Out of 4wd Hard

Pete did pass the time by typing:

^^^^^ The first question is why are you doing this??

If you were doing it on pavement it may have something to do with your axles binding a little. There is nothing built into your transfer case to relieve the pressure that can be caused by your axles turning at slightly different speeds. Try doing the same test on a gravel road.

Ray AB9IA

o_o_o_o /| ,[_____], |¯¯¯L --O|||||||O- ()_)¯()_) ¯¯¯¯¯ )_)

She's trying to tell you to read your owners manual! You should never shift into 4wd on non-slippery surfaces (like pavement)! You'll break stuff! In addition to that, 50 mph is around the upper limit the transfer case could handle. It's a bit surprising you didn't grenade something.

Your linkage is out in the open under there and likely is full of dirt or in bad need of a grease job.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Pete wrote:

I should hope 50 wasn't the top end for a shift.

I shift in and out of 4 high at 60+ mph all the time in both of my Jeeps in the winter.

And 'both' of my owners manuals say to shift into 4x4 once per month on a straight road to keep everything lubed up and working right.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

TJim wrote:

1. It's a really, REALLY bad idea to travel on a paved road in 4Hi or

4Lo in your TJ. This newsgroup is archived on Google, go there and read some of the old posts about this.

1. Probably just hard to shift because you haven't used it much, lube the shift linkage and it will probably free up. It has nothing to do with gearing or tires, though.

2. Did I mention that it's a really bad idea to travel on paved roads in 4 wheel drive mode?

I could be wrong about this, but I don't think you are supposed to be switching into 4WD at 50 mph. I always stop first, shift into 4WD, and then go. When you switched it out of 4WD, were you going 50 mph? How does it shift out when you are stopped and then go?

-Brent Bogrees '89 Jeep Wrangler YJ 2.5L TBI ? 33x10.5 BFG AT Tires '94 Jeep Cherokee Sport 4.0L ? 31x10.5 BFG AT Tires

You can shift into and out of 4 high at any legal speed.

I just use it like any other shift. See a patch of snow coming, shift into 4 high, get to clear road again, back to 2 high.

4 low is a different story, you need to be moving 2-3 mph to get a smooth shift, no faster.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Brent Bogrees wrote:

NEVER DO THAT AGAIN.

Your tcase does not like hard surfaces, and the resulting bang is an indicator of how much it doesn't like what you did.

since I haven't used it really since last winter (been a busy

No. It is the extremely good traction that is binding the tcase that caused this.

You are right Bill, I was off base there.

I went back and read the manual and only in my CJ7 am I supposed to lock the hubs and drive it in 2 wheel drive once a month with the hubs locked to lub the front axles and bearings.

Mike

"L.W.(ßill) Hughes III" wrote:

Go back to that stretch of road where you did this and look for missing or shattered parts. The parts you find could help with the shifting issue once replaced. ;->

Actually, Brett, you can switch into and out of 4WD at pretty much any speed. the problem for the original poster is that he did it on the street, and this binds the tcase because the front and rear drivetrains operate at different speeds. The question is, if you are able to go 50, why do you even think that you might need 4WD? The idea is that if you can go that fast, you don't need 4WD to do it.

I would agree with you if only talking about 4WD LOW. 4WD High is another matter. My Subaru is WD and I have NEVER fishtailed, slid, slipped, etc on wet roads. Every 2WD car I've owned will slip and slide on wet pavement (I like watching Mustangs in the rain). 4WD increases the odds of a tire finding a non-slick surface...

Hi Jeff, I was always under the impression that if you go 4wd on hard pavement, tis ok AS LONG AS you do not do any turning. If it's a straight stretch and smoothly paved, there really shouldn't be any bind, no?

Judging by the post though, it SOUNDS like he has some bind coming out of 4wd. But my guess (just a guess ;-) is that it's just in need of some lubing.

Maybe a better test would be for him to go on some grass, or gravel, and check it that way..

Also, I think shifting into 4wd (high only) at 50 is just fine. Although I think it's in the upper end of the limitations there. I usually drop to about 40 if I'm going to do a "shift on the fly"

=Mike

94 Cherokee I6

Not around here. I want to be keeping up to the transport trucks, if they are running 60+, I will be running 60+ in 4x4 for sure!

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

That is true to the point that the front and rear axles have the same size tires (worn the same, not the same size, per se) and are geared the same (the 4.10 gearing of the rear is 4.11 on the front). These differences are small, but real. The tires can slip on the ground to disipate the resulting stresses that come from the small differences, but the stress are not disipated on the street, and they build up in the tcase, and the tcase can let go with a bang when that happens.

There will be less stress on a straight road, this is true, but that only means the bang will be smaller.

I don't think the speed has anything to do with the "problem" either, except that 4WD for 10 seconds at 20 is not nearly as far as 4wd for 10 seconds at

55, so any difference in the tires and axle gearing will be compounded by the time quicker at that speed than if the speed was only 20 on the same road surface.

I forgot to shift out of 4WD one day when I first got my Jeep, and as I approached 45 and went to shift, the front locker and the tcase got together and sent me across the road, and the steering wheel fed me some input that the drivetrain was not happy at all. My immediate selection of 2WD was smooth and effortless, but the gear driven D300 tcase works much differently than the chain driven NP231. I would not be surprised if the chain caused a loud clunk when it was released.