NEED HELP Noise when accelerating, idol (until it warms up) and shifts hard from D to R and vice versa

[dr_leis7]

So about a week ago I was heading to work and got caught at a red light. When accelerating from the intersection I heard a loud grinding noise from right below me. I pulled over but couldn’t see anything, it was 3am, and since I was right down the road I busted a shitty and parked it.

I replaced the Ujoints ( was pretty sure it wasn’t them) but money’s been tight since all this covid bullshits been around.

I’m 90% sure it’s my transfer case, but I’ve never done anything on the drivetrain and wanted some information on ordering used ones and if I should check anything else out first...

thanks guys

 

[Mooseman]

Has the transfer case been maintained properly? Fluid changes are at a relatively short 50k miles. Or it was low on fluid. Did you check the fluid? It's normally blue. If it's black or has metal chunks, it's done.

Any transfer case from any year and engine TB or Envoy will work. If you have a U-Pull yard, that would be your cheapest alternative. Just check the fluid inside to be sure it's been maintained.

Edit: It could also be the transmission. I had that happen to my EXT, which sent it to the big scrap yard in the sky. I even have a video of it:

 

[dr_leis7]

Haven’t done anything other than the Ujoints. Was gonna drain and drop it tonight, but I helped a friend of mine install an ignition switch on solenoid on his boat n ran out of time. Will check tomorrow.
The transmission fluid was ok, not bright red, more of a brown. The previous owner was a lazy pos and ran it into the ground, so I doubt it was changed/checked. You would think if it was a tranny issue it wouldn’t be engaging in some or any gears, no? The only previous issue I’ve had with it was pulling out onto a country road about a month ago it didn’t switch into second. Let off the gas till it dropped back down to 30 and accelerated again and it shifted after that. Occasionally since I bought it, if I use the 4wd a service 4wd light will come on. But that’s only happened 3-5 times in the 4 years I’ve had it and it goes away if I turn my truck off than on again.
I’ll let you know what the fluid looks like in a few days. But I know I’m leaking power steering, so I’m confident I would’ve noticed a leak

 

[dr_leis7]

Has the transfer case been maintained properly? Fluid changes are at a relatively short 50k miles. Or it was low on fluid. Did you check the fluid? It's normally blue. If it's black or has metal chunks, it's done.

Any transfer case from any year and engine TB or Envoy will work. If you have a U-Pull yard, that would be your cheapest alternative. Just check the fluid inside to be sure it's been maintained.

Edit: It could also be the transmission. I had that happen to my EXT, which sent it to the big scrap yard in the sky. I even have a video of it:

Mine doesn’t sound like that. Like I said, I’m 90% sure it’s the transfer case. No gear change problems(other than that one), no whining noise, and I only have grinding when accelerating. That sounded pretty constant

 

[gmcman]

Just a thought, and not sure if this is a good idea unless you are ready to tear into it, but does it work in 4HI? Could this be a bad encoder motor keeping the engagement stuck in between modes?

 

[dr_leis7]

Just a thought, and not sure if this is a good idea unless you are ready to tear into it, but does it work in 4HI? Could this be a bad encoder motor keeping the engagement stuck in between modes?

Alright, working on it now, just drained the transfer case and it was black.... I’d have to hook everything back up, but it worked in all drives (didn’t try hi/low). I’m assuming the pump got clogged up and trashed something in the box. BUT! I’ve had it for several years, never changed the fluid in the case... so 🤷‍♂. What are the chances it just needs to be cleaned out lol... I’ll keep y’all posted, I’m working two jobs cause of this Chinese flu bullshit so when I can get to it is sporadic

 

[dr_leis7]

So about a week ago I was heading to work and got caught at a red light. When accelerating from the intersection I heard a loud grinding noise from right below me. I pulled over but couldn’t see anything, it was 3am, and since I was right down the road I busted a shitty and parked it.

I replaced the Ujoints ( was pretty sure it wasn’t them) but money’s been tight since all this covid bullshits been around.

I’m 90% sure it’s my transfer case, but I’ve never done anything on the drivetrain and wanted some information on ordering used ones and if I should check anything else out first...

thanks guys

Alright, finally got around to tearing into this bi$&h.
Honestly wasn’t to bad. Took the rear and front drive shafts off, crossmember removed, unhooked all the wires and vent hose, and dropped the Tcase by myself... no jack necessary( some people need to put down that purse! 😂, all I heard was about how heavy they are!) what confuses me is wear inside the tranny where no moving parts are... idk if some jabrony before me replaced this already or what... not terrible, but noticeable. Planning on replacing the tranny mount, front ujoint, Tcase, and Tcase seals. Would a bad mount cause wear inside the tranny housing like that? Not a big deal, just going to clean it up and move on, just found it odd.

 

[dr_leis7]

Alright, finally got around to tearing into this bi$&h.
Honestly wasn’t to bad. Took the rear and front drive shafts off, crossmember removed, unhooked all the wires and vent hose, and dropped the Tcase by myself... no jack necessary( some people need to put down that purse! 😂, all I heard was about how heavy they are!) what confuses me is wear inside the tranny where no moving parts are... idk if some jabrony before me replaced this already or what... not terrible, but noticeable. Planning on replacing the tranny mount, front ujoint, Tcase, and Tcase seals. Would a bad mount cause wear inside the tranny housing like that? Not a big deal, just going to clean it up and move on, just found it odd.

also, the old transfer case had obvious slop when rotating forward and reverse... but in constant rotation in either direction seems alright. Obviously I can’t spinit at 1000+ rpms, but was curious what y’all had to say about it. Or if you had any insight into that.