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burntkat
December 4th, 2017, 06:34
I have a 1997 XJ, 4X4, 4.0, AW4, etc. I just "forklifted" the suspension- meaning I replaced every component of it- 4" rear springs, shocks, Upcountry front coils, added ACOS, Iron Rock Offroad trackbar, 31" tires, etc.

The vehicle is fine to drive up to 45MPH. After that, I either have a bad shimmy, or mild death wobble- not sure of the defining line between the two. I know that at around 45 it'll start shaking a little, and it feels as though if I don't brake smoothly it will continue to get worse. This is my son's vehicle and he regularly commutes a mile in a 50mph zone to get to school and work. I want to solve this problem ASAP.

I've examined the front end while my son steers- the trackbar seems to be hoding the axle in place just fine (I've got 150ftlbs at the axle bolt- upgraded to the Clayton H/D bolt kit and 80 at the frame bracket. Frame bracket bolts are tight, and the bracket doesn't appear to be moving. I've replaced the pitman arm TRE as I saw a little movement there. I'm not sure I trust the other TREs although I'm not seeing any movement in them. I have them on order at Oreilly's, going to replace as soon as I get time to realign the vehicle.

I tested the balljoints by using a long lever with a piece of 4X6 in front of the raised tire and looking/listening for movement or clunking. Nothing appears evident.

All control arm bushings appear intact, with the bolt centered in the bushing body.

Wheel bearings were tested as well, by lifting the wheel and trying to shake side to side. I see a *little* bit of movement in one wheel but I'm not sure it's out of spec. It may be the TREs. As I said, not sure I trust them- at the very least, they all have ruptured boots and so I'm replacing them out of due diligence. I don't get any shake out of them, and when I rotate the bars they stay in place.

I noticed this vehicle doesn't have a disconnect in the front axle. Thus, front propshaft rotates as the tires do. Might that have an impact on DW? At any rate, the joints all appear fine.

Kind of at a loss where to go here. I had a similar issue with the wife's ZJ last year, of course it's basically the same suspension. I solved that problem by forklifting everythng in the front axle- hub bearings, control arms (full set F/R of Core4X4 arms with poly bushings), ball joints, TREs, axle shaft u-joints, wheels and tires. I just can't afford the Parts Shotgun approach on this vehicle at the moment, as I've already put $2000 into the suspension for a vehicle I paid $1000 for. Admittedly I got a steal of a deal, but still.

Anyone have any insight? Is it possible for balljoints to be bad even after passing the shake/lever test? How about control arm bushings- is there a more definitive test for them than "that looks right"?

Bent
December 4th, 2017, 06:46
Castor too far forward/positive?

BenWheelin
December 4th, 2017, 06:49
You didn't mention the steering stabilizer, cheap enough to start. New or used tires?

Maybe try it on your old tires, I had it start suddenly one day but didn't notice the knot in a tire for months. Looked and looked, went over everything, and it was a tire.

burntkat
December 4th, 2017, 07:17
Castor too far forward/positive?

Good catch. I meaasured it at 6deg pos (top toward back). This is about spot-on IIRC.

burntkat
December 4th, 2017, 07:17
You didn't mention the steering stabilizer, cheap enough to start. New or used tires?

Maybe try it on your old tires, I had it start suddenly one day but didn't notice the knot in a tire for months. Looked and looked, went over everything, and it was a tire.

Steering stab was replaced after purchase of the vehicle, 4 months ago. Besides, they mask DW, don't cause it.

Tires are new.

burntkat
December 4th, 2017, 07:39
More information:
I aligned the vehicle by tape measure. This isn't the first time I've done it, and my SAS'd S10 and the wife's 4" lifted ZJ both are able to roll out at 70MPH without issue. (granted the SAS'd S10 has a leaf front suspension, but the point is my alignment and balance is good).

BTW- wheel balance- wheels are balanced with a combination of a static balance job (weights taped to the inside of the rim to do the heavy lifting part of the balance job), and use of Centramatic balancers (to put a fine polish on the balance, actively as the wheel rolls down the highway). I've never had a problem with this method, even using just the centramtics up to a 33" tire.

RCP Phx
December 4th, 2017, 09:18
4" is a lot when using the factory control arm mounts and that carries thru to drag link angles!

burntkat
December 4th, 2017, 09:36
4" is a lot when using the factory control arm mounts and that carries thru to drag link angles!

True, but I'm using the same setup on the wife's ZJ at 4", and my 90 XJ at 6".

Sub-optimum, certainly agree. But it isn't a guaranteed no-go.

BenWheelin
December 5th, 2017, 17:14
More information:
I aligned the vehicle by tape measure. This isn't the first time I've done it, and my SAS'd S10 and the wife's 4" lifted ZJ both are able to roll out at 70MPH without issue. (granted the SAS'd S10 has a leaf front suspension, but the point is my alignment and balance is good).

BTW- wheel balance- wheels are balanced with a combination of a static balance job (weights taped to the inside of the rim to do the heavy lifting part of the balance job), and use of Centramatic balancers (to put a fine polish on the balance, actively as the wheel rolls down the highway). I've never had a problem with this method, even using just the centramtics up to a 33" tire.

Tape measure method should be fine if it doesn't pull. Did you relieve the control arm bolts at the new ride height to let the bushings unload?

I've experienced it from a bad steering box, but it was already leaking from the pitman shaft, and from wheel bearings. I'm sure you would have noticed play there by now.

burntkat
December 6th, 2017, 06:16
I haven't relieved the stress on the bushings- hadn't even thought about that.

Steering box is brand new rebuilt unit from Oreilly. There are no leaks in it- however I think there may be a little bit of movement in the sector shaft. There's no leaks there, as I said, however- not sure how that is even possible.

I have new wheel bearings on the way, although I'm not convinced they're bad. The DSPO told me the vehicle was "well maintained"... I've come to the conclusion he's a damn liar. The shocks were the OEM units, FFS! I could tell because they were 1- rusted to crap, and 2- had Chrysler emblems on them. Even with that, it still rode well. It rides much better now, except for the 40mph limitation.

Green XJ Jeep
December 6th, 2017, 19:28
Moog lower control arms are $30 at rockauto.

Chances are the bushings in the control arms are a little worse for wear. Especially with the new angles

burntkat
December 6th, 2017, 20:37
Yep, that's the way I'm leaning as well. I'm just going to replace the bushings though. I have the tools to do the job. My only concern is rust on the fasteners

burntkat
December 11th, 2017, 04:07
Replaced all the steering rods and ends yesterday. Literally everything from side to side that bolts to the pitman to the knuckles. MUCH improvement, I've had the truck to 60 briefly now. It's smooth but I do get an occasional heavy vibration (like a heavy shimmy, or moderate DW) from 45-50, however it is intermittent. Comes and goes, without apparent reason (ie, bumps or potholes don't appear to have anything to do with it).

I think it may be a harmonic of my wheel balance occasionally coinciding with a flaw in a wheel bearing... These are 20 years old after all. I balanced my wheels on a static balancer, and will switch over some Centramatic balancers from the wife's ZJ this evening. If the problem goes away I'll leave them on for a bit till I can get him his own set. Meanwhile I have new bearings to go on the jeep, just didn't have time to install them this weekend. I'll also do ball joints in a week or two as a precaution, and I have a set of poly bushes arriving today. Yes I understand they will limit flex, this is not a trail vehicle. I'll grease the snot out of them and install, and won't have to worry about them again until we are ready to consider a more major suspension upgrade (longarms). He wants to pursue a career in automobile customization and will be beginning work on his welding certification next year.... Once he has that we will look into our own take on a Clayton longarm system like I have in the 90.

burntkat
December 17th, 2017, 14:58
I'm in the process of replacing the hub bearings. 2 of 3 bolts sheered off on the passenger side. Removed the hub and found that there is some notchiness to the bearing, and the passenger side axle is just an abortion. The joint has a lot of slop in it, and the inner shaft has the trunnion cap welded to the yoke... Either cold (JB Weld) or an actual weld, I can't tell for sure - either way it's a shit-show.
Pretty sure this is my problem. I won't know until Wednesday, soonest. I had to order new hardware for the hub bearing, obviously.
While I'm at it I went ahead and gave the boy an early Christmas gift - Ten Factory tube seals. I can't say he's got much under the tree, because most of his Christmas has been installed already.

EDIT to add- the hub bearing on that side is notchy as well. I haven't examined the driver side yet but am servicing it as well. I ordered a full set of hub hardware (2 packs at 3 per pack) as I don't like to run old with new, and it appears the new has 6-point hardware anyway.

BenWheelin
December 23rd, 2017, 06:23
I understand welding the caps is common, but I wouldn't do it myself. Sucks to hear you had so much trouble with the wheel bearings.

I just found my control arm bolts were loose after my last trip, hadn't been checked in a good hundred thousand miles but I noticed the slack after two days and a hundred or so miles of trails. No death wobble, just noise letting go of the brakes backing up.

I swapped a whole steering setup from an 01 to a 92 once and adjusted it with a tape measure. It had some wheel bearing noise but it drove fine. When I replaced the bearings, it began to pull hard and required an additional adjustment. Food for thought.

burntkat
December 23rd, 2017, 08:30
I'm using the proper parts and there is no pulling.

Replaced the broken bolts with gr10.9 6 point bolts from Lowes. M12X1.75X90, IIRC. Sloppy with the antiseize on reassembly. Brake hardware is new and also lubricated.

Still have dw but it's still intermittent in the same range. I think I mentioned that the passenger side axle has a bad joint I hadn't replaced yet. That's on the agenda for today. I'm thinking (hoping, praying) that might do the trick

burntkat
December 23rd, 2017, 18:49
Replaced the passenger side joint. It was well and truly pooched. Reassembled... And the wobble is worse.
Sonofabitch. This is really getting old.

Bent
December 23rd, 2017, 19:34
Did you end up with the formerly rear tires on the front? It's a reach, but maybe the rears were out of balance? Maybe on a bent rim?

burntkat
December 23rd, 2017, 20:38
Pretty sure I said the wheels and tires are new.
That said, I'm going to swap over the wife's ZJ wheels and tires. I had a similar problem with it last year that was solved by replacing everything.

burntkat
December 23rd, 2017, 20:39
Also, I balanced the wheels on all my vehicles myself. I know the balance is dno.

Also, running Centramatic balancers, so they are actively balanced during use. Balance is absolutely not the issue

BenWheelin
December 24th, 2017, 07:12
Rereading, when you have someone steer while you observe, is that person turning lock to lock or bouncing the wheel back and forth? I find things most obvious with the latter, and the engine off. I also had an assistant back up in reverse while I observed the front axle, as it was shifting when the brake was released. It makes any slack in the control arm bushings pretty obvious.

My pitman shaft was pretty obvious, but it was also leaking.

Those new rear leaves come with a main leaf and bushings?

I've had several of these with the non disconnect axle and prefer it over the alternative. Get shafts for an ABS model, note the extra material. Never had an issue related, it's not the axle. You might check the play in the compensating joint in the front shaft and pinion, but I feel that's unrelated and produces its own symptoms.

I've lifted a couple now to four and a half, both times with the original track bar and pitman arm. Actually, one has a ZJ pitman, but no drop bracket or adjustable track bar. Other than pulling the axle over just noticeably, they drive fine. It should be noted that at four and a half inches, the joint on the factory track bar doesn't hold up to off road use for long, and I wouldn't endorse it as a long term setup.

Perhaps you should check that stabilizer now that it's become more intermittent. It should be positive at any point in it's range of motion. If it pulls light for a quarter inch or so, it's done. There's a chance you resolved the majority of the cause, but driving it in the meantime may have killed the stabilizer. I've had those which drove fine without it, but might be set off by a certain series of bumps in the road. Might not have a problem for weeks, such that I'd forget I needed a stabilizer.

Bent
December 24th, 2017, 07:21
Pretty sure I said the wheels and tires are new.
That said, I'm going to swap over the wife's ZJ wheels and tires. I had a similar problem with it last year that was solved by replacing everything.
Figured it was a reach. I also have the attention span of a gnat.

burntkat
December 24th, 2017, 09:57
Figured it was a reach. I also have the attention span of a gnat.

Hey, absolutely no problem. I appreciate the input. I can totally relate about attention span....

burntkat
December 24th, 2017, 17:03
Bought the KOR death wobble pdf hoping to gain some extra knowledge on the issue. Glad I didn't pay full price. While I did learn something new, it would have been money better spent elsewhere. Oh well.

Will have my son shift into 4lo and torque the drivetrain as I observe, tomorrow. Maybe that will show me something.

I'm considering putting a KOR HD bushing in the IRO trackbar, but I really don't think I buy the marketing BS that it would be a solution, anymore than I believe that rubber bushings are so superior to poly.

BenWheelin
December 24th, 2017, 17:32
For what it's worth, I had mine in full time when I observed my bushing slack, but part time should be just the same. I have a good bit of slack in my 300k mile original bushings and it drives pretty well without a stabilizer.

Pay close attention to the bolt heads and nuts during your observation, body side and frame.

burntkat
January 2nd, 2018, 06:31
Had the boy shift into 4Lo and load up the suspension. No movement observed in the bushings or control arms. Even though I have a bushing kit, I'm going to leave that for last.

I did see about 1/4" of movement in the steering dampener. Removed it(8 month old Rough Country part) and inspected. No dead spots, but the bushing in the axle end appeared to be for a 1/2" bolt, leaving slack as it's 12MM or so. Replaced the hardware with GR8 1/2-13X2.5" hardware, and went ahead and put a new Moog dampener on as well. Granted, it's the cheapest dampewner Moog makes for this application.

I am considering biting the bullet and getting the OME $90 unit. Yes it is by some considerations "not a fix"- but if it makes the DW go away, then it's a fix...

I'm going to go ahead and buy new Moog balljoints as they are one of two things I've yet to address- balljoints and control arm bushings. Once those are done, EVERYTHING up front that rotates/slides/rolls will be new, from the steering box to the shat ujoints.

Still haven't done the driver side shaft joint (everyone in town that stocks a "Greasable" ujoint for the application, presently is only able to supply nongreasable- ie, their joints are defective- supposd to be greasable and aren't. I won't run a non-greasable joint), but it is nice and tight and honestly perfect.

I did feel a tad of slop in the brand new TREs. I am running the same joints on the wife's ZJ and they are fine, however. I won't replace them yet as they can't be the problem- I can feel but not measure/see any movement. Going forward, however, I will use Moog TREs only. I just won't buy them at the LAPS, no sense paying 4X the price.

I also saw a tiny bit of movement at the brand new IRO track bar system's frame bracket joint. IE: the bushing there moves just a tiny bit. I feel it shouldn't move at all, especially for the price. It's a good kit, but it escapes me why they kept the 7/16" bolt at the bracket end. I will be removing their bushing and going with a poly bush that will allow a 9/16" bolt, and will drill out their frame bracket to suit. Basically the same thing I did at the axle end of the trackbar, in order to run the Clayton HD Bolt and bushing kit. Then I'll put some real torque on it and nail that sucker in place. Oh, I'm also upgrading the joint at the bar from the bushing to a Currie Johnny Joint.

Vince
January 2nd, 2018, 16:15
Also, I balanced the wheels on all my vehicles myself. I know the balance is dno.

Also, running Centramatic balancers, so they are actively balanced during use. Balance is absolutely not the issue

If you have balanced the wheels with mounted tires then it should be OK to eliminate the Centramatic balancers from the fault finding process by not fitting them to the Jeep. Put them back on when you have found the root cause of the problem.

My wife's Wrangler had a tire carrier oscillation that I refused to believe was caused by an out of balance tire. After months of her complaining I finally considered that perhaps airing up at a gas station that had oily compressed air may have caused the balancing beads inside the tire to clump. I had all five tires demounted and the balancing beads had stuck hard in fixed spots inside the tire. I vacuumed out the tires and balanced them with conventional rim weights and the problem was resolved.

MJR might remember the same thing happening on his Jeep before we set off for the Rubicon many years ago. It's easy to believe something is working as expected, much better to prove it is by elimination.

burntkat
January 3rd, 2018, 18:52
Long since done. They work perfectly on the ZJ, they aren't the issue. I took them off and can hear the shot moving inside.

BenWheelin
January 4th, 2018, 07:00
I also saw a tiny bit of movement at the brand new IRO track bar system's frame bracket joint. IE: the bushing there moves just a tiny bit. I feel it shouldn't move at all.

It came from the factory with a bushing which deflected a little, I don't think that's it. I also don't think an expensive stabilizer is any better than a cheap one in terms of initial performance. Have you tried driving without it? See if it gets exponentially worse or stays about the same.

I just crammed pipe spacers in mine and some cheap bump stops from amazon for a four inch lift. Bolted the same shocks back in, and it drives fine on the street. This should not be an expensive adventure.

burntkat
January 4th, 2018, 09:55
I did much the same with the initial lift on my 90. I agree

burntkat
January 14th, 2018, 15:57
I pulled the IRO bar out and installed an old RE bar I upgraded with a Johnny joint. This is not to speak ill of IRO, I just happen to have the spare bar laying about, and a JJ that fit it. Installed and all the motion in that system is gone.

But now it is apparent that every one of the parts house brand, brand new tie rod ends has a little bit of play. I'm ripping them out and returning them, will install Moog brand parts as well as the V8 ZJ driver side tie rod setup.
I still have Moog ball joints to install, just haven't gotten to it yet. It's freaking cold here (30 degrees) which some of you play in, but I'm a southerner and not wired for this crap!

Will check ride with the new track bar setup tomorrow, and report findings.

burntkat
January 15th, 2018, 21:30
Check ride went very well. The majority of the DW seems to be gone. There is still some, and I know that will soon be too much if I let it go, so the hunt continues.

Toward that end, I'm replacing all the parts house brand (Master pro) tie rod ends with Moog parts. Also doing the V8ZJ tie rod upgrade while I'm at it. I got all the parts off of Amazon for $220. Considering that one of the same parts alone (long side tie rod end) is $120 alone locally, that's a significant savings.

Parts are expected by the 18th (Thursday). Weather looks to be good this weekend, and the JJ for the IRO trackbar should arrive tomorrow. I already have the V8ZJ tie rod upgrade for the wife's 94 ZJ in hand, so anticipate a lot of front end work on both trucks this weekend. Ironically, her ZJ has *massive *play in the tie rod ends and yet is silky smooth up past 80mph, with a 3 inch lift and factory trackbar. I just replaced the TREs on her ZJ last year with parts house bits, too. They have gone to shit in a year, and the ones I just put on the 97 XJ already have noticeable play. Lifetime warranty will be claimed - and cash refund only, please and thank you. I'm only going to use Moog front end parts from here on. Lesson learned.

burntkat
February 15th, 2018, 13:13
Just an update: Dodged rain and cold a few weeks ago and replaced all the MAsterpro TREs with Moog, as well as the V8 ZJ tie rod upgrade. Did a very cursory alignment.

The truck tracks true now with only a rare instance of light DW. I haven't been able to nail the alignment due to weather and my son's work schedule. Hope to be able to this weekend , and put in the front receiver hitch. Hopefully, the DW issues are completely resolved thereafter.