How freely should a front tire spin when on a jack?

Not sure how much resistance there should be. I know the disk brake and front axle & drive train will add a little, however how much? In other words, how freely should a tire spin when on a jack??

I want to make sure everything is adjusted properly before a long highway trip to Colorado. I drive a 2001 auto/242 with an open front diff. Right now there seems to be substantial resistance when I spin a tire with one side resting on a jack. Both sides have the same amout of resistance too. Hubs are quite warm but not hot when driving on the highway. Not sure if there is a problem or not.

Many thanks for any info provided.

If you are exactly as strong as me, there is something wrong if you have to use all of your might.

should be easy, atleast it is with mine and 33s.

Sounds like hubs/bearings?

Yeah, that's what I thought too however from the searching I have done, it seems that hubs are suppose to be warm if not quite warm when on the highway. Yes/No? If so how warm??

the hubs will be warm from the heat transfer from the disc brakes.

if the hubs are bad they will make the wheel wobble a bit and/or make a grinding noise.


if the hubs where not spinning freely/seized and taken on a highway trip, they would be red hot.

There will be some resistance as the brake pad does have some drag on the disc. How many rotations does it make with a good shove?

The wheels (both) only spin about a .3 turn after a good shove. I am taking to the shop (Jeep Masters in Austin) next week. Because the problem is with both front wheels, I want to eliminate a potentially bad proportioning valve or master cylinder.

Many thanks for the reponses. I will report what is found for the group.

If, for some reason, there is excessive pressure being help on the brakes it could also be a bad hose.

Spinning about 1/3 of a turn is what I would expect from a wheel that is connected to a differential and driveshaft. And both wheels are the same. You could jack up the front end and tap the calipers back and forth sideways to take any residual drag off and try spinning them again. That should make it just a little easier to spin.

Update – I took off and inspected the front brake calipers and all appears to be OK. Wheel bearing seem fine, no play and smooth. Calipers slide off the disk and everything is moving on the caliper assembly how/where it should. The brake pads are pretty new so maybe the brakes are still settling in? I then drove at highway speeds for 15 minutes without applying the brakes (coasting to a stop) and touched the disks and drums. This is what I learned: both front disks equally very very warm. Both rear drums mildly warm. The day was about 80F. So the resistance when a front tire is spun when on a jack appears to be quite substantial - about 1/3 rotation with good shove. Evidently the combination of normal “light” disk brake drag along with the paired D30/NP242 front axle configuration provides a surprisingly significant amount of resistance from my observation.

2001 XJ limited w/upcountry
ARB bumper w/Warn winch
OME lift & shocks w/ACOS pros
235/70/16 Mud-Terrain T/A® KM2

Is it steady resistance or does it spin free 1/3-1/4 of a turn then bind? Is it harder to spin with the steering wheel turned? You may have bad U-joints, at the axels or on the driveshaft.

Youy don't have it in 4x4 while doing this check do you? Make sure you have in 2wd (all the way forward).

Nick

The resistance is consistent with both wheels full revolution – that’s what amazes me. Both front U-joints and wheel bearings are fine. And not in “full time” 4wd from what I can tell.

I guess the resistance is one of the reasons 4x4 XJ’s get such poor mileage? I have done my best to troubleshoot any brake problem but all seems *normal* I Guess.

Do XJ’s with a vacuum front axle disconnect have front tires that spin more freely??

Less spinning parts, less resistance. Not only does all that stuff have to spin, but it also weighs a lot, decreading mileage even more. The more you disconnect, the easier it will spin. That's why unlocking/locking hubs are a benefit. Unfortunately, they cost so damn much to put on an XJ. I have no doubt at all that yours is normal. About the only thing you can do for a little improvement is to use synthetic dif oil.