888

Hi all, I just picked up a 98 Laredo part time 4WD with the 4.0/automatic from a long time co-worker. He has 3 or 4 of them and this one cycled out of the fleet after 8 years because the AC quit and the headliner messed up his wife's hair. I offered him a little more than he was going to get on trade-in on a newer JGC because the Jeep was straight, I had heard good things about the straight 6, and he takes pretty good care of his cars. I have a three page list of chronological repairs delivered with title and I started going through that last night after driving home (30 miles). I see a lot of maintenance such as transfer case oil change and a transmission rebuild around 40k ago, and a stabilizer replacement.

I've spent some time reading the links about "death wobble" after driving it home. The last true 4WD I owned was a Scout back in 1985 so I didn't expect the Jeep to drive like my Jetta TDI but I expected it to drive a little better than my 92 Cummins 2WD with 300k miles, but it doesn't. I'd like to describe what it drives like and ask you guys to tell me if this is the Jeep version of death wobble. I always defined that as what happens when you go airborne briefly and land with the front wheels slightly turned or catch a crosswind unexpectedly and overcorrect, something where you get a good twitch that scares the hell out of you and makes you think the back end is getting out from under you.

This Jeep seems to want to hunt constantly and relatively consistently for the edges of any ruts in the lane you are driving in. It takes a decent amount of corrections to keep it straight and they are not gentle corrections. I know the PO said he adjusted the steering box and it's not that there is play in the steering, it is that the front end wants to chase the road a lot more than it should. That's one problem.

Another problem, I occasionally get a thunk up front when going over bumps, but not always. Sometimes I get a nice quiet dampened sound but not always.

Finally, I get what I would consider a loud humming vibration from the front end, I only really noticed it at around 50 mph. I gave it a gentle swerve to see if it changed with loading like a wheel bearing would do but I did not hear any difference.

Shocks are relatively new as are the tires, the tires were recently rotated and the tread seems even and there is plenty of it on all tires. Tires are Firestones, not a real aggressive pattern, maybe Wilderness AT's? The front end seems to react immediately to the steering wheel, no lost motion.

The PO had a local place that does the maintenance on the Jeep test drive it awhile back because of the steering and they said "that's just the way a Jeep drives", that was when he went home adjusted the steering box. I understand it's a worm gear type with a locknut and set screw for adjusting play.

I've had 100+ cars and usually do a lot of my own work but as I mentioned, this is the first 4WD I've owned in a long time. I was wondering if the 3 problems noted above added up to anything specific and if what I am seeing out of the front end is actually death wobble or something else. People seem to get death wobble from mechanical play up front and if anything, the front end on mine seems too tight. It has 172k miles, and i expect someone will highlight that and tell me the front end may be worn out, but play doesn't seem to be the issue, not yet anyway.

I have picked up on the fact via searching on here that the stabilizer wearing out is usually masking other problems, I believe the track bar is usually a prime candidate. I plan on jacking it up and seeing if anything is loose or obviously wrong. I'd be inclined to get an alignment but if something is wrong up front, that would be a waste of money.

Thanks for reading all this and for any suggestions on where to look first.

Joe

888

Still looking and reading everything I can find on DW and it sure seems more related to wear and sounds kinda like a bad case of wheel hop or something of that sort. if someone could confirm that, I sure would appreciate it. Mine doesn't seem to be doing that.

Thanks

dave1123

You might want to check your hub bearings. IDK if they've been replaced, but are often overlooked. Death Wobble is usually caused by the track bar allowing the whole axle assembly to move side-to-side, thus allowing the tire angle to change at the same time. This starts a synchronous vibration that amplifies itself to the point of shaking the whole vehicle to the point of loss of control of direction.

Bad hub bearings will allow side-to-side motion of each wheel independently and cause the front end to "hunt", as in going where it wants to go. A wrong caster setting will also cause this.

The front end humming may be pinion bearings in the differential. Jeep diffs are not the strongest things on the planet.

That's all I've got. Hope it helps.

888

That's really helpful, Dave. I didn't see hub bearings in the list of things replaced and bearing noise was what I thought I heard but it didn't react like a wheel bearing would on what I usually drive, a FWD VW TDI. I thought that the Jeep seemed a little gutless, like it was fighting itself a little, and the PO said it got worse mpg than his V8 JGC, all of which could indicate a problem with those bearings. Or maybe it's just a 6 cylinder moving a lot of weight, I've never driven one so it could be normal.

Do you have a suggestion on where to buy some good quality replacements? I read a post somewhere in my researech that said they weren't all that hard to change, they actually came as a hub and bearing assembly, IIRC.

Thanks for the reply.

dave1123

I personally buy from rockauto.com and have ALWAYS had good luck with their parts. They usually have different choices of parts.

I've changed the hub bearings on my ZJ. There are 3 bolts holding the assembly to the spindle carrier. They are designed for a 12 point socket only. The hardest part was the axle nut. I had to buy a socket for that and use a long 1/2" breaker bar. Be sure you torque this nut properly on re-assembly.

I just checked rockauto. I personally bought the Raybestos ones for $55 each. The cheaper ones are just as good.

888

Thanks for the reply. My son plays HS soccer and I just remembered one of the other parents has a fleet of GC's that he is constantly modifying so I asked him last night about the hub swap. He told me about the axle nut, it should be a 36mm? I just borrowed a 3/4" drive 6 point and 1" drive 12 point 36mm socket from the shop tool kit, I forgot which 12 point is required, do you know offhand?

Eric M

The 3 bolts holding the hub to the knuckle are a 12 point 13mm, or at least they were on my previous gc and my current tj. While you have everything apart take a look at the cv boots, if they are torn I'd recommend replacing the shaft if they are cracking you can replace the boots.

888

Thanks for the reply, 13mm sounds right.

The more I read and look at the service history of the Jeep for the last 70k miles when my friend owned it, the more inclined I am to pick up a track bar on general principles to fix the wandering. It is either original and has 170k or has at least 70k miles on it so it probably needs to be replaced anyway.

dave1123

Good point on the axle joints. My 97 was u-joints. These are easy to replace and it wouldn't hurt to replace them while you have it apart. The u-joints are cheap. If you're going to replace the track bar, get a polyurethane bushing for the axle end. It has less flex and will last longer, however if the original lasted 170K, what's the point.

888

I recall seeing U joints on the list of things replaced by the PO but I will check them regardless as part of the process.

The more I think of this, the more I think i have two problems, wandering and noise. The track bar seems to be the cause for the wander so I was going to start with that and see what it brought to the party.

Thanks

888

I had to send the PO to Ecuador for a month on a project but I received an email back from him this morning that he hadn't replaced the track bar or hubs on his watch. That means they are probably original, and everything other than the U joints/shocks/stabilizer may be as well.

Bustedback

New front control arms will tighten the front end up a lot, I'm sure the bushings are soft and worn after 15 years of service. I just swapped WJ upper arms in place of the flimsy stamped steel junk that was there, a HUGE difference in the handling and ride. www.rockauto.com is the place to buy your parts if you can wait a few days on shipping. I got both of the new arms from them for less than it would cost for one arm at the local parts house.

dave1123

I hate to add to your woes, but you should check your ball joints. My 97 was getting kind of weird, so i checked mine. One of the lower joints was missing a top cover! Can you believe that? The upper ones are greaseable, but the lower ones weren't. There isn't enough room for a grease fitting because of u-joint clearances.

It was amazing the state inspector didn't catch it. Then again some just give it a quick glance and put on a sticker. My guy lets me know BEFORE he starts the inspection what won't pass. In NY, if the inspection sticker has expired, it's scrapped off before the inspection. If it doesn't pass, you have 10 days to get it to fixed. If you can't, you are required to turn in your plates until it does. It has to be towed in for the next inspection.

888

No problem, it's only a woe if I don't know to look for it. Last night I got home a little before dark so I started to lift the front end. There is a lot of travel on that front end suspension, I'm not used to lifting 4WD. I have the unibody (wood) blocked up back at the frame rail just behind the firewall and front wheels still hit the ground when I release the jack under the lower control arm point on the front axle.

I assume I should just take the load off of the front wheels via lifting the axle to do the testing after blocking up the frame. I don't know that I could get the front wheels completely off of the ground via frame blocking with the hyd jacks and wood blocks I have, times like this I wish I had a lift.

I've heard about the inspections in NY and PA. Here in Ohio, if you can get it to roll, you can put it on the road and believe me, you can tell by the bumpers and large bits that rust off and end up by the side of the road. I saw a 80's era Chevy truck yesterday on the highway on the way home from work that had been hit hard in the front corner to the point that the front wheel was laid over about 25 degrees and the truck was taking up most of the lane via tracking sideways.

dave1123

Now that's funny! I had a 79 GMC that was so rusty the box sides were flapping in the wind with just the tailgate holding it together. It was good mechanically so it passed inspection. One day on the way to work and on the highway, it suddenly felt funny, so I looked in the side mirror and the whole driver's side of the box was sticking out in the wind! When I started to slow down, it ripped off and sailed thru the air, landing in the medium. I kept going! I almost wet my pants laughing. When I got to work, the tail lights were still there and working. I drove that POS for another year and then replaced it with an 83.