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Hey ya'll.. I am have been at this for over a year and I think its time to drop it on here. In that year, I have taken my J10 to many mechanics and off-road shops. Without prevail - stumped.

Ever since I bought the truck, my hubs and lug nuts are screaming hot. Over 400F degrees. no way I could touch. Rotors get blue, you know what i am saying. So let the labyrinth begin. I figured since the J10 was sitting on a farm field for 2 years and burred in the earth - i would have to change some things Thought this would be a fun project with my 13 year old, teach him some things and when he turns 15 - this year- he will be able to get himself a Jeep and start the process over. Thus far, its bee amazing but this one issue.

For full transparency, we have replaced:

• Hydroboost system from Elliot ( he is on here - AWESOME DUDE!)
  New MC
  New PS Pump and Box
  New Manual Locking hubs ( with bearings, race, lock nuts, grease,etc)
  New lug nuts and lug pins
  Steering shaft with Ujoint system (Borgeson)
  New Water pump
  New Steering linkages
  New Ball Joints and U joints
  Knuckles sand blasted and re painted
  2x New Prop Valve (Tuff Stuff)
  2x New Calipers
  New Rotors
  New Brakes
  New Stainless Steel Brake lines
  All new Brake rubber hose to caliper
  New Drum Brakes
  New Headers
  New Suspension - Skyjacker
  New 600 Holley carb
  New..
  New...
  New....

You get the point.

With all of that changed, our hubs and lug nuts are 400 degrees. As you can see we have "2x" by the calipers and prop valve. My calipers were getting hot (110F is that hot?) and I could not move the caliper. Slider pins were stuck. I greased them and figured that was the simple fix. NOPE.

Moved to the prop valve. I had a CCP valve and didn't realize those were made in China. I did some research an many blow through them and thought that I have found the problem! Naturally, my bias was off and fronts were getting all the pressure. This could have been done from the initial bleed. I have then invested in a prop bleeder tool. PS - all mechanics never heard of this tool.

As much as it has fixed a lot of the heat, as it is, it still is causing some heat. The good news after replacing with a TUFF STUFF prop - my new temps are 135F at the nuts, rotor and hub. Caliper is 100F. Still hot in my opinion but ya'll tell me. No spit sizzle and can manage 2-3 secs holding onto the lug nuts. It seems the lug nuts are the hottest in every attempt to fix.

I have heard so much from mechanics:
- need to convert to all calipers b/c all calipers are reman
-Hydroboost is too much for that Jeep
-axles are old (they have never pulled them out so not sure what they are saying here)
-Warn hubs are the wrong ones. (not according to WARN when ordered and confirmed)

The only thing I have not done is change out the front diff oil. Could dirty or lack of oil create that friction when the wheels are turning? We have the front shaft disconnected b/c we replaced the welded gears in rear to 4.10. Therefore when I get more money, I can finish the fronts.


Any help would be great. Anything i have not thought about? Not sure if its me or the J10 being stubborn but I need help as I am tired of this one issue.

Wow, quite the adventure.

Typically, only two things could cause what you are seeing.

1: The bearings are over tight. But they would have to be really over tight for what you are seeing.
2: The brakes are dragging. Sounds like the proportioning valve was maybe your cause?
Note: Low diff fluid would heat up the center section, not the hubs

Our of curiosity, if you are rolling down the HWY at say 50, and you shift into neutral, does the truck slow down a lot faster than it should? After the fix, it should coast along pretty good.

100F on the calipers seems totally normal to me. But it kind of depends on how far you drove I suppose. Brakes can easily hit 300-400 degrees when towing.

135 is pretty hot for the hubs, not out of sorts if its 90+ out side but if its 50 yes its too hot but not extreme. My guess is wheel bearings are too tight, seen it often. repack the bearings with quality wheel bearing grease and follow the factory procedure for tightening them, and like the proportioning valve tool that mechanics have never seen or heard of they often do not know the proper tightening sequence for wheel bearings. I've seen them tighten them up like they are putting an axle nut on a unit bearing that gets torqued to 250ftlbs and then complain about warrantee on them

Have you removed and cleaned the hubs and repacked the hub bearings? If so, is any of that stuff blue steel?

Stuka wrote: ↑Sun May 02, 2021 9:24 pm Wow, quite the adventure.

Typically, only two things could cause what you are seeing.

1: The bearings are over tight. But they would have to be really over tight for what you are seeing.
2: The brakes are dragging. Sounds like the proportioning valve was maybe your cause?
Note: Low diff fluid would heat up the center section, not the hubs

Our of curiosity, if you are rolling down the HWY at say 50, and you shift into neutral, does the truck slow down a lot faster than it should? After the fix, it should coast along pretty good.

100F on the calipers seems totally normal to me. But it kind of depends on how far you drove I suppose. Brakes can easily hit 300-400 degrees when towing.

Stuka - totally the adventure. I just want to drive it, but having a ton of fun building this awesome Jeep

I would have to say that the bearings always could be overtighten. I am human and make mistakes. I had them double checked by an off-road shop and they rechecked to make sure they were ok. - still the issue. it would be nuts if we both messed that up.

Regarding the brakes dragging. the prop valve was def the problem. when changing it, it took it from over 400F to just over 100F.

I have not tried the N at 50 yet. Its an automatic so I would have to be careful. Weather was mid 70's to 80's. steep hills with many stop signs.

Yeller wrote: ↑Wed May 05, 2021 5:31 am 135 is pretty hot for the hubs, not out of sorts if its 90+ out side but if its 50 yes its too hot but not extreme. My guess is wheel bearings are too tight, seen it often. repack the bearings with quality wheel bearing grease and follow the factory procedure for tightening them, and like the proportioning valve tool that mechanics have never seen or heard of they often do not know the proper tightening sequence for wheel bearings. I've seen them tighten them up like they are putting an axle nut on a unit bearing that gets torqued to 250ftlbs and then complain about warrantee on them

I do not doubt it! thanks for the reply. i might have to dive into those hubs again if i can not figure it out. Temp was close to 80's, high humidity.

fulsizjeep wrote: ↑Wed May 05, 2021 6:17 am Have you removed and cleaned the hubs and repacked the hub bearings? If so, is any of that stuff blue steel?

Thanks for the reply! when i changed out all the parts within the hub, i packed them good. blue steel? I do not think so but I'll have to check. i used Timken parts and within the steering linkage are MOOG.

what are you thinking?

So far, I'm thinking the hub bearings are too tight.

Man - that would something. Within 100 miles they were touched and torque down at spec twice. Then new prop valve was installed and we saw a huge decline in temp. That is my only hesitation.


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I am at a loss. Maybe brake pad(s) dragging on the rotor (even intermittently) which could point to a caliper issue.

Doesn't seem that hot to me but whatta I know? Both sides the same? I assume you've jacked up the wheels and see how they feel?

Got a path to get to the highway without touching the brakes or just using the parking brake? Maybe late or early morning so you can drive it a while and see if anything gets hot? Could exonerate the bearings and dragging brakes.

Thanks guys.

So took for drive and same story. Calipers were slightly 70 degrees. Everything else the same. Highest mph was 55

Great point on brake pads. Before the prop valve I was getting crazy dust which what hinted to me on brake bias. No brake dust since valve change.

I do have those original wheels on there. Not sure if that info that is helpful.


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SJTD wrote:Doesn't seem that hot to me but whatta I know? Both sides the same? I assume you've jacked up the wheels and see how they feel?

Got a path to get to the highway without touching the brakes or just using the parking brake? Maybe late or early morning so you can drive it a while and see if anything gets hot? Could exonerate the bearings and dragging brakes.

Correct. Wheels jacked up - all good. Both are same temp.


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**UPDATE** took it out for a spin today.. same drive 10 miles-15 miles. Smoke from the right caliper slider pin area. 250+ degrees. if you put your hand just below 12oclock, you can feel the heat. foul smell as well. i am guessing caliper is sticky.. now the why.. just put these on when i started this thread and third time driving since this thread. Guys i am getting desperate.

both sides are the same temp and results. i di not see smoke on drivers but same smell.

Seems to me like the master or prop valve is holding pressure in the line. I don't see both calipers being moused up unles you have incorrect parts in them. How hard is it to push the piston in?

Thanks for reply bud...Pistons are not hard to push in. 1x and c clamp - very little resistance.


During drive I stopped for 1hr. Took off after that, it was awesome. 5 miles in same result. My pedal went really hard once I got home.


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Hydro boost valve leaking pressure to the front brakes. Lift the front wheels off the ground and run the motor[not in gear]-dont touch the brakes. Accelerate, idle etc all while checking the front tires to see if the brakes start dragging. If the brake arent dragging, activate the brakes several times over a 5-10 minute period and see if that causes the brakes to drag. It has to be that the pressure is building up or not releasing.

I think your right on the pressure. That makes total sense - although I am not confident that this the same issue from original post but a new one.

Prior it was always dragging (from engine start) then gets super hot - now it drags after 3 miles - gets super hot then smoked(1st time ever). I looked at the prop valve and the brake indicator looks defective. I wonder if that was blocking pressure? This would be a solution to the latter issue.

I’ll have to play with it this weekend. Thanks!


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SJTD wrote:Seems to me like the master or prop valve is holding pressure in the line. I don't see both calipers being moused up unles you have incorrect parts in them. How hard is it to push the piston in?

I think you were into something - I think the brake indicator in the prop valve was faulty and created the pressure. Have a new indicator and testing probably today.


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I'm not familiar with how HB works, Rock is.

I'd look into his suggestion.