Forum Discussion

myredracer's avatar
myredracer
Explorer II
Sep 30, 2015

trailer bearing, seal & spindle questions

If comparing bearing temperature after a leg of a trip, how much higher would the temp. of a bearing compared to the other 3 (tandem axles) have to be to be considered running too much hotter - 10F, 50F, 100F? (Measuring using an IR gun pointed as close to the center of the drum as possible.) Having an issue with one bearing that is hotter/warmer than the others.

I removed one "good" wheel and found that the nut appeared to be over-tightened. I needed a wrench to loosen it with more force than I would have expected was needed. I thought the nuts were supposed to be close to being finger tight when installed?

I am guessing that the suspect wheel has a nut that was tightened too much. Our dealer was supposed to have done a complete overhaul so I am assuming they did not re-install the hubs correctly.

Bearings being too tight or being loose is not good, but I recall one is worse than the other. Is being too tight bad? I've got a complete set of new bearings (USA made!!) so would it be okay to keep one set for an emergency repair if out on a road trip? The bearings have maybe 8-10K miles on them.

Noticed the underside of the spindle is rusty looking as in photo. Not sure if it is corrosion or caused by overheating from spun bearing? I recall someone posting about this about a year or so ago on their TT and can't recall what the outcome was. Not sure if it can be ignored or not.

Is seal quality a concern? Can't find Dexter ones on the shelf locally and would have to wait up to a week. Bought a set of unknown & unlabeled ones anyway that I can always keep as spares or return. They're from the local supplier of Dexter parts to RV dealers, but that doesn't mean they're good. Don't even say Ch*na anywhere while the Dexter's do.

  • westend's avatar
    westend
    Explorer
    Sep 30, 2015
    To answer the primary question, yes you have it right, axle bearings should never be over-tightened. I read on this Forum where some guys choose to leave them very loose, to the point that the whole wheel assembly has some play, forward and back. IMO, that isn't right, either. A good installation will have the wheel assembly spinning freely but there will be no play.

    Keeping a used bearing will be your call. If the bearing seems to turn correctly and there is no evidence of pitting or galling, you could certainly keep it for a spare.

    IMO, too much attention is given to country of origin. As long as the part is a name brand, there shouldn't be an issue. You could take the loose seal and see how it fits around the spindle. If it is concentric and rests against the spindle, again, no worries.

    Just an impression I am getting here. Folks on this Forum that are messing around with axle bearings are new to the game. Torque specifications and different grease formulas are discussed like bearings were a part of a NASA project. I guess I grew up servicing axle bearings and learned what worked and felt right about them. I've never used a torque wrench to seat an axle bearing. Back in the day, all vehicles had serviceable axle bearings and most guys with a wrench in hand learned bearing and seal installation.

    BTW, that picture of the spindle depicts a burnished spindle. The bearing on that spindle was failing to the point that it heated and changed the color of the metal (blue). I wouldn't worry about light rust that the picture depicts. That isn't going to effect the function of the bearings on the spindle. If it worries you, clean it off.
  • MFL's avatar
    MFL
    Nomad II
    Sep 30, 2015
    Hi Gil,

    There are many opinions concerning proper bearing adjustment procedures, but I will give you mine. I would tighten the castle nut to about 50 lb. ft., to set the bearings. No you don't need to use a torque wrench to be exact. Then I would back the nut loose, finger tighten it, putting the cotter pin in the slot available, without having to tighten it further.

    As far as heat gun temps, I would not worry about 10* variance. At 50* difference, I would be concerned, could have a brake dragging, or a too tight bearing. At 100* degrees, something is wrong, brake/bearing, needs attention.

    It would be okay to use a used bearing in an emergency. Normally the bearing should be matched to the race it has been run on.

    Myself, I would be sure to use the proper seals at replacement time. I called Lippert about mine, knowing I would be replacing them. I couldn't find exact replacement locally. They said an exact replacement would be hard to find, but they could send what I needed.

    A little off topic, and I know also many opinions, but I think that some of the EZ-lube seal failures, are due to someone replacing the double lip original seals, with whatever the parts guy gives them. The next owner of the trailer has no idea what seals are installed when he uses the EZ-Lube feature.

    Hope all goes well for you,
    Jerry
  • RJsfishin's avatar
    RJsfishin
    Explorer
    Sep 30, 2015
    Greased bearings w/ a preload are too tight. Some bearings that run in oil, do call for a preload. If too tight, there is no room left for grease, and they will run warmer.
    Bearings w/ any roughness or pitted will also run warmer.
    Wheels should run freely, w/ little to no play would be correct.

    Seals, no biggie, as long as they press into the wheel, and they push onto the "seal surface" w/ some resistence.

    Jack up each wheel, spin it, you should be able to tell the problem by comparison
  • TakingThe5th's avatar
    TakingThe5th
    Explorer
    Sep 30, 2015
    X2. A little trick I learned about tightening the spindle nut was to try moving the washer behind the nut with a screwdriver, gently of course. If it won't move - too tight. If it moves too easy - too loose. Be sure to rotate the wheel as you tighten it up to make sure everything is seated correctly. Then back off as necessary to find a hole for the cotter pin.
  • Bill_T's avatar
    Bill_T
    Explorer
    Sep 30, 2015
    Do you have access to a bearing supply house? If so you can find quality seals and bearings there. We have Industrial Technologies in my area. I've always had good service with Timken bearings/races and Chicago Rawhide seals. Give the people there the numbers off your parts and they can cross reference to a better grade part if that is what you would like to do.
    I also subscribe to the looser is better than tighter method. Tighten the castle nut as tight as you can get it with a 12" adjustable wrench, then loosen the nut, then retighten by hand until the nut touches the bearing and insert the cotter pin in the closes hole.
  • Lynnmor's avatar
    Lynnmor
    Explorer
    Sep 30, 2015
    You should not need a wrench to loosen a spindle nut. They are to be adjusted with a very small amount of clearance and therefore there will be no resistance to remove. Once again, you found out that you have to do any and all work to the trailer.

    Your photo isn't quite clear enough to judge the wear pattern on the spindle. I enlarged it, and see what looks lire a step outboard from the wear mark. If that is the case, the spindle is hosed. The bearing should be a slip fit with no play. Put the old bearing back on and check for looseness, or better yet check it with a micrometer. It is normal to get some darkening in that location, so when resembling apply a film of grease over the entire spindle to help prevent this in the future.

    When assembling, apply grease inside the seal and and between seal lips so it doesn't run dry against the spindle. Of course, be careful that you don't use so much that it lubes the brakes.
  • phillyg's avatar
    phillyg
    Explorer II
    Sep 30, 2015
    If three hubs are measuring say, 120, and one is 170, then you might have an issue. A 100 degree difference is almost certainly catastrophic. The rust on the spindle just means there was no grease at that location and is no problem. But your spindle appears to have been heat stressed. I'd have an expert take a look at it before your next trip
  • NinerBikes's avatar
    NinerBikes
    Explorer
    Sep 30, 2015
    TakingThe5th wrote:
    X2. A little trick I learned about tightening the spindle nut was to try moving the washer behind the nut with a screwdriver, gently of course. If it won't move - too tight. If it moves too easy - too loose. Be sure to rotate the wheel as you tighten it up to make sure everything is seated correctly. Then back off as necessary to find a hole for the cotter pin.


    This/\ Tension is correct if you can move the washer with a little bit of resistance under the set nut, with a screwdriver pushing the washer side to side.

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