Trailer bearings too hot ?

Skinnyrib · 10 May 2012, 20:51

I've just taken my trailer for a spin to check all is OK prior to a long journey at the weekend - I stopped after 5 miles to check the temperature of the hub - one was slightly warm but the other whilst not hot was warmer -I could keep my hand on it no problem. Would any problems show up in a 5 mile road test - would it have reached maximum temperature on this 5 mile run ?

Thanks

thomas · 10 May 2012, 21:29

Jack it up and see how much play is in the wheel, if it's a really long journey and you've not checked them for a while then I'd take them out, check and grease.

Bigmuz7 · 10 May 2012, 21:29

If I understand your post and the trailer is empty, I'd say yes you have a problem .. pull the drums off and fix it, and save your self some heart ache, on your journey... could be just a stiff cable ? , and some lube will free it this time and you'll be ok till next season, but you would do well to check

Skinnyrib · 10 May 2012, 21:49

Thanks - boat on trailer - unbraked. I may have overtightened the one shot nuts (previous post) - but only nipped these up quite gently. Bearings in good shape. Wheels spin freely with no play at all. More grease ??

captnjack · 10 May 2012, 22:18

There should be a tiny amount of play in the bearings. Do not overtighten or they will fail prematurely.
There should be no free space in the hub at all, pack it full of grease.

Nick Hearne · 11 May 2012, 06:40

Quote:

Originally Posted by Skinnyrib

Thanks - boat on trailer - unbraked. I may have overtightened the one shot nuts (previous post) - but only nipped these up quite gently. Bearings in good shape. Wheels spin freely with no play at all. More grease ??

If you have one shot nuts you have sealed for life bearings which you are very unlikely to over tighten as they are quite different from tapered roller!

How have you stripped & checked them?

Skinnyrib · 11 May 2012, 07:42

Thanks - if I tighten the hub nut anymore the wheel won't turn ! The bearing is LM11749 - tapered. Took these into Indespension who said they were OK. Re- greased but running warm still...... ?? Setting off early tomorrow morning !!

spartacus · 11 May 2012, 07:55

Quote:

Originally Posted by Nick Hearne

If you have one shot nuts you have sealed for life bearings which you are very unlikely to over tighten as they are quite different from tapered roller!

How have you stripped & checked them?

My understanding of these 'Alko one shot' nuts is that they're not the torque 290Nm variety that usually accompany sealed for life roller bearings, rather as the OP has suggested, they are tapered bearings. They've been tightened to stop any lateral movement and 'one shot' nut applied. The nut goes on, is nipped up, then punched on both sides of the shoulder to engage with the slotted head on the stub axle. Double-check you've put the thrust washer on after the outer taper roller bearing.

Give me a castellated nut and cotter pin combo any day.

Once you've repacked with more grease Skinnyrib - then remember to use a new Alko nut!

Nick Hearne · 11 May 2012, 07:55

I think you may have over tightened them I put the castle nut on uptight then back off 1/4 turn.

Trailer Guy did a blow by blow acount on how to change them.

How to change a set of taper roller bearings PART 1

How to change a set of taper roller bearings PART 2

Nick

Trailer Guy · 11 May 2012, 10:22

sounds like they may be a bit tight, or lacking in grease. Difficult to tell remotely. Chech your tyre pressures too, if they're low they'll generate heat, due to the additional friction. So heat could be transferring back the other way to the hub, from the tyre, rather than out from the bearings.

one shot nuts and taper roller bearings is an unusual combination. Get them on a lot of yanky trailers, but not many uk ones.

As nick said, this may assist:

How to change a set of taper roller bearings PART 1

How to change a set of taper roller bearings PART 2

jyasaki · 11 May 2012, 15:13

FWIW, my trailer runs warmer on one side than the other. Always been like this. Same as yours: hub gets to about 90 degrees F from running (will obviously be warmer if ambient is warmer.) Doesn't seem to be any problem, and the disparity remains even after changing bearings.

jky

m chappelow · 12 May 2012, 20:31

If its only slightly warmer and on the nearside wheel could it be the road surface camber that causing it we had a number of trailers at work with this all the same side .

Skinnyrib · 13 May 2012, 06:13

Useful replies thanks. It transpires that I had overtightened the one shot nut - this was only a half to three quarter turn beyond finger tight. You have to resist over tightening before pinching the shoulder of thid small (24mm) type nut - some one shots need to be torqued - not this type !! I am a lot wiser and grateful to th eforum having reached my destination after 250 mile journey.

Trailer Guy · 13 May 2012, 09:41

Cheers for the update, will bear it in mind for the future!