Grinding when going into 4H and 4L

[hotcorner216]

So my 86 m1009 is my first off road truck, Is it normal when shifting into 4H/4L there is always a little grinding sound? I stop the truck, put it into neutral then go into 4H or 4L, and if I am in 4L and I try to put it into park after its engaged it makes this awful grinding so I have to keep it in drive, neutral or reverse. If I "wiggle" it just right I can get into 4H without any noise but not 4L. When i purchased the truck about 8 months ago the previous owner said he had just had the T case rebuilt, maybe he didnt do it right? (Truck DOES go into 4x4, I use 4x4 it 1-2 a month at least)

Oh truck is stock mechanically.
Thanks

 

[porkysplace]

Proper engagement procedure is covered in the -10 TM .
TM9-2320-289-10.pdf
TM9-2320-289-10 Operators manual for all variants of the CUCV.

 

[hoplite666]

Hubs locked? Shift on the fly can only be performed when the hubs are locked otherwise grinding will occur. That should only apply if the truck is in motion, so if you're at a stand still, and in park/neutral there should be no grinding (hubs locked or free). Either way, try locking the hubs before shifting and see what happens.

 

[doghead]

Follow the instruction on your sun visor.

 

[hoplite666]

Follow the instruction on your sun visor.

or that.

 

[Gripy]

Follow the instruction on your sun visor.

If it's still there.... You could stop and turn the engine off when putting it into 4L.

But 2H to 4H shouldn't grind.

 

[doghead]

If it isn't there, read the operators manual.

 

[Skinny]

That is because you are going from 4H to 4L while moving which is always going to cause a small grinding if creeping along. Not really bad but certainly creeping is easier than at a full stop. If fully stopped, if you go to shift into 4L and you pause to long in the middle (N position), you are allowing the trans output and tcase input to spin up. Your transmission is in gear so naturally they will spin if you spend too much time in tcase neutral territory. Now if you put the trans in neutral she will shift easier.

The best way to shift those NP208's along with anything that has a chain drive case is slow speed roll, shift trans to N, shift tcase to 4L, then shift trans back into D. That is the safest and easiest way unless you are a really good gear jammer. Then you can get it without shifting the trans out of gear.

If it grind going into park, just shut the truck off and return it to Park position.

You should get real familiar with your manuals, check out the TM's. Of course I will say that as if I wasn't riding on a high horse.