Trailer Wheel Bearing Castle Nut - How Tight?
I've searched but I can't find the answer. I just changed the bearings and races on my 2002 Ramlin" single axle trailer and I have a question on how tight the castle nut should be. To set the bearings, I used a wrench on the nut and then backed it off a little bit and locked the castle nut in place. My question is on the tightness of the castle nut to get rid of all play on the wheel when you wiggle it. To get rid of all of the play, the nut is almost as tight as you can go. If I back it off a little more, I get an ever-so-slight wiggle on the wheel (when it is jacked-up and off of the ground of course). Is a very slight amount of wiggle OK? I think the wheel seems to spin the same either way, but it is hard to tell slight differences when turning by hand. I just feel that the nut is almost as tight as it can go when the wiggle completely disappears. I've read that you should back the nut off a 1/2 turn or so, but this seems to be too much. What do you guys do?
This is a brief rewrite of what my Dexter axle book says.
Tighten the castle nut to 50 Ft-LBS, while turning the hub several revolutions, both backwards, and forward.
Without turning the hub, loosen the castle nut until it is free, and then tighten it finger tight. Back it off until the first castellation will take a cotter pin.
Put the cotter pin in.
This gives the bearings a slight amount of "freeplay"
You definitely do not want any wiggle in the hub. Finding the perfect balance between eliminating the slop and overtightening can be tricky. You want the wheel/hub to spin as freely as possible, but without any play/wiggle. Like Dan said, that usually means getting the castle nut just finger tight.
Thanks for the replys guys.
The amount of wiggle I am talking about is very slight when I loosen the castle nut a very small amount. If I grab the hub with the tire on it, I can feel the hub "rock" back and forth ever so slightly. If I go tight with the wrench, it stops. I then can only back it off a very small amount before the "rock" returns. the rock is not much, but it is there. Just not sure if any should be there. If I follow what the Dexter axle book says, then I will definately have some movement. Not sure just yet on how tight to go.
Overtightening and allowing the hub to be too loose are both recipes for disaster... but allowing the bearing to flop around on the taper sure seems like a bad idea to me. I would err on the tight side, rather than the loose side. Keep a close eye on them the first few miles- keep checking to make sure theyre not overheating.
I assume you have the correct size bearings? Slightly mismatched sizes will not seat properly and will always be loose, or overtight. Like if you were to install 1.04" bearings on a 1.00" axle. Dont ask me how I know this!
I've heard the opposite...slightly loose being better than too tight. Its amazing how just a quarter turn too much makes them heat up more.
The instructions I follow are similar to those that DanielC posted above.
Note - I just had my trailer at a professional trailer shop and all wheels have a barely noticeable amount of side to side play...but they don't clunk or wobble. I've driven it at least 1K miles since then.
Loose is better. Usually tighten as much as u can with fingers and back off a little. Plenty of YouTube how to-s