Problems with 4WD high

[Paytondemarco7]

Recently went trailing in my Tj, and was using 4 high most of the time. Took a little break and got back into the jeep, went to put it into 4 high again and as I started accelerating a grinding noise began to happen and the jeep wouldn’t move. 4 low works perfectly and everything else. Just 4 high seems to be messed up. I’m not very familiar with anything mechanical when it comes to stuff like this. Any ideas?

 

[LieutenantJohnson]

This sounds like your Tcase shift linkage needs to be slightly adjusted. Try driving the jeep and gently pull up/down slightly on the lever when it is grinding. See if the noise goes away. IF so, it is just slight out of adjustment and not fully engaging.

 

[Paytondemarco7]

This sounds like your Tcase shift linkage needs to be slightly adjusted. Try driving the jeep and gently pull up/down slightly on the lever when it is grinding. See if the noise goes away. IF so, it is just slight out of adjustment and not fully engaging.

So start out in 2wd and then try to put it in 4 high while I’m driving?

 

[Thunderhead]

Yea you want to be rolling slowly to mesh the gears when going from 2wd to 4wd Hi and Low, ( rolling, trans into N, pull the TC to 4h)

 

[Paytondemarco7]

Yea you want to be rolling slowly to mesh the gears when going from 2wd to 4wd Hi and Low, ( rolling, trans into N, pull the TC to 4h)

Thank you, I’ll give that a shot

 

[Thunderhead]

Thank you, I’ll give that a shot

Also, you can shift on the fly from 2wd to 4hi up to 55mph. I’ve shifted from 4 hi to 2wd on the freeway doing 70. Forgot to shift out
4 low is where you want to be going 2-3 mph

 

[Paytondemarco7]

Yea you want to be rolling slowly to mesh the gears when going from 2wd to 4wd Hi and Low, ( rolling, trans into N, pull the TC to 4h)

Thank you, I’ll give that a shot

Also, you can shift on the fly from 2wd to 4hi up to 55mph. I’ve shifted from 4 hi to 2wd on the freeway doing 70. Forgot to shift out
4 low is where you want to be going 2-3 mph

i tried the rolling idea but when I was pulling up on the lever, it still started grinding.

 

[LieutenantJohnson]

So start out in 2wd and then try to put it in 4 high while I’m driving?

yup. Maybe find some wet pavement OR dirt road to be safe. Shouldn't be engaging on DRY pavement.

Once you shift it to 4HI, if it is still grinding or sounds like it hasn't engaged, just gently pull up on lever to see if sounds go away. You can also detach your shift linkage to the Tcase and manually switch to 4HI on the case, and eliminate shift linkage completely to troubleshoot

 

[Jerry Bransford]

Know too that for offroading, you should be in 4Lo, not 4Hi. 4Hi is more for uses like snow-covered roads or perhaps if you're trying to get through deep mud or sand and need more wheelspin. For typical offroad use, 4Lo is what you want to use.

 

[Thunderhead]

Thank you, I’ll give that a shot

i tried the rolling idea but when I was pulling up on the lever, it still started grinding.

If it was your TC shifter binding I don't thing it would grind your gears.
How where you able to get it in 4 Low ?
You put the transmission in N correct before trying to pull on your transfer case lever yea ?

 

[Thunderhead]

Know too that for offroading, you should be in 4Lo, not 4Hi. 4Hi is more for uses like snow-covered roads or perhaps if you're trying to get through deep mud or sand and need more wheelspin. For typical offroad use, 4Lo is what you want to use.

I don't think he is rock crawling just yet, more FS roads it seams like
What would cause that grinding? Seems like something is off (procedure wise)

 

[Jerry Bransford]

I don't think he is rock crawling just yet, more FS roads it seams like
What would cause that grinding? Seems like something is off (procedure wise)

I'm not talking about rock crawling, just normal unpaved offroad trails. So far as the grinding is concerned, that was addressed above and is likely it's just not quite fully in gear.

 

[LieutenantJohnson]

I am not sure if I would be encouraging someone to use 4LO on unpaved all offroad trails, this pretty low and slow. I would use 4HI when traveling down dirt FSRs, which I do in snow covered roads. 4LO is for when you have a steep incline that 4HI just is too high to make it up OR like the other member said, when you get onto a tighter more crawl related trail.

Man if I had it in 4LO everytime I hit unpaved roads, it would be a couple days until I got back to pavement

 

[ShaveLazer]

I had a similar issue a while back and it was my T-case shift linkage. Changed it for a cable shifter and got it adjusted and it fine now. Might be yours too if you linkage is stock, I've heard the OEM ones kinda suck.