shadowmoses

So I have the np 231 so all I have is part time 4wd. When I put it in 4H while moving it goes in smoothly but if I'm stuck and my tires are spinning, as I'm pulling the lever, right before I get to the 4h position it makes a grinding noise. And then goes in fine. Is this bad?

HEAP of JEEP

Any time you hear grinding, its not good. The problem when you're stuck and letting the rear wheels spin, is that the Transfer case is trying to lock your front and rear wheels together. When you're moving, both sets are going the same speed, so it locks in smoothly.

When you're stuck and the back is spinning, but the front is not, it will not be a smooth transition and could cause a lot of damage, depending on how fast the back wheels were spinning.

Best to hit the brake when your stuck, before switching it, to stop the back wheels from spinning or shift the tranny to neutral.

94XJAZ

I advise to Never ever shift a transfer case with the wheels moving unless they are all 4 moving at the same speed IE driving at low speed, not slipping or spinning independent of each other. If you are stuck, stop all movement, then shift into 4Hi. If your going into 4Lo, Stop, put the trans in park or neutral so nothing is spinning, then shift the T-case. Yes there are some exceptions to these basics rules but this will help keep the oily parts inside the case with the teeth where they should be. Part time 4x is a "real" 4 wheel drive, the full time or all wheel drive cases have clutches that can slip and fail, be proud of your real 4 wheel drive LOL. Also note that when shifting in or out of 4WD, sometimes the case will need to be coaxed into gear, (IE 4Hi to N to 4Lo or N to 4Lo, back and fourth a couple times to align gears)you are trying to line up a set of reduction gears, be patient.

shadowmoses

So if I just did it like twice and barely hitting the gas, what are the chances I damaged something?

HEAP of JEEP

You're probably okay... hell, every Jeep owner has probably done it more than that... I know I have. LOL

94XJAZ

I second that Heep of Jeep, The 231 is a tough case. If it still works, shifts etc. your probably fine. I say probably since I don't know how crazy you got IE people running away screaming in fear of the nasty noise coming from your Jeep or just "Grrrrzzzip" OOPS Hmmm, not good. The second, we have ALL done with different levels embarrassment,LOL. Whether it be a lack knowledge or lack of concentration etc. it happens.

All that said, if the case does not shift or is not shifting correctly (Tested on flat even ground) it is possible to have a linkage out of adjustment or an internal T-case problem.

HEAP of JEEP

That is the perfect description. LOL. In fact, I think that should be added to the FSM in the troubleshooting section.

cruiser54

Here's how the factory suggests you shift the transfer case and I've been doing this since these things were new and I worked at the dealership. Quoted from the owner's manual. The suggestions in CAPS are mine.

"To engage, shift the transfer case lever from 2H to 4H while the vehicle is moving at any legal speed". I LET OFF THE GAS, THROW THE LEVER, TAP THE GAS AND LET OFF.

4L position: " To engage, slow the vehicle to 2-3 MPH , shift the transmission to Neutral, then shift the transfer lever to the right and pull firmly rearward to 4L".

TO SHIFT OUT OF 4L, SHIFT THE TRANSMISSION INTO NEUTRAL WITH THE VEHICLE STOPPED, SHIFT THE TRANSFER CASE LEVER TO 2H, THEN THE TRANS TO D IF YOU HAVE AN AUTOMATIC, OR INTO FIRST GEAR WITH A MANUAL, AND CONTINUE ON.

Revised 11/20/2014