Transfer case grinding

[Faris]

Hello everyone

First of all, I appreciate this amazing community.
I have a GMC Jimmy 1984 with an LQ9 swap, 4L60E transmission, and NP241C transfer case with passenger side VSS.
The transfer case has been rebuilt and swapped from a 32 to 27 spline input shaft.
I cranked it up last night, and it runs well. With the t-case in 2H, I put it in gear all good. While cruising, I slowed down, then started hearing grinding, and the car was moving in neutral. With the lever in 2H, if I try to shift to park, it grinds.
I tried to pull the lever to 4H, but there was more grinding, and it didn't work. I put it back in 2H, but it was still grinding.
Then I tried to pull the lever to 4L, and it worked! I tried to get it back to 2H, but it didn't work, so I pulled it to 4L, then shifted to reverse and moved for a distance. Then I tried to put it back to 2H, and it worked!
Also, this issue appeared when I was off-roading. Sometimes it did not shift back from 4WD to 2WD easily.

Is this normal? What could be the cause, and how can I fix it?

 

[Wes Harden]

Welcome to Ck5.

Difficult shifting tcases, I am sure everyone here has a story.

Driving in 4wd on hard pack can put a bind on the t case. While stopped turn the steering wheel back and forth afew time to elevate the binding,then select 2wd.

You should double check the shift linkage adjustment, your description makes my think the selector is between gears.

4wl is always difficult, at least in my rig. I need to stop and place my trans in park to go in/out of 4wl

 

[sweetk30]

When my 208 died it would only move in 4low .

So something is wrong inside for sure .

 

[Blue85]

Anytime the T-case is in neutral, and you shift to park, you'll get grinding from the parking pawl. This is inside the transmission, which turns a little bit even when it's in neutral. The only way to avoid this is 1) shut the engine off or 2) have the transfer case in gear.

As for the T-case problem, the first thing to check out is the shift linkage. Maybe it's not quite pushing it into gear. You can disconnect it and shift the lever on the side of the case manually to know for sure. There is an adjustment procedure you can look up. If that's not the issue, you probably have worn shift forks in the case or something was assembled wrong.

 

[Fastereddie]

You want to shift the t-case with the transmission in neutral. If you’re trying to do it with the trans in drive or park, it’ll give you hell.

 

[Blue85]

While cruising, I slowed down, then started hearing grinding, and the car was moving in neutral. With the lever in 2H, if I try to shift to park, it grinds.
I tried to pull the lever to 4H, but there was more grinding, and it didn't work. I put it back in 2H, but it was still grinding.
Then I tried to pull the lever to 4L, and it worked! I tried to get it back to 2H, but it didn't work, so I pulled it to 4L, then shifted to reverse and moved for a distance. Then I tried to put it back to 2H, and it worked!
Also, this issue appeared when I was off-roading. Sometimes it did not shift back from 4WD to 2WD easily.

Did you rebuild this case or somebody else?

I had a similar experience. The T-case was fine until one day I came to a stop hard and was in neutral. Shifting to 4HI didn't work, but shifting to 4LO did and after that 2HI was fine again. Drove fine for a couple of weeks until it happened again. Tore the case apart to find that the shift forks were worn out. What I mean is not only were the teflon pads gone, but the forks themselves were worn thin. One fork shifts the "mode" which is engaging the drive chain and the other shifts the "range", which is locking the planetary set to give the low range reduction. With the thin forks, the normal range of shifter motion wasn't enough to set the sleeve back in position.

But yeah, still check the linkage first.