Front diff questions

[99BurbK15]

Well some of you may know that I had problems with my front differential in the past. When I had the vehicle in 4 Hi or 4 Lo and turned to the left or right there was a loud clunking/banging coming from the front. So since I am still in high school I had my shop teacher look at it and did in deed say I needed a new front diff. So he referred to a guy that he always goes through and got a nice diff for $100. So we put it in and never really got to test it. So we had our first snow storm here in Wi on Sunday and went to try it and the front diff wouldn't engage so after further research the problem was the washer that goes between the stub shaft in the case and the output shaft that goes to the CV joint. (I hope that makes sense) That being said my instructor and I took the axle tube off and inspected the gears and everything was okay. What happened was the washer slipped between the 2 shafts and wouldn't let the collar fully engage. I got all that put together and went to test it tonight and the same clunking/banging noise when turning...WHAT THE HECK??? So I think it is the front actuator but don't want to spend that kind of money unless I know for sure it is the problem. What else could it be???

Also when I went to put it in the shed tonight and tried to take it out of 4 Hi and my push buttons went black so now my Suburban is stuck in 4 Hi. The front diff, thank heaven is unlocked but not the T-Case. I checked the fuse in by the door but all good.

The Suburban only has 182K and had the T-Case replaced in 2014 (NP246). All this is do because the previous owner used 4 auto a lot.

Please let me know where I can start. Thanks to all in advance! Ben

 

[99BurbK15]

Well, I went out after supper to play with it and learned why my buttons wouldn't work, my T-Case (20A) fuse poped so I pulled the old one out and as soon as I put a new one in it poped? So does that mean the transfer case motor is bad?

Please let me know, I am willing to try just about anything at this point. I am at a completely lost.
Ben

 

[99BurbK15]

Wow I am surprised no one replied back yet. I have another question, Is there a way I can manually shift the transfer case it out of 4wd for now? If not is it okay to drive with it still engaged? The front diff is ungaged just not the transfer case because I can crawl under it and is locked in place. Thanks

 

[83GMCK2500]

Do you still have actuator on front differential connected? If so, unplug the actuator, replace fuse and see if it still blows. If it blows, unplug the encoder motor on the transfer case, replace fuse and see if it pops. Should give you an idea which one is shorted out. You can unbolt the encoder motor, remove it, exposing a short shaft that you could manually turn. I don't know which way it would need to go for 2 HI, the position it is in now may be the extent of one direction, it could only be one click from 2 HI.

 

[99BurbK15]

Thank-you very much for your response. I did what you said and believe the encoder motor is the issue but with it unplugged I can put a new fuse in and a silver box under the dash clicks like 3-4 times and the lights in the push buttons stay black. So with that being said I crawled under it, removed the encoder motor, shifted it to 2 Hi no problems and went to put the motor back on and the shaft wouldn't line up with the groves in the motor. I tried to move the motor but didn't budge so I just kept it off for now. Is that okay to do? I won't damage or hurt anything with it off right? I assume it's just like a manual case now. Thanks, Ben