Settting Trailer Bearings

davidpbo

Well-Known Member
Joined
14 Aug 2005
Messages
4,886
Location
Boatless in Cheshire. Formerly 23ft Jeanneau Tonic
myweb.tiscali.co.uk
Bringing the boat back today one wheel got warm another quite hot. I had serviced the brakes and bearings last week. I had stopped to check the bearings etc. after 5 miles or so. I thought it might have been because the layby I had pulled into was downhill so the brakes wold have been on and decided to drive on. Stopped a couple of miles further and the situation was much the same, I backed the brake adjuster on one wheel off a bit and drove to some services where these wheels were still warmer than the others. As I was in a safe place I decided to jack up and investigate. The brake was still binding slightly so I backed the adjuster of a tad more.

The other wheel the inner bearing of which I had replaced last week had too much play in it. I can only assume that despite taking care the bearing outer had not been seated properly. Anyway, I tightened it by hand and there was no discernable play and I went on my way without further drama.

How do other people set tapered bearings? The Indespension Trailer Servicing guide used to say torque the hub nut to a fairly modest amount and back it off a 1/4 of a turn which is more or less what I did, so there was no discernable play but the nut was little more than finger tight.
 
It is obviously important that the outer tracks are driven in fully. I use a brass drift and a decent sized hammer for this.

I tighten the nut firmly while turning the hub. The object being to make doubly sure that the outer tracks are fully bedded into place. I then back the nut off until just free and retighten by hand . I find this gives about the right amount of free play. It should be just discernable at the wheel rim.

Too much grease can cause over heating. I work grease into the bearing before fitting and put no more than enough to half fill the central space left when fitted on the axle between the bearings. Lakesailor would put in even less than this.

I find that the brakes have to be left with quite a bit of free movement
 
Last edited:
It is obviously important that the outer tracks are driven in fully. I use a brass drift and a decent sized hammer for this.

I tighten the nut firmly while turning the hub. The object being to make doubly sure that the outer tracks are fully bedded into place. I then back the nut off until just free and retighten by hand . I find this gives about the right amount of free play. It should be just discernable at the wheel rim.

Too much grease can cause over heating. I work grease into the bearing before fitting and put no more than enough to half fill the central space left when fitted on the axle between the bearings. Lakesailor would put in even less than this.

I find that the brakes have to be left with quite a bit of free movement

Another post deleted when I went to edit it.

Interesting what you say about grease. A friend of mine has grease nipples fitted to the bearings and pressurises them before immersion. A small hole in the bearing cap allows a little grease to escape when the bearing warms.

You can also get pressurised bearings.

Another friend who ran a company making wire wheels said you shouldn't tighten the hub nub too much initially (By which I mean proof to backing off) as it could damage it.

I had drifted the outer track in, I thought fully, but had obviously not got something right. The drift I use is so soft a steel it might just as well be brass.

Just as well I do check things once underway.
 
How do other people set tapered bearings? The Indespension Trailer Servicing guide used to say torque the hub nut to a fairly modest amount and back it off a 1/4 of a turn which is more or less what I did, so there was no discernable play but the nut was little more than finger tight.

The official method for Triumph Herald front wheels is to assemble the ungreased hub and tighten the nut until the wheel just begins to bind, then back off one flat. Mark that position, dismantle, fill with grease and reassemble to the same position. It will be very stiff indeed but soon loosens off just the right amount in service.

I use this method for trailer wheels and haven't lost or overheated one yet.
 
The official method for Triumph Herald front wheels is to assemble the ungreased hub and tighten the nut until the wheel just begins to bind, then back off one flat. Mark that position, dismantle, fill with grease and reassemble to the same position. It will be very stiff indeed but soon loosens off just the right amount in service.

I use this method for trailer wheels and haven't lost or overheated one yet.

That sounds familiar. Where you have a castellated nut with a pin you have some restrictions on where you can put the pin back in.
More "modern" practise often has the axle pin with a groove where you peen the edge of the nut lip . That's fine, but not really expected to be messed with before the car is scrapped. Trailer bearings are exposed to long periods of nothing followed by serious use. I just pulled a small trailer 340miles with a pile of stuff in it. No issues . I checked the bearings beforehand and found nothing out of order. Periodically you see trailers of some variety at the roadside with a collapsed wheel. Scary stuff...
 
I just pulled a small trailer 340miles with a pile of stuff in it. No issues . I checked the bearings beforehand and found nothing out of order. Periodically you see trailers of some variety at the roadside with a collapsed wheel. Scary stuff...

When I bought my crew a sailing dinghy on eBay I arranged to meet the seller 150 miles from his house. The trailer hadn't moved for 10 years and I reckoned that if it could get that far it would make the other 300 miles back to my place. Which it did, I'm glad to say, with nice new bearings which the seller fitted before setting off ...
 
The official method for Triumph Herald front wheels is to assemble the ungreased hub and tighten the nut until the wheel just begins to bind, then back off one flat. Mark that position, dismantle, fill with grease and reassemble to the same position. It will be very stiff indeed but soon loosens off just the right amount in service.

I use this method for trailer wheels and haven't lost or overheated one yet.

Not something I would want to be doing on a regular basis. Unfortunately with many trailers undoing the hub nut is the only way to get the hub off to inspect the brakes and get the rust off the inner drums, so I would not want to be removing all the grease each time.
 
I usually drive the outer race in with the old one with a slot cut in it so it doesn't jam or a good sized socket so your not touching the face of the race, just use a bit of wood between this and the hammer, a press is obviously the best way but either way double check it has seated properly.
 
I just pulled a small trailer 340miles with a pile of stuff in it. No issues . I checked the bearings beforehand and found nothing out of order. Periodically you see trailers of some variety at the roadside with a collapsed wheel. Scary stuff...

But you checked the bearings before hand (As did I which is why I replaced one that was rumbling a bit). I doubt even if the trailer is out in the rain water gets into the bearings. The problem with boat trailers as we all know is they are immersed then often left left to stand for days/weeks/years which is why it is prudent to check them regularly.

With regard to the collapsed wheel at the roadside, it is not a situation I want to be in. I do carry spares and the wherewithal to use them but if not appropriate recovering the boat and trailer would be v.expensive. I will look at other roadside assistance organisations at the end of the year
 
Where you have a castellated nut with a pin you have some restrictions on where you can put the pin back in.
More "modern" practise often has the axle pin with a groove where you peen the edge of the nut lip . That's fine, but not really expected to be messed with before the car is scrapped.

My first experience of the "peening" system was two months ago when I replaced the bearings, kingpins, oil seals, track rod ends etc on a Japanese 4WD.

The workshop manual explained that I needed to "uncaulk the front wheel bearing lock nut". I had no idea what that was supposed to mean and spent a few minutes looking at the hub wondering what they were talking about. Then the penny dropped .... they mean "hammer out the peening". :)

I don't know whether that's just a poor translation from Japanese or a problem with my limited vocabulary?

Richard
 
Not something I would want to be doing on a regular basis. Unfortunately with many trailers undoing the hub nut is the only way to get the hub off to inspect the brakes and get the rust off the inner drums, so I would not want to be removing all the grease each time.

That's the set-up procedure. After an inspection I would just put them back to where they were.
 
From my experience with tapered trailer (car) wheel bearings I don't imagine the heating of the wheel was from the bearings at all. More likely the brakes. However it is vital to jack the wheel off the ground and just check for turning friction. This should not come from the bearings. But not from brakes either. The problem with brakes is that they can be applied while driving and may not always release. So heating up the wheel.
Re not much grease in the bearing I hear what what is said. However what is popular around here is a cap with a spring loaded piston. The spring and piston provide a positive pressure iside the hub. They can take any expansion with heat then sink in to maintain pos pressure on cooling (in the water).
Now I always assumed the whole hub was filled with grease. But perhaps it is just air with a little grease?
Renewing bearings, perhaps I am just lazy but find that renewing just the removable roller race and the one cup on the axle will get me a reasonable bearing with little work. Hard job bashing out the fixed cup.
I always remove the wheel by removing the hub nut not the wheel nuts. I check before any road trip.
Though I confess mostly my trips are short so bearings are pretty rough but OK for short trip. (and brakes are removed. But that is just me . good luck olewill
 
RichardS, I always read that word as uncork, in other words undo.

I agree that it's pronounced the same as uncork but it can't mean "undo the front wheel bearing lock nut" because you can't actually undo it unless you "unpeen" it. I tried turning it but I found that it jammed against the peening which is when I realised what "uncaulking" meant, in Japanese at least! :)

Richard
 
I agree that it's pronounced the same as uncork but it can't mean "undo the front wheel bearing lock nut" because you can't actually undo it unless you "unpeen" it. I tried turning it but I found that it jammed against the peening which is when I realised what "uncaulking" meant, in Japanese at least! :)

Richard

A tip which may be useful if you have to unexpectedly do any work on hubs where the retaining nut is staked .......... thats the word not corked or caulked

Because you cannot (reliably ) reuse them swap the left side one with the right side one and with luck they will be restaked in a different position . Done it regularly with the rear hubs one one of my cars when the brake shoe inspection has fallen due.

You can only do it once of course ... then you need new nuts.
 
As far as I am concerned the more grease in the hub, the less room for water when immersing the trailer.

I can sympathise with that. Bearings often say "do not overpack" or "pack to 50%" but I've had to change dozens of bearings which had run dry of grease but I've never had a bearing fail due to there being too much grease. I certainly agree that in hubs which spend time immersed in water (launch trailer and off-road 4WD bearings) I would much rather have too much grease in the bearing than any water!

Richard
 
Top