Hot Hub /Wheel - Help diagnose Please

[Sav'h Steve]

Was leaving on trip this morning. When we were 30 min from home I checked tires/wheel with infrared gun. (25ft Excella double axle.)

One wheel was hot. The other 3 were 96 to 120. But the 4th was 200 deg F. Double checked several times and it felt hot to hand.

Thought I had a dry bearing, so came home and repacked bearings. Outer one was a little dry, but both looked great after cleaning. Brake shoe looked normal - there was a slight drag, so backed off the adjuster.

Went ahead and did the other wheels and all looked OK. Now I know they are good and packed with grease (did the bearing in the palm thing).

Got my wife and took it for a test spin for 20 min or so. Same wheel was
STILL HOT!!.

It could be a dragging shoe on the edge. Don't know how to fix that or just let it wear some. The brake shoes were all replaced a year ago. I didn't think to check the brake springs when I had it apart - nothing looked broken when I looked.

May have to take it off again. Ugggh ..... Any thoughts??
Steve

[Jammer]

Take it out and carefully drive without applying trailer brakes then see if the temperature is still hot. You may have one brake doing all the work.

Also if you check immediately after stopping you might be able to tell with the IR thermometer whether the hub is hotter than the outside of the drum or vice versa which should be a clue.

[Sphere Guy]

Sav'h Steve,

Where are you measuring the temp. Tread temp? or hub temp? My TPMS routinly only goes up 5 to 6 deg after 1 hr towing on a tandem axle 23ft.

200 is high for a hub temp but reasonable for tread temp. What was the relative temp of the area you were towing?

[Sav'h Steve]

This was hub and wheel temp only not tire temp. I only used the breaks lightly coming to a stop...I did notice a slight put to that side when coming to a stop.
Thanks for your help
Steve

[garry]

Low air pressure increases air temp dramatically verify good air pressure.

Also pull for a short distance with the trailer disconnected from the TV to verify the magnet in that wheel is not shorted OR disconnect that wheels electrical connection if you don't want to pull disconnected.

[dznf0g]

As Jammer mentioned, I would check for that brake doing most of the work. I sounds like you ar knowledgeable on brake adjustment and bearing repack and adjustment, so I will confine my theory to electrical. If you have high resistance (in this case) to 3 wheel magnets and a good power supply and ground circuit to the fourth, that fourth wheel is going to be doing most of the work, and thus most of the heat build up will be there. Check all of your power supply wiring and ground path connections for corrosion causing high resistance. Also check the voltage supply wiring for any areas of chafing of the insulation which could cause a short or no voltage to wheel magnet(s). I am not sure if AS ever ran their wiring inside the axle tubing or not, but if they did on yours, pull it out and run it on the outside of the tubing with proper attachments. Wires in the axles are notorious for chafing through and causing brake issues.

[Sav'h Steve]

Thanks guys!! All the tires were fine and at near same psi. Just checked before leaving.

dznf0g: I did back off that brake adjuster some the first time, so I doubt it was taking all the work. Matter of fact I had the brake controller turned up all the way since none were locking up when controller only applied... does the wheel itself need to be installed for the magnet to work ie with the drum off the wheel?

I did re-pull that wheel and inspect the springs. They were fine. I slacked off the brake all the way to where it does not stop the 'up in the air' wheel when brakes applied.

Tomorrow I will pull and recheck temps before leaving town. Think I'll disconnect the brakes from trailer (unplug 7-way) and try that also. Truck will stop it, but won't go on trip without trailer brakes - at least on 3 wheels.


If high, I'll stop by a wheel center well known in town and have them look at it.

Talked to a neighbor who has lots of experience and he said I'd done all he could think of.....

Suggestions??

TIA Steve

[dznf0g]

"dznf0g: I did back off that brake adjuster some the first time, so I doubt it was taking all the work. Matter of fact I had the brake controller turned up all the way since none were locking up when controller only applied... does the wheel itself need to be installed for the magnet to work ie with the drum off the wheel?"

This bothers me, I'm not sure what you are saying. The controller should be capable of locking up all the wheels. The drum does need to be turning in order for the magnet drag force to pull the shoes out against the drum.

If you have an electrical issue severe enough in the three wheels, just backing of the one a little will still allow it only to apply. With your experiment with the one good one backed all the way off so as not to apply at all, you may find you have virtually no brakes whether the 7-way is unplugged or not.

[Sav'h Steve]

Thanks for coming back!

I have them backed off to diagnose the problem. I do have some trailer braking effect - but not locking any wheels presently.

I did buy "Never Adjust Brakes" which are supposed to adjust when backing and braking (I think). I can rotate the adjuster tighter thru the backing plate later w/o taking off the wheel - haven't done it yet.

Not sure why you say it bothers you. It concerns ME that you said that. I don't want to do something stupid. BTW I am not a mechanic, just don't like the near $100/hour labor rate!!!

[dznf0g]

It only bothered me 'cause I'm not sure what you were saying. I thought you were saying the brakes wouldn't lock up with them adjusted properly. After your "unplugged" experiment, you can adjust them up, take the trailer to a gravel lot or deserted road, turn down the controller all the way. Drive about 5mph and fully apply the controller manually, just briefly and sharply. Keep turning it up one step at a time. When you start to get wheel(s) sliding, get out and check which one(s), as evidenced by marks in the gravel. If they are all sliding at the same setting and relatively low on the available adjustment scale, your wiring, etc is probably OK and you should pursue the bearing avenue. If they start locking up at different settings WITH mechanical adjustment done properly, I'd look for wiring issues.

I'm just leaning so heavily on this route because you had the bearings in your hands. If they were causing a significant heat rise, I'd think you would at least see brown deposits on the rollers and/or bluing of the rollers and maybe races. Or etching....etc.

[Wsmith]

If you have all brakes working you should have a amp reading of about 12maybe 14 this depends some on voltage drop to the trailer. If it is down to 9 then you would have one brake magnet not working. If you end up with a much higher reading then there is probably a direct short somewhere. Some of the new controllers give you this information on the display. So if you get a 3-4 amp reading you would have three wheels not activating.

[Sav'h Steve]

Originally Posted by dznf0g

It only bothered me 'cause I'm not sure what you were saying. I thought you were saying the brakes wouldn't lock up with them adjusted properly. After your "unplugged" experiment, you can adjust them up, take the trailer to a gravel lot or deserted road, turn down the controller all the way. Drive about 5mph and fully apply the controller manually, just briefly and sharply. Keep turning it up one step at a time. When you start to get wheel(s) sliding, get out and check which one(s), as evidenced by marks in the gravel. If they are all sliding at the same setting and relatively low on the available adjustment scale, your wiring, etc is probably OK and you should pursue the bearing avenue. If they start locking up at different settings WITH mechanical adjustment done properly, I'd look for wiring issues.

I'm just leaning so heavily on this route because you had the bearings in your hands. If they were causing a significant heat rise, I'd think you would at least see brown deposits on the rollers and/or bluing of the rollers and maybe races. Or etching....etc.

Actually, this is the best definition on how to adjust each brake that I have seen! Thanks for your post!! I would not have considered turning the controller (Prodigy) all the way down to do the setting. Seems you want some lessor braking control and would put it someway in the middle... just saying. I'm printing this one out!

The rollers were not discolored at all, and the races were clean. Steve

[Sav'h Steve]

Originally Posted by Wsmith

If you have all brakes working you should have a amp reading of about 12maybe 14 this depends some on voltage drop to the trailer. If it is down to 9 then you would have one brake magnet not working. If you end up with a much higher reading then there is probably a direct short somewhere. Some of the new controllers give you this information on the display. So if you get a 3-4 amp reading you would have three wheels not activating.

This is ALSO very good info. I'll have to note the amps applied. Don't remember....

[dznf0g]

Originally Posted by Sav'h Steve

Actually, this is the best definition on how to adjust each brake that I have seen! Thanks for your post!! I would not have considered turning the controller (Prodigy) all the way down to do the setting. Seems you want some lessor braking control and would put it someway in the middle... just saying. I'm printing this one out!

The rollers were not discolored at all, and the races were clean. Steve

To clarify, your final setting after all is good and done, is to have the trailer wheels just at the lock up point on dry hard surface with a hard TV apply. The manual lever should be able to easily lock up all wheels on dry hard pavement. Where on the controller scale that falls, I think will vary by controller manufacturer.

[Sav'h Steve]

Originally Posted by dznf0g

To clarify, your final setting after all is good and done, is to have the trailer wheels just at the lock up point on dry hard surface with a hard TV apply. The manual lever should be able to easily lock up all wheels on dry hard pavement. Where on the controller scale that falls, I think will vary by controller manufacturer.

This is interesting. Since my TV is a F250 and (thankfully) easily controls the Stream, I would not have set it that high for fear of the trailer dragging the truck to a stop. Not to mention slight lockups on turns, etc. Maybe need to rethink my settings ideas......

Much to learn from all you pros on this site. (And I thought I was a semi-pro LOL).

Steve

[dznf0g]

Ideally, the trailer brakes pretty much take care of the trailer weight and the truck brakes take care of the truck and bed load. That would be a balanced setup least likely to get you into a jack knife on wet surfaces particularly. Some folks even like the trailer set a little harder so there is always "tension" between the truck and trailer upon brake apply. I personally prefer a neutral balanced feel....maybe a slight amount of tension.

[TG Twinkie]

Try backing the spindle nut off a couple of flats. If the hub is getting hot, it may be that there is too much preload on that set of bearings.

[63air]

I would pull the seal and clean/inspect the bearing . If it shows any sign of overheating I'd replace it.

[BAB BMRZ]

Great thread. I've learned a lot.

Tnx Lyle

[dznf0g]

Originally Posted by 63air

I would pull the seal and clean/inspect the bearing . If it shows any sign of overheating I'd replace it.

He already did that. Says all OK.