how do you like your nuts?

[mitchdemeanor]

I just went outside this morning to do some work on my trailer as i thought the wheel bearings were shot, but just as a quick check first i pulled the split pin out and had a go at tightening them, worked easily! Whoever had the trailer wheels off before me had practically only done the nuts up finger tight and popped the split pins back in, but it has left me wondering "have i now done up my nuts too tight?". I have tightened them up at approx firm hand tight tension just like i would my car, so do you guys think thats too tight or pretty much spot on?

[robothefisho]

"Fondled" But seriously, small shifter, do it up untill you actually have to try a bit to turn it, then back it off to the next slot in the castle nut. Hub should turn freely. If it doesnt spin freely you'll know it's wrong. There is normally only one position that will work. Sometimes there will be a slight ammount of play once the wheel is back on and rocked.

[oldboot]

I have heard people spout that wheel bearing nuts should not be nipped up on boat trailers..and I believe it to be a not uncommon view.

BUT....it goes against avery thing I have eveer be taught or read about wheel bearings

Tapered wheel bearings should not have any play in them at all........they should be snug, with the smallest amout of preload...and when adjusting you should wind the hub several turns as you tighten and before you settle in the tension being correct.

If they are not snug, the load is not properly distributed across multiple bearings in the race, (the load should be spread across all the bearings in the lower half of the race, each taking is sahre as it comes arround) there is opportunity for hammering in the bearings and it achieves nothing.....in fact if you are running bearings close to their capacity..which is almost every trailer I have ever seen.......the best thing to extend the life of you brearings is to keep right onto your maintenance...especially you grease and your bearing adjustment.

The justification for running bearings slack is that it is supoesd to keep the bearing cool......my view is that that is a load of carp.

If you are running blue marine grease of whatever brand ( lithium complex), the grease should stand any heat a trailer bearing could produce.....Unless you burn you hand when you touch your hub, don't worry about your grease or you bearings over heating.

I have seen plenty of rally cars come into checkpoints I have been manning with the disks glowing orange ,and never heard of any of these guys having a wheel bearing failure

Mitch mate...adjust your wheel bearings properly and with confidence.

OH..if that is how they have adjusted.....I'de be doing a bearing service and inspection sooner than later too.

All it will cost you is $12 for a pot of grease and a little time.



cheers

[Spaniard_King]

OB, the reason most people ERR on the loose side is they go overboard on the preload and doing so, you risk the chance of bearing damage.

So Mitch for you its wait and see if you are too tight :)

[oldboot]

Oh yes definitely.

But as robo says....on trailer axles there will usually only be 1 notch in the nut that will be rightish, and it will probaly be either a little tight or a little slack

And you have to take the time to feel.

If you repack a bearing and dont rotate the hub a few times as you tighten the nut...the bearing may feel tight and it isn't...of course after you have taken it arround the block....the bearing will be too slack.


The other situation that occurs to me may be an issue too.
Is when fitting new bearing cups into the hub....if the cups have not been driven home properly, as the trailer is driven the cups will get bedded and the adjustment will be slack.

So I recon if you have replaced bearings, you should recheck your adjustment after a couple of trips to the local ramp.


Consider that the bearing may have 1/2 a ton or more on it..so a few Kg of preload is not going to cause a problem......like wise a tiny little bit of play should no be a worry either.....

BUT

Slack sufficient to leave an audible knock is not good.

Take the time to rotate the hub few times get a feel for it and get it the best you can.

If in doubt......take it for a run arround the block a few times and check again.

After all it is a trailer ( a rough a butcherous device at best) and not a sports car that does 180KMH.

cheers

[Whitey81]

the bearings should have clearance. Do up the nut until snug tight and then back off until first hole. Go for a drive down the highway, check for excess temperature, jack up the trailer and check for side to side movement. At operating temperature should be spot on with no wobble or movement in the bearing assembly.

Having to much preload in the bearing is the best way to stuff them.

[trueblue]

the bearing should be looser rather than tighter. as most people don't know how much preload a tapered roller bearing can have (5/8 of sfa) it is better to be looser than too tight.

a very loose bearing will run from brisbane to cairns, but an over tight one might not make it to the local boat ramp..........

[oldboot]

Yrh but I have heard of a bloke that drove from brisbane to townsvile on rope and grease for a bearing.

One of my ford falcon manuals specifies the procedure as torqing the nut up to 30Nm and then backing off the nut 90 deg.
To achieve a bearing clearance of .05 to .2mm.
By the time you get some grease in such a clearance that will feel pretty firm.

consider any trailer over 750Kg will probaly be running ford falcon bearings.....that sounds like authorative.

remember too from my memory the threads on most car hubs are finer that the threads on trailer axles.

we go back to only one notch in the castelated nut being close to right.

And I'd hope to get a bit more than 1400Km out of a set of bearings....baring corrosion....I've had over 300 000 out of the bearings on the front of my van.

cheers