Unlock hubs in 94 Cherokee

These hubs don't "unlock". That's unless you've added aftermarket hubs. The backing up part is what you need to do if the shifter is stuck do to driving on a dry hard road and binding up the drive line. Earlier XJ's had a vacum operated unlock on the right axel but that was discontinued before yours was made (90 I think).

You have permanently locked hubs, the previous owner obviously had no clue how to use the 4x4.

You can shift on the fly into and out of 4 high at any legal speed on a Jeep. I just treat 4 H like any other shift and when I see a snow patch coming, I shift in, get back to dry and just shift back to 2x4.

When using 4 low for high torque and low speeds, you should be moving

2-3 mph only when shifting into or out of it or you will get bad noises. It clunks at the best of times going into low though.

Even with the older vacuum axled hubs, you didn't have to back up to unlock them. You sometimes have to let off on the gas pedal fast to bump the vacuum up to get them to work, but that is just because of old age and leaky vacuum hoses. If the shifter will physically shift to 2 wheel drive, you 'are' in 2 wheel drive period. The shifter disconnects the front driveshaft from the engine.

On my 86 CJ7 with locking hubs, I sometimes have issues getting it out of 4x4 low. The shifter itself won't move sometimes unless I spin rubber or goose it in reverse. This only happens after coming off a too high a traction area just before wanting to use 2x4 again.

So if the shifter won't move, you have to hit reverse sometimes or spin rubber, but the hubs don't care one way or the other.

Mike

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

snipped-for-privacy@gmail.com wrote:

Your point?

Do locking hubs magically prevent you from shifting out of 4x4 like the OP was told?

Mike

The Fuzz wrote:

Crap Bill, I can just see someone doing 65 mph and in order to shift having to stop on the highway and go backward against 70 mph traffic to shift to 2WD. LOL! Too funny....

Mike

"L.W.(ßill) Hughes III" wrote:

The hubs lock through a vacuum mechanism. There is a collar of sorts that slides over two splined shafts to connect them, this collar moves on command of a vacuum system. Sometimes the shafts and collar can bind, and going in reverse will release the bind and allow the collar to move back to its home position. This is not in the manual because it is not "required". It is helpful though. You can also release the binding, if present, by changing the load on the drive train, you can do this by letting off of the gas and turning the steering wheel from side to side.

If you shift out of 4WD, and can hear the resulting clunk from the movement of the collar, then you do not have to do anything else. In theory, all you need do is shift out of 4WD, and eventually the vacuum system will pull the collar back to its home position. In practice, the collar can stick and the remedy is to try going backwards for a few feet.

He doesn't have a locking front end, it is on all the time.

Even with the old vacuum lock, shifting is by a lever on the floor. If this lever on the floor will shift to 2 wheel drive, you are freaking 'IN' 2 wheel drive no matter if the front axle is a vacuum release, permanent locked, or manually locked!

There is no such thing as having to go into reverse to 'unlock' front hubs or axles period! That cannot happen on "ANY" Jeep!

Once the shifter has moved to 2 wheel drive, the front driveshaft is no longer connected to the drivetrain, therefore there can be no 'binding up'. The older vacuum collar cannot 'bind up' when the driveshaft is not connected....

Now if your gear shift won't come out of 4x4, then yes, you do have to maybe back up to shift the transfer case.

Mike

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

Jeff Strickland wrote:

Incorrect. You won't find the vacuum disconnect axle on a 1994 Cherokee. Last model year for that was 1991 for XJ/MJ and 1995 for YJ. The hubs on a 94 Cherokee are permanently connected straight through the axles to the differential.

Steve

Jeff Strickland wrote: >

Lucky you.....

We need it on the highway up here which is when the Jeep 'shift on the fly' system is so nice.

Mike

"L.W.(ßill) Hughes III" wrote:

But Mike, he was told to go in reverse to allow the mechanism to unlock. I was thinking he has the system like that in the YJ. It turns out he has the system that is like the TJ.

This is not entirely true. Well, it is true in theory. That is there is no requirement, but we all know that the YJ's front axle can balk at unlocking when the tcase lever is moved back to 2WD, the work-around for this balkiness is to back up a few yards.

I follow that, but what I have always seen is that the collar sticks. Backing up a little solves this. Having read about the lever binding up, my CJ has never had this trouble, so I assumed that any binding in a YJ would be the fork or the collar on the axle.

Just like the TJ?

I thought the Cherokee in '94 would have the same system as the YJ of the same year.

The confusion seems to be between the 4x4 and a vacuum slider or the dash light on the YJ's and early Cherokee. The light only means the axle hasn't released yet.

If the vehicle is in 2 wheel drive via the shifter and the slider doesn't want to unlock, you need to floor it up to say 3000 rpm, then let off the gas fast. This will boost the vacuum to the max and make the slider move and turn off the dash light. I guess you could also stop and back up to boost the vacuum because stopped is high vacuum but that isn't really practical if you are doing 65 mph or needed for that matter.

You can still safely drive at any speed or terrain with the front slider 'stuck' so the 4x4 light stays on but have the shifter in 2 wheel drive. On my 88 Cherokee that means about 3 mpg on the highway difference. My vacuum slider has been stuck 'on' for a while now and I haven't been physically able to crawl under to play with the hoses.

It is common for me to need to back up after coming out a trail before I can shift the transfer case out of 4 low in my CJ7. I have high traction so my Dana 300 can get pretty wound up sometimes. I then need to spin the tires. I still leave my hubs locked for half a year though.....

None of this has anything to do with the front axle or hub locks though, they are a totally different animal and are completely different than the 4x4 shift.

Mike

Jeff Strickland wrote:

Yup, they ditched the problematic disconnect in '92 in the XJ coil link suspensions. They didn't bother investing the same change for the YJ's leaf-sprung Dana 30 knowing it was a dead duck soon to be replaced by the XJ coil link Dana 30 in the TJ.

Steve

That still has absolutely 'nothing' to do with unlocking the front hubs!!!!

That is the t-case binding up. It happens on my dana set up too because of the high traction muds I run.

I thought the real bad set was the 410/411 splits on some of them.

Mike

"L.W.(ßill) Hughes III" wrote:

The best work around it to hit 3000 rpm and let off the gas for maximum vacuum.

Going in reverse has 0 effect except at the idle point when the vacuum comes up because the transfer case is already in 2 wheel drive so the driveshaft is loose already.

Mike