Deuce Rear Hub Runs Hot

[cleb]

Hot Hub

Hello all,

I got my M35A2 at Ft. Lewis about a year ago. One the way back the most rear hub on the drivers side ran hot. I got the truck home, and after a month or 2, it started leaking gear oil into the brakes, and pushed the grease out. I took both sides on that axle apart, re-packed, and put new seals in. The passenger side hub ran fine, but the drivers side still ran hot. I tightened both to the same spec, and they both felt the same, no play, but not too tight as to bind up. I replaced the seals, bearings, and race on the hot hub. It still ran a lot hotter than the rest, but I drove it 360 miles to school anyways. After a few months of driving here, gear oil coming out again. I replaced the bearings, races, and seals again, and used the black molly grease from napa a mechanic recommended (instead of the yellow stuff). Got it all back together, and torqued right, felt good, and its still running hot. It seems like its only the outer bearing. The end of the hub is hot, but the closer you get to the lug nuts and inner bearing, it gets cooler. The end of the hub after a run at 50 for 8 miles is too hot to touch for more than 1-2 seconds. I think it cooked the seal last time, and let oil in, cooked the bearings. Any ideas? Someone said it might be a bent axle, so I'm going to try pulling that, and taping a bag over the end. Could it be the hub? We seated the races all the way in where they should be, checked with a mirror. Bent spindle? A bit fustrated at this point....

Thanks,

cleb

 

[halftrack]

Are hubs suppost to be slightly warm after long running. Mine are. Or are they to be cool to the touch all the time. Just to add to the above post.

 

[FMJ]

Are hubs suppost to be slightly warm after long running. Mine are. Or are they to be cool to the touch all the time. Just to add to the above post.

I check mine regularly with an IR therm, and mine run right around 120-130 Degrees.

Possible for it to be a bent axle, swap it to another location and monitor that hub.

 

[cleb]

Update: I pulled the axle and drove around without it. Still extremely hot on the outer axle. Melted the plastic bag that I had on to keep the water out and oil in. Mechanic here thinks its a bent spindle, going to check with a dial indicator later and see if its out of whack. I kinda doubt its the hub. Anyone have a scrap rockwell that they could torch a spindle off of? Mechanic said a machine shop here in town can remove the bend one and re-weld.

 

[gringeltaube]

Hot hub

It seems to me that some of the aftermarket (chin-chu-lin brand???) seals fit way to tight against the outer cup. That excessive friction causes heat! Result: very quickly that seal ends up fried and leaking oil like the old & worn part that was replaced!

Pack the bearings with regular grease and adjust as usual but without the outer seal installed (Just in case: outer = the one that goes between bearing and nut). Try a short test run (don’t worry, nothing will fall apart!) and feel the hub. If it’s OK now I’ll show you what I do with that seal.

G.

 

[Nonotagain]

Do you have access to a set of inside and outside micrometers?

If the axle is pulled and the hub still runs HOT, it can't be the axle.

Try swapping the hubs from left to right side and see if the hub assembly still runs hot. If the same side still runs hot, then I would look at the axle housing being bent. This would be rare as you would have problems with the removal of the hub and bearings.

I would remove the races from the hubs and mic the inside diameter between the three and nine o'clock position, then at six and twelve o'clock and see if the hub is round. Could be that some grease monkey damaged the hub while installing the races.

Last item to check is the alignment of the rears. Not sure of a easy way to check a walking beam for alignment, but the bushings on that side might be allowing the rear under power to turn outward causing the side wheel to scrub causing the heat build up.

 

[garp]

Just a note of caution here. DO NOT use moly based grease for roller bearings. Moly is a solid and acts like an abrasive in a rolling or spinning application. It is only intended for use in turning(pins) or sliding movement. Use a good high-temp wheel bearing grease and save yourself some trouble. I realize some will argue this point, and even reference their favorite tube of grease and say different. Believe me, i see many roller bearings failed due to moly grease. Yes, they will live awhile, but will live alot longer with regular bearing grease. Same applies to fan hubs, water pumps and u-joints, etc.

As far as cutting off the spindle and rewelding a replacment on, dont bother. your still going to have to remove it and strip it out to cut off/weld on a new one. I would suggest finding a complete axle or housing and swapping your guts over.

 

[wvhillbilly]

From my parts store management experience, I feel that I can safely recommend any lithium based NGLI spec, EP (extreme pressure) grease. Find a parts store that sells Lucas Products, and buy Lucas "red" grease. It has the highest dropping point I have seen in a lithium based grease. Check out lucasoil.com for more info. Hope it helps.....

 

[wvhillbilly]

Garp is right, moly-based grease FRIES roller bearings. Stay away from anything that is graphite enhanced as well....

 

[Stretch44875]

If the axle is bent, an entire replacement axle can be found, I have seen them for about 350.

Just noticed you are as far away as you can get from me. No idea on prices/availability in your area.

 

[sermis]

Have you checked the brake adjustment? Too tight and it will get really hot and transfer the heat to the hub.

Tighten the nut up tight, back it off and retighten a good hand tight and try it again with out the outer seal.

 

[5tonpuller]

I had this same problem with my 5 ton. I turns out that the outer seals was to big. This made it rub and get hot. I checked the 6 seals I had and not 2 where the same size. ( go finger the QC guys ) well anyway I put the seal on my lath and took a few thousands off and went for a ride. The 3rd time was the charm. The seal had to be .500 thick to seal and not run hot.
Just my $0.05 worth.

 

[maddawg308]

Sorry, I thought this thread was about a hot tub at first. I guess I need my eyes checked....

 

[rosco]

If your assembly procedures are correct, the brake shoes are not dragging (you can rotate the assembly by hand), then your housing is bent, between the inside & outside bearing. This causes the mis-alignment of the two bearings. Is there metal flakes in the lube, when you dismantle the hub? Make sure its not a dragging brake shoe, where a damaged brake line is restricting the release of the brakes. To check that, after a short run, and its hot, jack up both ends of that axle & see if you can spin the wheels by hand. Another little trick is to roll the truck at a couple MPH, push the clutch in, & see how it coasts to a stop. A dragging brake will cause a more abrupt stop.

Lee in Alaska

 

[gringeltaube]

For the ones who think it's caused from dragging brake shoes, please read post#1 again.......

................It seems like its only the outer bearing. The end of the hub is hot, but the closer you get to the lug nuts and inner bearing, it gets cooler. The end of the hub after a run at 50 for 8 miles is too hot to touch for more than 1-2 seconds.
.......................................

 

[cleb]

Update #2. Took a little while because of school, but was finally able to wrench on her a bit more today. I pulled the seal off, and ran the nut right against the bearing, set it where it should be, added the locking ring and second nut. Went for a spin, and not nearly the heat as before! It runs very close to the hub on the other side. I think the axle flange and axle are dissipating some of the heat on the other side. On this side I can hold my hand on the hub as long as I want. Didn't melt the plastic bag on the end this time! gringeltaube, what do I need to do to this seal? It looks like the actual rubber part seats against the race correct? This is the 3rd one thats been on there. 1 New Star, one NOS (pretty old and hard, probably why it failed), and the current New Star seal (making it hot obviously). In any case glad its not a bad hub or spindle!

Thanks!

cleb

 

[gringeltaube]

............................................................................................... It looks like the actual rubber part seats against the race correct?.........................................

cleb

That's correct and that's how it's supposed to work!

It was exactly this brand ...... that I encountered problems with: too much "preload" and not nearly as flexible as it should be. Using a small press and some old bearings I did press the center portion of the seal (= mounting surface) IN-wards, about 1mm. It made a huge difference!

Tomorrow I will take exact measurements and pics to let you know.



G.

 

[tm america]

swap the hubs side to side if the other side gets hot you need a hub if the same side gets hot you need a housing the seal could be to tight which will fry the seal make sure you grease the seal to if you run it dry it will fry it to also make sure bearing are seated fully i tighten the bearings down by hand then tap on the hub with a hammer while spinning the hub .then tighten down with a small ratchet till you feel it drag loosen the nut and retighten by hand then install the lock and lock nut make sure when you tighten the lock nut it doesnt put drag on the hub

 

[tm america]

oh and as far as what grease to use .use wheel bearing grease or marine grease if you drive in alot of water it repels the water better and has the same characteristic as wheel bearing grease .also do you have duals or singles with the hubs flipped cuz your brakes may be dragging for some reason whuch will make more heat in that hubi if you have the hubs flipped you may feel the heat more in the outer side of the hub more if the brakes are dragging

 

[cleb]

gringeltaube: Would turning down the seal on a lathe work as well? Probably more work and would have to try a few times to get it right. Kind of interesting I installed a similar New Star seal on the other side and no issues with that one. So it goes...