PatriotGT

99GC Ladero 4wd with select trac.
I've had this thing for a little over 3yrs. and have been trying to
figure out why it's so hard to keep it between the lines.

So far I've changed the rear 3 ca's (including the balljoint) Replaced the
entire front axle assembly (the original one was shot and had the wrong gearing) with one from a jy (CA bushings looked/felt great), both tie rod ends, trackbar and steering box, 3 different set of shocks and been to 2
different alignment shops, just to have everything checked. The last one changed out the steering box. And it still handles the same.

Can't find any underside damage. This thing really gets on my nerves at times and sometime scares the crap out of me driving between any two vehicles. Any suggestions on what else to look at or have checked out?
Oh, forgot -- new tires also. Same affect.
I've got a local shop researching it for me also.

Thanks, Larry

dave1123

You might try adding more caster to see if it helps. Factory setting are "ballpark" for most applications. More caster should help and not be hard on the truck. Also make sure your toe-in is correct. I know, you got it aligned! This doesn't mean it was done right!

Also, why was the front end the wrong gearing? Has the rear end been replaced before? If the front was "original", the rear must have been replaced.

My 2000 WJ is touchy about going in a straight line also. If your attention wanders, the truck will also. I've been thinking about adding another degree of caster to it, but haven't yet. On a crowned road it will drift to the right every time. It seems to be worse in 4WD.

MY Chevy K10 had leaf springs up front and the caster was "built in". It could be changed with taper shims under the spring pads, but when you let go of the steering wheel, it spun back toward center pretty quickly. My Jeep doesn't do this. I think it could use more caster. With power steering, it shouldn't take more effort to steer it.

This is all just my opinion, mind you.

PatriotGT

yea, originally the truck had 373 gears and I'm guessing the rear went out and
someone put in a 355 axle (took me a little while to figure out why I was having
such a hard time with the 4wd until I noticed the tag on the original front axle.
Pretty sure the shops knew what they were doing, as far as alignment.

Mine seems to do a little better in 4wd than 2. I'll drive it like that quite offen.
Thinking about driving another just to have something to compare it to.

I'll talk to the shop about adding a degree of caster to get their thoughts.

does you WJ sit level? Mines 2 - 3" higher in the back. I'm thinking maybe they put the wrong springs in when they (PO) changed the rear. Maybe not.
Thanks

dave1123

It's possible they put the upcountry springs in it when they did the rear. They will give about a 2'' lift. I'm running General Grabber AT2s (245/70R16s) and they are close to rubbing. I thought I'd go with a 2" lift for more tire clearance. My WJ looks like it's sitting higher in the back but it's really not. Maybe a 1" difference. If you load it up, it squats a little. I put 600 lbs. of newspapers in the back and the 4.0 doesn't like it at all. I'd like stiffer springs, not just taller ones. Maybe gas shocks would help all the way around. (all 4) IDK.

Am I rambling? I'm tired. Sorry.

GitRDunn

My 96 ZJ wanted to wander around. Even tried to tighten up the steering box. I had General Grabber tires on it 235 70 15. Tire place rotated those tires and cross rotated and still did it. Not sure if there were issues with the belts. I put on Kumho tires 235 75 15 and still noticed it. They didn't put enough air in tires. I put in 40 lbs and the issue went away. Weird I know.

PatriotGT

Haven't checked tire pressures (with everything else I've done, you'd think that would be first on the list. KISS) tires are wearing like they should.

dave1123

Radial tires DO have very flexible sidewalls and I wouldn't surprize me to learn this is the problem. Back in the 60s, when people in the states first started using radials, it was discovered that the sidewalls are thin and you DON"T want to scrub a curb with them because they cut thru very easily. Also, when cornering, the wheel rim turns at a greater angle than the tread. When the limit of traction is exceeded, the tread snaps back thus starting an uncontrolled spin. Modern tire construction has improved some of these traits but inflation pressure is critical to performance. I used to autocross my Camero with BFG low profile radials on it. The tech inspectors wouldn't let us drive without at least 40 psi in them. This did limit traction, but chances of a rim seal failure were decreased.

Try going to 40 psi and see if it improves your handling. With today's steel belts, I doubt 5 psi will change the wear pattern. I'll try it with mine.

You see! that's why this forum is so good. It forces you to think out of the box, as some people say.

PatriotGT

Sorry it took so long to get back (been driving my Eclipse - 30mpg, but no air. now back in the GC)

I checked the tire pressures and they were already at 40psi, so I dropped them back down to 35. Not really sure if it helped, but kinda feels like it did a little, but the ride
is not as harsh as it was. I'm thinking about replacing the tires shortly, so any advice on what tire and size to go with? Currently running BFG's Long Trail T/A Tour P255/17.

dave1123

Okay, I checked caster specs for the WJ. It's supposed to be 7* (6.5-7.5*). I believe my Chevy truck was 5* but I'm not sure on that. It was built in with the leaf spring setup.

GitRDunn

2 things.

My 96 ZJ GC has caster that is out by about 1-2 degrees. It would require new offset ball joints to correct. Plan to correct after I have the money to get the head redone.

The other is a tire shop told me on those wider tires sometimes they will ride the ruts in the road and can make it pull to one side or the other. Is yours going everywhere to both sides or just to one side?

Another item I have been reading about is the control arm bushings. There are sets in the back and front. Is it true if those are rusted out and go bad they can cause inconsistent issues as well?

and as far as the tire pressure goes I have Kumho tires and max pressure is like 45. The door suggests 36. But that 36 was for size 225 15r 75 from 1996. Not sure what the max tire pressure was back then. Now I have 235 15 75. Hard for me to believe that the newer tire with higher pressure is going to wear and ride correctly with the lower pressure. Please correct me if I am overlooking something.

dave1123

The CAMBER is controlled by the ball joints. The CASTER is controlled by the cams on the lower control arms. Camber is the relationship of the tire to the pavement, wheither it's vertical or not. The caster is the angle of the balljoint centerline to vertical, front to rear. That is, the axis that the wheels turn on. The more caster, the more the wheels will want to return to straight when you release the steering wheel.

On cars with independant front suspension, when the tire moves up into the wheel well, the bottom of the tire moves out away from the body. On jeeps, the camber is fixed, controlled by the live axle. The only way to change camber on a jeep is with offset ball joints.

On lifted Jeeps, they often require extended control arms to get the caster back where it should be.

If your CAMBER is off, you might want to check your hub bearings.

The 45 psi marking on the tire is MAX inflation pressure. The difference of 10mm in width shouldn't change the recommended 36. At 45, you're probably riding on the center of the tread and THAT"S what's causing your wander.

Hey, Patriot, I'm running 245/70R16s on my WJ and they just bearly fit with the stock springs. Late winter's snow pack loosened one of my front wheel well liners and now it rubs sometimes, even though I sort of fixed it. I didn't replace ALL the push pins.

PatriotGT

Dave, I'm running 255/70 16's only time they rub is when turning to the lock while backing into my drive. (that I've noticed). They've been on there a little over 3yrs now. Probably will drop back down to suggested largest "stock" size shortly.



oh, the sticker on my door say 33psi.

dave1123

My 2000 WJ's ONLY factory option was the 245 tire size. I think standard was 225. As you said, mine only rub at full lock and with the suspension depressed, as in driving down a steep grade and turning. The snow pack is what caused my problems with the liner. When delivering newspapers, I was constantly sticking the front tire into the snowbanks the get close to the mailboxes. I had to take off the splash guard because it got partially ripped off doing this.

I'd like to give it a 2" lift, but I'm having trouble reaching people's paper tubes as it is. I may do it anyway.

BTW, I'm running 35 psi in mine.