Hello guys, so today I decided to test my 4wd and it worked fine, in both 4 hi and 4 lo. Well, tonight I was driving, and after a while, I started hearing a noise, as if something was dragging underneath the truck. So I pulled to the side, and my friend and I took a look underneath, and saw that there was a rubber hose dragging underneath. My friend said that it appeared to be a breather because it had an end cap on it. I believe it was 7/16. It was cut at one point. So my friend cut off the bad piece, and replaced the cap on the rest of the good hose, and then zip-tied it in a place where heat would not damage it again.

Now the problem is, I arrived home, and decided to test the 4wd for a second time. I put the truck in neutral, and hit the 4 hi switch. I went forward and reverse with no problem. Next I put it in Neutral, and pressed 4 lo. I went in reverse, and the truck bounced up and down on me while moving in reverse. So I stopped, and put it in drive, and the same thing happened. Then I switched back to 4 hi, and the 4 lo light was flashing like crazy. I finally got it back to 2 hi. Then everytime I go from 4 hi to 4 lo, the 4 lo light just flashes, and does not engage into 4 lo.

I am going to my mechanic first thing in the morning tomorrow, but I wanted to see what you guys thought. Could that hose have anything to do with it? Or could it be something with the transfercase?

Also, I used a flashlight to light up my gauge cluster. I saw that there is a spot on the cluster, that says "Service AWD". Is AWD the same as 4WD? That light has never turned on ever since I bought the truck, not even when turning the ignition to the on position. Is there something wrong with it?

And one last thing, I have been having some "whir" sound with tire rotation lately. I read on a search on here, that it may have something to with the front differential being partially engaged? Just wondering cause this might all be related.

 

Can anyone help me out?

 

Have you tried the search feature?? 4wd issues are common with these trucks and a lot has been covered before.

Sounds like your truck got stuck in the transfer to 4LO. This is typically caused by a faulty or failing encoder motor (specifically the position sensor which is not independently replaceable), but there are quite a few other things that you can check first. Checks are covered in quite a few other posts...

 

im still having a similar problem with my 99 jimmy noise was coming from the front passenger wheel still have no clue what it is just replaced the hub bearing and the problem is still there. it only happens intermitently (sp?) to me and usually i have to be either on a highway or give it some juice above 35 mph.

 

Actually, the problem above sounds quite different from the problem you described in THIS THREAD second97... But that is just my opinion on the two problems. Clicking/humming and jumping sound different to me.

 

i was referring to the the whirring noise that he was getting actually

 

Ah, again I did not read the whole "edit" above. In his case though I still believe that if the encoder were stuck between gears, it could cause the front axle to stay partially engaged and cause the jumping that he experienced. Could also be caused by a sticking actuator or a malfunctioning switch, or...

One thing that the OP has not stated was whether he was ever successful at returning to 2HI...?

 

Thanks for responding to me. I have searched on here. In fact, I printed out that very helpful post, "4x4 No Worky" and used it to help my mechanic save time, rather than searching everywhere to find where the parts are located.

Ok, to clear things up a bit. I just got back right now from my mechanic, and then the Chevy Dealer. So this morning I went to my mechanic, and while the truck was lifted in the air, I sat in the driver's seat and put it into gear while my mechanic checked it underneath. It worked fine while it was in the air. I then decided to tell my mechanic to take a ride with me around the block. So I drove, and switched from 2 HI to 4 HI with no problem. Then I put it in Neutral, and pressed 4 LO. 4 LO was flashing. So my mechanic told me to put it in Park. It engaged while I was in Park. Then to get back to 4 HI, I had to put it in Neutral. My mechanic then told me that was normal, which I know is not.

So, after I left my mechanic, I decided to look through my owner's manual. I was reading, and saw that YOU HAVE TO BE IN NEUTRAL TO SHIFT INTO 4 LO. IF 4 LO STARTS FLASHING, YOU MAY SHIFT INTO PARK, WHICH WILL ENGAGE 4 LO, BUT IT IS RECOMMENDED TO HAVE IT SERVICED BECAUSE YOUR TRANSMISSION SWITCH NEEDS ADJUSTMENT.

So after reading that, I decided to go to a Chevy dealer, and showed the guy the book, and explained him my problem. After they checked it, they told me that they would have to take apart the transfer case to fix one of the pins on the inside that may have broken. They said it would've been about $400 to $500. He suggested that I leave it like that, and that by shifting into Park to get into 4 LO will not do any damage. He then also suggested that I do a fluid change on the rear, and front differentials for about $400. I declined, and just ended up paying $54 to have it checked out.

My question now is, do you also think that my problem is inside the transfer case, or do you think that it is "the transmission switch that needs adjustment" as stated in my owner's manual?

Also, would it be a good idea to leave it the way it is? Or do you think I should do something about it because it may cause further damage?

 

This is the first I have heard of something possibly being broken inside the transfer case. Typically it is electrical... What happens if you are rolling very slowly while in neutral and you select 4LO?

Typically one problem with going into 4LO can be a time out due to the gears not meshing together. By moving from neutral to park, you have shifted through reverse which will cause movement of the transmission output shaft / transfer case input shaft, allowing the gears to mesh together. Most often, the gear alignment does not have to be right on for it to slip in (often with a good clunk).

IMO, it is just operating slightly out of the norm and not something to be worried about (speaking only of the 4LO engagement).

 

I really haven't tried it while rolling in Neutral. I have always stopped, then shifted into Neutral, and then switched. If it is electrical, which could be the part, and where would it be located?