95 3500, Pops out of reverse in 4h and 2h and howls while decelerating.

[Ray Block]

My 3500 6.5 4L80 plow truck randomly pops out of reverse in 4h and 2h, It works fine in 4L. When I decelerate while in 2h at 30mph or more I get a howling noise. If I put the transfer case in neutral it stops howling. I'm assuming it is a bad transfer case and hoping its not a transmission problem too.  

[richard wysong]

Welcome to the Forum! Any oil in the transfer case? There are problems with the oil pump and case leaks with those tcs. If it is howling the damage is done so look for a used 1. I can not count how many times I have checked the oil in TCs to find them completely empty due to the case leaks. As far as popping out of reverse it makes no sense as the trans has a cable shifter so even a broken mount should not affect the shift linkage UNLESS the cable retainer on the trans bracket is messed up or the transfer case shift linkage is interfering with the shift cable

[Ray Block]

Its kinda strange that reverse works all the time in 4L and at random times in 4H and 2H. Its been like this for a while now. I mainly use it as a plow truck but will need to get it sorted out soon. I just want to make sure its the transfer case before i start the repair process. 

 

[richard wysong]

Why do you use 4 low plowing? That is how you break things! I have been plowing  45+ years and NEVER found that 4L had any advantage over 4H. I would crawl under and look at the TC shift linkage and the trans selector cable and see if they are interfering with each other

[Ray Block]

I will check the cables first. I use 4L because it wont reverse in 4H. seems like too much of a hassle to keep switching to 4L just to reverse. 

[richard wysong]

Gotcha, It is possible that something is broken in the TC but you would think it would affect going forward as well.

[diyer2]

Was the TC serviced properly? Did you change the fluid? 

 

[Ray Block]

I'll check that too. 

[richard wysong]

Bet it is dry