Help! with one wheel heating

[DaKarch]

2004 Safari Passenger front axle (dual axle AS) wheel heating up.....Driving me crazy. Lots of details below....

July:

Passenger front axle wheel set TPMS alarm at 190F. Magnet fried, shoes de-laminated.
Road side fix...Put new AP Products assembly on purchased at Camping World

Drove NC to FLA then Home to PA...TPMS temp on that wheel always ran say 10-15 degree hotter maybe 126F tops.

Present:

Several small trips in the hills of PA. Wheel stared heating to 150's noticing smell.

Whats been done:

I am leaving out some details as this has been a long process.... 4 New matched magnets 7k ( new assembly had 7k Magnet and originals were 6K). New brake shoes rear axle. 4 new bearing seals. 4 Bearings cleaned and repacked. Brakes adjusted several times (full out to lock then back off 8 clicks)....even adjusted the hot wheel out another 10 clicks

Electrical testing:

12v at TV plug
1.2 Ohms for both axles (measured at AS plug blue and white pole)
13.7 Amps measured at trailer blue wire from gang box
average 3.4 amps at each magnet
Average 11.4 Volts at each magnet
Tighten ground wires at ground junction in trailer

Hot Wheel testing:
With trailer plug disconnected, continuity to ground on both lines to magnet
With trailer plug connected, 11.4 volts to ground
With trailer plug connected, continuity from metal of magnet to ground but no volts
Nothing binding, springs return
No grease on shoes from bad seal

Just got done with test drive after magnet replacements. With minimal braking mostly highway...hot wheel rose to 132F while other 3 wheels ran around 104F. Easy braking off highway to home hot wheel went to 179 on TPMS.....

Hot wheel spun free at that high temp..no harsh dragging sound either (tested with tire off of the ground). No wobble or play on bearing at low or high temp.
Pulled the hot wheel while hot (ouchy)....with thermal couple drum temp near spindle was about 218 and at the outer diameter 224F


Thinking about replacing hub and drum (may switch it to other wheel and see if other wheel heats up first) Unless someone can say, yep do it this happened to me and it was the drum/bearing.

I think the electrical debugging eliminates a bad ground or bad brake controller. But my experience tells me bad grounds can be tricky. I am thinking it is electrical and that is why the other brake assembly failed.

Could be bad brake material on that new assembly.

Thinking about rebuilding old backing plate

I am at a loss...At the forums mercy...

[the ponz]

Consider disconnecting the the electrical connection to the magnet on the hot wheel, then drive a short one to two hour run and see what the temps indicate. I would think that by disconnecting the magnet, the problem could be better isolated.

[PaulnGina]

The bearing hasn't been replaced?

[DaKarch]

The bearing has not been replaced. Races look good and no heat marks. As well as no play radially or axially.

I would have thought if the heat was coming from the bearing that the drum temperature would have been hotter near the center than at the outer diameter.

[switz]

Wonder if it was a dragging brake shoe from a weak spring?

[DaKarch]

New backing plate = New springs. Solid return when manually manipulating the actuating arm.

Also spins freely at the high temperature. no dragging and no binding

[PaulnGina]

You know what??? As easy as those assemblies are to remove and install (once the trailer is supported), I think I would swap the entire brake/backing plate assembly with the other wheel, then see where the heat is.

Might try disconnecting the magnet first, though, as was suggested. Probably the easiest way to isolate.

[richinny]

are the backing plate assemblies on their respective (left/right) sides?

[DaKarch]

Correct backing plates on all 4 wheels.

[r carl]

Originally Posted by the ponz

Consider disconnecting the the electrical connection to the magnet on the hot wheel, then drive a short one to two hour run and see what the temps indicate. I would think that by disconnecting the magnet, the problem could be better isolated.

Yes, that is the first thing to do now. Process of elimination.

[Bill M.]

"No wobble or play on bearing at low or high temp."

There should be just a little play in the wheel when the bearing is set right. A too tight bearing can heat.

My guess is a dragging brake shoe for some reason.

[DaKarch]

Setting taper bearings is simple....after repacking, put a little pre load on...spin wheel. loosen, repeat....final set - Turn snug, back off one notch in castle nut. Same process for all wheels, no excess heat in the other 3.

[DaKarch]

By the way...I appreciate everyone's replies!

[Al and Missy]

I presume your voltage readings are with brake pedal depressed. What are they without the pedal depressed?

Al

[Jacob D]

From industrial maintenance experience, too much grease and no place to expand can heat bearings. The other suggestions made to isolate the problem are things we would do to trouble shoot similar probs in machinery.

[tjdonahoe]

You say no play in bearing? I always set my bearing tight while turning wheel then back off , then tighten with my fingers, when run a couple miles you will have a couple thousands play , just right , did the big trucks and trailers this way and never any problems.

[SSquared]

I've never seen this happen, but could it be a bad tire? Maybe you had some random thing cause the brakes to drag the first time, this might have damaged the tire from the heat....so now the tire squirms and generates excess heat by itself....?

If you swap your backing plates to isolate the problem, try swapping the tire to a different position at the same time.

[DaKarch]

Well its not electrical....disconnected wires to hot wheel. Tire went to 150 in 20 miles. Other tires at 110 with brakes working and I was in stop and go traffic for half of that drive.

So I am betting on the TPMS showing me a bearing about to fail. Changing bearings and drum simply because I can get the assembly for $80 locally.

Will know soon....

If too much grease the heat would have most likely pushed it past the seals....

If the tire was it the drum would not have measured 225F and the tire 180F

[bwoodtx]

Make sure that the bearings, inner and outer will slide freely on the spindle to their shoulder stops. Do this without them installed in the hub.

I had one doing this and found my outer bearing sticking on the spindle. Took it off, polished spindle with emery cloth, LIGHT coat of grease, reinstalled, set load-no more issues. I have found that not all wheels will run same temp, but should be fairly close.

I think it is a bearing issue. You could also run it w/o the backing plate on and that way get a accurate temp reading on inner and outer bearing, narrowing it even further. Extra work, I know, but beats losing a spindle and have to buy a new axle.

Hope you find it.

[DaKarch]

Welll...its not the old hub and bearings. Put new dexter stamped hub, packed with red grease new bearings and races, new seal.....

145F only difference is that the same trip last night had me running at 180F....but I set the gain real low as to not lock up that wheel.

Tomorrow I will swap the right side brakes...it will either follow the new backing plate or somehow be the spindle...or some overlooked electrical issue....

Someone asked if there was volts when brakes not engaged.....1st I was using the controller to apply the brakes not the pedal and second volts with controler not applied are 0V