Found out my problem I posted from a couple years ago was a bad TCC solenoid that I accidentally got an extra year out of when I had me transmission fluid changed. It got replaced about 2 weeks ago. I also have very badly worn struts but I have to wait until my next paycheck at the end of the month to replace (those are expensive!) and while I was parked waiting for my son, I decided to try an see if my jeep would be less squirrelly in 4W drive. OMG what a mistake!!! The 4 wheel drive engages but the car runs horribly. Control is shot to shit and I try to put it back into 2W drive. No good and the car seems to be running some sort of hybrid 2 wheel drive and 4 wheel drive. I take surface streets home not going over 50mph just trying to make it home. Note that it is not in limp mode. About 10 miles into the Mr Toad Wild Ride I hear and feel a loud THUNK out of the back below the car and the jeep starts riding as smooth as you please. No problems today except the poor handling because of the struts.
WAG it went back into 2WD mode, either disengaging normally (whatever stuck got unstuck), or something else broke and accomplished the same thing. May or may not have caused metallic bits to circulate around with some lubricated gears.
And that is why you don’t use part-time 4wd on dry pavement.
What you just experienced is called transfer case binding. When you have it in 4wd, there’s no way for the transfer case to accommodate the fact that the front and rear of the car are moving at different speeds in a turn. On slippery road surfaces, that’s no problem because the wheels can just slip a little, but on dry pavement you’re putting an enormous amount of stress on the transfer case components. Among the myriad of bad things that can happen, the gears in the case can get locked together and so the actuator motor that’s supposed to put it back in 2wd doesn’t have enough oomph to move them. If you had an old 4x4 with a stick-operated transfer case sometimes you could break it loose with a good kick, but you don’t have that option on an electric-operated one.
Hopefully the horrific clunk was just the transfer case gears unbinding and dropping back into 2wd and not a driveline or something internal in the transfer case breaking. Have you tried putting it in 4wd since? (Somewhere that’s not dry pavement.)
Not SOLID pavement… Road surface has ^^^^^^^ texture, tyre has ^^^^^^^ texture… in the mm scale… They grip because of the dips and bumps just as much as surface to surface friction (friction occurs due to texture at the micron scale, but well thats as smooth as glass … )
4WD HI or LO? And part-time or full-time? If it was LO or part-time, it sounds like drive line wind up just as GreasyJack suggested, and you may have damaged or cracked your transfer case. It would be a good idea to get it looked at, just in case.
If it was in full-time mode, it couldn’t have been transfer case binding and suggests another cause.
[QUOTE=GreasyJack;18360447
Hopefully the horrific clunk was just the transfer case gears unbinding and dropping back into 2wd and not a driveline or something internal in the transfer case breaking. Have you tried putting it in 4wd since? (Somewhere that’s not dry pavement.)[/QUOTE]
God no! Can’t take the chance of not having a workable car. I will test it out before the icy season.
If the transfer case cracked, you’d have a big puddle.
Diagnosing whether it was just the transfer case binding up or if something’s broken will be as easy as putting it in 4wd and seeing if it still works (and doesn’t make any horrendous noises.) At least checking that it’ll go into and out of 4wd while you’re parked would be a start.
As someone who has done a lot of terrible things to a lot of 4wd trucks, I will say I’m fairly confident you just bound up the transfer case. Not the nicest thing to do to your rig, but it should be fine. Just try not to do it again.