I've been searching for a while and couldn't come up with any answers so I thought I'd go ahead and post, sorry if I've missed anything. Anyways, my 1998 4runner is having a problem where it hops or skips when turning into the driveway or in a parking lot, even when it's in 2wd. I know this points to something in the front end that is not disconnecting,forcing the two wheels to spin at the same speed, but I'm not sure what to start with.

Have you verified is coming out of 4x4?

My front end does this on sharp turns because my mud tires are already worn. You turn and the tire cambers causing it to ride on the edge and slip if road is icy or sandy.

I haven't checked yet, besides spin in the tires in gravel, is there abother good way to check? Like if I jack up the front end would I be able to tell if I spin one tire?

You can tell 4WD is disengaged without jacking up the front tires. Just reach under and try to turn the front driveshaft. If the ADD is disconnected, and the transfer case is disengaged, then the front driveshaft should be able to turn.

If it won't turn, something's up. Then you'd need to jack one front wheel up and see if it can turn or not.

At this point, I'd guess that two things are possible:
- it's still in 4WD
- the front diff spider gears are jammed somehow(?) and even though it's not being driven by the driveshaft, the left and right sides are fighting with each other.

Does the 4WD light go on and off? If it still does that it would be even weirder - because that light operates on a couple of mechanical limit switches - the transfer case and ADD both have to physically move to make the light go on and off.

Okay, I'm in school now so I'll try to spin the drives haft when I get home. Just a few days ago I had it jacked up to replace the starter contacts and the struts, and I was able to turn one wheel with the other being on the ground. And there's no light on, it'll come in normally when I shift it into 4wd, but it turns off normally when I shift back into 2wd.

We got a bunch of snow yesterday, and I know for sure it is not stuck in 4wd. I haven't been able to check if it has been hopping and skipping still with all the snow and ice, but I'll try and find a clear parking lot to see for sure. Is it possible that changing out the front diff fluid would help at all?

Snow and ice are perfect - are you getting understeer when you turn tightly on ice? That would indicate that your suspicion is correct and your front diff isn't diffing. If you turn tight on ice and you still get the hopping and you don't get understeer, it's more likely to be a suspension issue.

sounds like its not disengaging the 4 wheel. that's what my truck was doing...

first check your wheel alignment... it could be way out of wack.

See that's what is weird because when I turn on snow and ice it does do the hopping thing, but it also seems to understeer a little as well. But then I drove over to a clear are and it hopped just like it had been, maybe just slightly better than it was a few days ago. And I know for sure that the 4wd is disengaging, at least enough for the power to no longer go to the front wheels. Oh and I did forget to mention that there has also been a squeak up in the front that starts as I come off of a stop, and changes pitch and speed at the same time the transmission shifts. I haven't tracked that down yet. Also I have a very loud whirring/scraping noise you can hear throughout the car when I lift off of the throttle that has slowly become more apparent even when I have my foot on the gas. I'm like 90% sure it's the rear axle though because I jacked it up one time and put it in drive and the rear end just sounded absolutely terrible. I just thought I'd mention those two things in case.

maybe you should put it on 4 jacks, put in 4wd, and 1st... go to EACH wheel and listen for dmg/issues... then put in 2wd and test again.

Alright yeah I think I'll have to do that. I'll try and pick up some extra stands this weekend and check it out. Thanks!