mike_d

I've been having a wierd problem with my '89 4runner IFS in 4wd that I've never had before nor have I read about on these forums. First the problem, and then I'll list what I've already checked out.

When driving on a snow packed, straight road up a hill or on the flat, when the truck is in 4wd it will swerve slightly to the right and then back to the left. At first I thought maybe it was just really slippery out and it was normal sliding, but after paying attention more, I could actually feel the steering wheel being jerked around. It feels like there's a little gnome in there that's grabbing the steering wheel and jerking it. The problem only happens when in 4wd and under power, that is when engine braking down the hill, there are no symptoms. Also if I take it out of 4wd (but leave the manual hubs locked) all symptoms go away.

This didn't happen last year in the snow, and the only thing that's changed is that I added the 4Crawler BJ spacers this summer, so maybe the increased CV angle is causing some problems. I just had it into the shop for some other stuff and had my mechanic check out the CVs and he said they're fine.

I just had the front wheel bearing replaced, so they're new. I checked the hubs after 2 hours of driving up and 2 hours drivng down the mountain and they were not hot or warm or anything that would suggest anything rubbing or bad bearings or something like that.

There are no noises or anything that would suggest a problem.

The problem doesn't happen regularly. That is, if it were something related to the CV or something, I'd expect it to happen every rotation of the wheel or something. This (appears) to happen randomly.

I also checked my tread depth and pressure on the tires and they're all the same, so there's no issue with mismatched tire sizes.

I also don't think it's binding or anything like that because it's pretty easy to get it in and out of 4wd. Generally when there's some binding, it's takes some effort to push the shift lever out of 4wd.

The truck has 249,000 miles on it and as far as i know the drivetrain is all original except for the rear end which was replaced at 215,000.

That's everything I could think of to check. If anyone has any good ideas I'd appreciate it, right now it's more scary to drive in 4wd in the snow than it is in 2wd.

Thanks!
Mike

Flamedx4

Really hard to tell just from a description, but..
It *might* just be that your steering stabilizer is shot. Also I would look closely at all the steering components (tie rod ends, idler arm, etc.)
It sounds like what I used to experience with a clutch-type posi in the front. But if you have an open front diff it shouldn't be anything like that.

Radical steering sucks. Erratic steering does too...

photoleif

just a rash of questions... hoping that your answers to these might help someone more knowledgeable than i.

and this doesn't happen when you're not on snow?...if the trail is dry, then no issue? how about leaving it in 4-lo in snow, but unlocking the hubs so you're in lo-2, basically? presumably then it doesn't happen either, right? do you have any sort of front locker? can you get it to do it in snow on a city street (presumably flat)?

91_4x4runner

Maybe one hub is enguaging and disenguaging? Do you have manual hubs or the ADD system?

Bobakazi

How long have you owned it? Do you know for sure what (if any) lockers you have?

Greg'sToy

a loose idler arm could cause this to happen...

live277

Check all of what flamex4 said and your alignment.I have the spacers also.If you're using stock torsions and wheelin a lot you'll find alignment is almost impossible to keep.If one tire is out and that side grabs it will go in the direction of the tire.

mike_d

thanks for all the replies. from all the advice, it seems that i should check out the steering, in particular the idler arm. is there an easy way to check if it's bad? or is it one of those things that a tech with experience can look at and just know that it's bad.

to answer other questions:
-i only have manual hubs, no ADD
-both differentials are open, the front is original, but it's hard to tell how many miles are on it since most of the time the hubs are unlocked
-i've had the truck for 30,000 miles and 3 winters, this is the first time i've ever had a problem
-symptoms appear only in 4wd with hubs locked, so hubs unlocked in 4-hi or 4-lo there are no problems.
-have not tried it on a dry road, for fear of breaking anything.

mike

Greg'sToy

hey mike- try this to see if you're idler arm is bad. jack up the front, both wheels off the ground. now grab the passenger side tire like about 3 oclock & 9 oclock, and try moving it, pushing and pulling at 3 & 9. if the arm is bad, you should see some flexing or movement especially at the idler arm. the arm should only move back and forth, not up and down. hope this helps you...

trythis

Shots in the dark

Does your steering wheel pull in the wrong direction, or does the truck just start lisitng the wrong way and you have to correct it by over steering the other way? I am inclined to think this is related to your front differential as the rest of the steering components are in use regardless of 4x4 engagement. Is it possible for a differential to cause intermittant drag on one wheel while the other is free? Have you checked the diff. fluid level in the front?

I suppose another issue is that when one of your wheels gets power from teh differential that might cause it to turn in or out seperatly if a linkage is bad. It could just be a couple of worn ball joints?

Doc279

My 1990 used to do this in the mud and the snow ( we haven't seen any snow this year ) The steering stablizer is shot

Check the steering ends as suggested though