's and axel. No Vibe's, Lift has been on for 2 year's.... __________________ 1999 XJ SPORT, 4.5'' LIFT, 32'' X 11.50'' TIRE'S " IF IT AINT RUFF IT AINT ME ! "

threeEs99

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4.5 Lift with a TC drop. Very little vibes. __________________ 99 sport. rust bucket, DD, 3 car seats 04 wj (w/3 car seats too) DD duty for the lady

ChevelleSSLS6

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np231, new style with short tail cone... I was told that the older XJs with the long cone 231s are less prone to vibes than the newer ones like mine with the short cone. I had vibes for a while with my 2" lift but they went away after it settled.

If I go to 3" I wouldn't want vibes, and supposedly tcase drops put stress on the engine mounts since it tilts the driveline. So, I'd likely go hack-n-tap, then again this is a strict budget project of sorts, so I don't see the 3" happening for a while.

If I could get away with the 3" lift with shims or something little rather than a hackntap or tcase drop (which is counterproductive to drop the tcase and lift the jeep), I'd do it. Otherwise I'll stick with my 2" lift, getting new leaf packs.
These are plans, but I'd like to make the best informed decision as possible.

edit: those MOR twisted leafs sound interesting biggrin

... I don't have much to complain about my rusty's 2" aal with 206k springs, but it's sagging and I'm looking to upgrade to 3 or to leave it at 2 inches.

-- Edited by ChevelleSSLS6 at 01:07, 2008-11-03

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My Fleet
1996 XJ "Snowball"- 3.5" lift, bunch of little mods. I hate pegleg rear axles!
1974 AMC Javelin "Jade Grenade"- 360v8, 4sp, green inside and out. Underfunded Project.
2009 Kawsaki Vulan 900 "Rocket III"- Summer DD

Topic: Lift, Tcase, Vibes