Slipping in 4x4 low

A u-joint going bad will cause symptoms like that.

So can a bad engine or tranny mount.

If your driveshafts have slip joints in them, a lack of grease there can also cause it.

A control arm bushing gone bad also.

A few ideas for you.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: N>

Yes, it's on dry pavement. I first noticed what felt like binding in the rear, as I was stuck in a very long traffic jam (45 minutes of inching forward around a bend, up on a curved roadway), that would disappear as I shifted out of low (1-2 Automatic Transmission), into neutral. It went away as the road flattened out, but we decided to check all the gears, and that's when this was noticed. I never noticed it on the last 98 Cherokee Sport I had.

Thanks for your help.

Sheila Vancouver BC

Read the back of your sunvisor on the driver side.

Ouch, forget what I posted about what to look for....

That was your driveshaft or drivetrain winding up like a clock spring trying it's best to detonate the transfer case into many many little pieces....

You cannot run part time 4x4 on pavement. The front and rear axles get locked together and they spin at different rates when the steering wheel turns or even just going straight on some. This means one tire 'must' scuff on the road or you 'will' explode something.

I just blew a front driveshaft u-joint doing that last weekend. I was on a trip running snow at 60 mph and came to dry road. By the time I realized it wasn't going to snow anymore I couldn't get it out of 4x4 high it was so wound up. I had to get off the highway and stop, then spin my tires to unlock things. The damage was done though, it took out one bearing cap on the front u-joint. Grr... At least it only started going BANG BANG BANG about 5 miles from home....

Our old tenant blew his transfer case to pieces doing the same a while back. Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Aug./05 (More Off Road album links at bottom of the view page)

The reason Jerry asked about pavement is because if you have Jeep's Command Trac 4-wheel drive system, it is strictly a part-time system that should NEVER be used on dry pavement. The Command Trac system mechanically locks the front and rear axels together. Since the front and rear axels turn at different speeds, this system must only be used on slippery surfaces, like snow, ice, mud, dirt, etc. If used on dry (or even wet) pavement, the drivetrain will bind up and cause damage to u-joints, transfer case, etc. You will actually feel the tires skidding and hear chirping, especially during turns.

If you have Jeep's Select-Trac system, it has a full-time mode which can be used on any surface, even dry pavement. It also has a part-time mode which acts just like Command Trac.

If your transfer case selector lever has a full-time position, you have Select-Trac.

Tom

I think Jerry was asking if it was making the noise while on pavement in

4WD. You shouldn't use 4WD on pavement unless you have Selec-Trac. If you have Command-Trac, use only on slippery or loose surfaces.

-Brian

Sheila, that's the problem... the kind of 4x4 system in your Jeep, whether it's in 4Hi or 4Lo, is not supposed to be engaged when you're driving on pavement. Your 4x4 system mechanically locks the front and rear axles together so they are forced to rotate at the exact same RPMs which won't work, since the front tires rotate faster than the rear tires in normal driving conditions. Turning, driving on mild curves, even just straight-ahead driving will bind up the drivetrain as the front tires try to rotate faster than the rear tires.

Avoid using 4wd on pavement and it'll be fine, your particular 4x4 system is designed for offroad use only... or when the paved streets are 'totally' covered in snow or ice.

There are some 4x4 systems that are designed to be used on paved streets, and it was optionally available on Cherokees like yours, but those have an additional 4x4 mode called 4Full (full-time 4wd) which is designed for street use. Unless your Cherokee has that mode available, stay in 2wd when you're on a paved street. :)

Jerry

snipped-for-privacy@hotmail.com wrote:

Oops... guess that really wasn't such a good test then huh? I normally only do run the 4x4 in snow or off road - my bad :-). Thought since this Jeep was new to me, we should check and see if the original binding sensation would repeat itself in 4x4 mode....then discovered the slipping and was concerned.

Any clues as to the originally binding noise/feeling during the drive on the curved road surface?

Thanks for everyone's input - very helpful guys!

Sheila Vancouver BC

If the rear axle has a slip joint, maybe it needs grease.

Wouldn't hurt to put it in neutral, block the wheels and check the u-joints out. They make a clunk though.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >

Yikes. Part Time 4x4 , Hi or Low, is not for use on dry pavement. What you are feeling is the transfer case binding. Stop before you break something.

However Selec Trac doesn't have a full time 4x4 Low position IIRC.

Sometimes if you shift out of 4x4 part time into 2wd the T case won't disengage immediately...the torque load will hold it engaged. Driving a curved road will give you those binding sensations.

Shifting the transmission into N or letting up on the gas after you shift the Tcase will help the Tcase to snick back into 2wd.

Mike explain the pictures to her.

hmmm... except the only time that I actually switched (using the 4wd shifter on the floor,directly beside the 2wd shifter) to 4wd, was 'after' I experienced the binding while trying to save my brakes/foot and using the low gear (bottom setting on the 2wd shifter) to coast slowly. If I shifted back to neutral, the feeling/noise went away immediately.... once the road was flat again, everything seemed to be back to normal again, and I continued driving in my normal "Drive" gear in 2wd. I suppose I shouldn't be shifting to low gear like that either huh? Man, and I 'thought' I knew how to drive! lol

Sheila Vancouver BC

Correct.

-Brian

I drove mine in four wheel high on dry pavement for five or ten miles once, and nothing happened. I think the reason is that I didn't KNOW that I was in four wheel high. Or maybe since I was on a twisty mountain road all the turning to and fro kept the drive train unloaded. Or maybe the puny four cylinder engine is incapable of grenading the drive train. I did notice some loss in power, and had a dickens of a time figuring out what it was. I'll bet you all have done this...

Earle