I have an 86 4Runner. It snowed. I put it in 4 wheel drive. My 4 wheel drive was originally automatic, but I have replaced the hubs with manual (years ago). This means I have to manually lock the hubs and also engage the High/Low shifter into 4 wheel drive. The snow melted. I took the truck out of 4 wheel drive. Now it's got an issue. Instead of the 4 wheel drive (indicated by the dash light) being off in the neutral gear, the light now goes off when the shifter is in H2. And what sounds like maybe the rear differential is making crunchy noises, like it's not fully disengaging in 4 wheel drive or something. It was working fine before this snow storm, no issues. It was in 4 wheel drive for about a week.What is causing this? How can I get it to drop back into neutral/2 wheel drive? Is it bad to drive it with the crunchy noise? I got places to be (but also don't want to be partly to those places and not make it). FYI The crunchy noise is sort of intermittent, when starting from a stop and going slow it is most noticeable. At higher speed it disappears, or maybe I just can't hear it when I go fast. Who knows?

 

With the tcase lever in H2, the truck is not in 4WD. I never really looked that carefully at my 4WD light to notice if it goes out between L4 and H4 (which is where the N position is), but maybe it does I really don't know. The light is really just telling you what position your lever is in, so if your level is in H2, the truck is NOT in 4WD.

Now, if you happen to leave your manual hubs locked in, while driving around in tcase H2 position, the fact that the front wheels are spinning on the road, and you are making turns and whatnot, the CV axles are absolutely spinning and twisting and probably making popping and grinding sounds if they are old and worn out. So are your manual hubs unlocked? That would be first thing I would check.

 

Thanks for the reply! Maybe I remember incorrectly and the light was off in H2 before. So you are saying, that if the transfer case is set to H2 as long as my hubs aren't locked it's not 4WD? Doh! I just googled and see that H2 is actually "High Speed, 2 WD mode" which makes total sense. So only L4 and H4 are 4WD modes. I have had this car forever. You'd think I would know that by now. Doh!
With the crunching noise, I did not leave the hubs locked. I checked that multiple times and set and unset the hubs off/on to see if that was the issue. The front end makes no noise. The noise is from the rear. Interestingly, with some driving the crunching has faded and gone away. Right now I'm going with the theory that something was a little bound up (maybe in the transfer case?) when I released the 4 wheel drive which with some driving around dropped back into place. Not the best theory, but no noise is a good thing so I'm just chalking it up to old car issues. I'm thinking about if there is something else I can lubricate or change fluid in that could help if it was a binding issue on 4wd release. I dunno? Any ideas on what would cause crunching in the rear that would magically resolve itself? lol

 

Well nothing I could think of in rear that would have anything to do with 4wd. Potential sources of crunchy noises.....rear diff, rear axle bearings, possibly rear brakes, dshaft ujoints.

 

These are good ideas. I'll check them all for wear. I hope it's not the rear differential. I just had that rebuilt a couple years ago. Wasn't cheap! Thanks for the help!