This is my first post on the forums and, hopefully, I'm posting in the correct one 😆. We took up camping last year and found that packing everything into a car with 2 dogs occupying the rear was a bit of a struggle. So I purchased a used trailer which, although there is no identification on it, I'm sure is a Caddy 430. We have booked our first camping trip of the year at the beginning of May so have been getting things ready. One thing that didn't occur to me until recently was the need to change the bearings in the trailer. As I don't know if these have ever been done or the history of them, i thought I'd look at doing these myself prior to the trip for peace of mind.
So this weekend I decided to have a look to assess what was needed. The bearings the trailer has are the 6204-2RS sealed bearings mounted into cast hubs. I think I'm fine with getting a hub puller on these to remove (unless somebody wants to correct me) but my main reason for posting was to enquire on the refitting of these.
Do I mount everything onto the axle and use the castle nut and washer to "press" everything together (using a certain torque) and then back the castle nut off and re-do finger tight etc or is there another known procedure for setting this type of hub and bearing?
Any advice or suggestions would be gratefully received.
Do not use the castle nut to press the bearings into the head, the torque required to do that will likely damage the threads on the nut or shaft. Once you have removed the old bearings either use a hydraulic press to press the bearings into the hub or place a socket that is about 1mm-1.5mm smaller in diameter than the bearing on top of it with the open end against the bearing and gently tap the bearing into the hub, do not hit the bearing directly.
Also remember putting a new bearing onto a stubb axle to only tap on the inner part of the bearing not the outer or you will damage it also if fitting one into a brakedrum to tap the outer not the inner.
When I used to do car repairs many years ago there was a type of bearing that you did put in the way the O/P described. Tighten them in to a certain torque, then back off the nut, retighten finger tight and fix the castle nut with a split pin. However, it's years since I've done that and I don't remember for certain what type of bearings they were. They could have been taper roller bearings.
Thanks for your replies. So am i correct in saying that, after dis-assembly and clean up, I then press the 2 bearings into the hub - one from each side? Then take the hub/bearing assembly and slide this onto the axle (would it "slide" on or would it also need force to put it back on, possibly disturbing the bearings from where they have been pressed into the hub?).
I've looked on YouTube but struggle to find anything relative to my scenario. There's one I found which is installing sealed bearings but not using a castle nut. Some things I've read say to torque up to a given value (say 60nm) then back off and redo finger tight, others say tighten the castle nut until you feel resistance on the hub rotation, then back the nut off. Then others that you just do the nut finger tight but my concern with that was, as I've said above, how would I know the bearings are seated correctly after assembling onto the stub axle?
I'm thinking the difference may be whether they are parallel roller bearings or taper roller bearings. With taper roller bearings you will feel more resistance when you do the nut up tighter, whereas with parallel rollers or ball bearings you won't.
If you have one piece sealed bearings instead of two piece race and cage bearings then you press them into the hub and then tap the hub onto the shaft until the inner bearing is against the lip on the axle shaft. If you tap on the outer ring of the outside bearing the bearings should slide on and stay in place. Sealed bearings should not need much force to get them onto the shaft as the hub nut is tightened to a much greater torque than 2 piece bearings. Are you sure they are sealed bearings and not cage and race bearings?
If they are 2 piece bearings you do things slightly differently. With 2 piece bearings you press the 2 bearing races into each side of the hub and then slide the inner bearing cage onto the shaft tapping it gently until the roller cage is against the lip on the axle shaft. Apply grease onto the rollers and then slide the hub onto the shaft as far as it goes. Grease the outer bearing cage and slide it onto the shaft and into the outer bearing race. The axle shaft should be tapered and the bearing should slide on easily. You then fit the thick retaining washer and the castellated nut. Tighten the nut until all of the "wobble" is out of the hub but the hub still spins freely. If the hub feels tight to rotate back the nut off until it spins freely, the nut should only be finger tight, DO NOT over-tighten the hub nut, this will destroy your bearing very quickly. Finally, make sure the split pin is fitted and the nut cannot come undone.
Quote: Originally posted by russ-g-uk on 11/4/2023
Thanks for your replies. So am i correct in saying that, after dis-assembly and clean up, I then press the 2 bearings into the hub - one from each side? Then take the hub/bearing assembly and slide this onto the axle (would it "slide" on or would it also need force to put it back on, possibly disturbing the bearings from where they have been pressed into the hub?).
I've looked on YouTube but struggle to find anything relative to my scenario. There's one I found which is installing sealed bearings but not using a castle nut. Some things I've read say to torque up to a given value (say 60nm) then back off and redo finger tight, others say tighten the castle nut until you feel resistance on the hub rotation, then back the nut off. Then others that you just do the nut finger tight but my concern with that was, as I've said above, how would I know the bearings are seated correctly after assembling onto the stub axle?
You will know the bearings are seated in the hub properly as the sound with change when you tap them. When the bearings are fully seated you will hear a sharp hard sound and the bearing will not go any deeper into the hub. The bearings should not be very tight on the shaft and should only need gentle taps to get them on. The axle shaft will have a lip on the inner end and the inner bearing should be flush against this. The hub nut on trailers with sealed bearings is much higher than with 2 piece bearings, it is typically between 280NM-330NM (206 ft lb- 243 ft lb).
Somebody once asked me, is it easy to change a set of front brake pads on a car. My reply to that was how much experience do you have and what tools have you got. Their reply was that they had a couple of screwdrivers, a hammer and a few open ended spanners. My reply was in that case it's a difficult job and best left to the experts. Without being too critical this situation sounds very much identical in the fact that all the replies you can tell that all have some knowledge and experience in how to tackle the job of replacing wheel bearings. I've done it many times over the past years and I can tell you that a press is the most valuable tool you will need to press the bearing straight in on the out circumference of the ball race. If you apply any force just to the inner ring to compress a ball race bearing into place it will just dislodge the ball bearings inside the cage which will demolish the whole bearing completely. Personally I would leave this sort of job to the experts otherwise you could be doing more harm than good due to a lack of knowledge required.
Quote: Originally posted by martin734 on 11/4/2023
Are you sure they are sealed bearings and not cage and race bearings?
Thanks for your detailed reply Martin. They're definitely sealed bearings (pic attached hopefully). They may have been on there some time which is why they're not for coming off too easily. So I'll get a puller on them and, after giving things a clean up, hopefully everything will go on a bit easier like you say.
The nut setting is the thing that confuses me most on this one. If it was taper bearings I could totally understand having a castle nut and cotter pin to set them. Mine are sealed but if I was to apply the kind of torques you mentioned, I don't think I'd have any bearings left 🤣. When I was having a look at things the other day, I was giving the hubs a tap to see if they'd come off. As they didn't, I then had a play about with tightening the nut back up. I only applied a torque of 50nm and the hub was completely locked up with no rotation. So I may just insert the bearings into the hub, fit all onto the axle then just set the nut as you would with a taper bearing (ie finger tight then back off to the first split pin hole). At least they won't be going nowhere 😉
Quote: Originally posted by tango55 on 11/4/2023
Without being too critical...
No offence taken Tango, I value people's opinions. As you can probably tell, I'm not an expert in changing wheel bearings but I consider myself capable of doing such tasks with a bit of guidance - which is the reason I'm asking for all your help 😀.
Thankfully I do come armed with more than a hammer and screwdriver. I just don't have the press - thankfully work do have one so I may just have to assemble the hubs there 🤣
Quote: Originally posted by Colin21 on 11/4/2023
When I used to do car repairs many years ago there was a type of bearing that you did put in the way the O/P described. Tighten them in to a certain torque, then back off the nut, retighten finger tight and fix the castle nut with a split pin. However, it's years since I've done that and I don't remember for certain what type of bearings they were. They could have been taper roller bearings.
Thanks Colin. This was the reason I asked that question as I'm sure I've read a post somewhere saying to tighten up to a given torque which will ensure all bearings are seated correctly against their corresponding lips etc but wasn't 100% myself as to what bearings they were talking about but assumed that it was ball bearings similar to mine as I thought that applying a lot of torque to a taper bearing wouldn't be a good situation either 🤔😆
If the bearing is a taper roller bearing then the application of refitting is totally different. You have to grease the bearing first, place it in the cavity then screw the securing bolt on finger tight only. You then have to spin the road wheel and tighten up the nut respectively till you feel some resistance. You then back off the nut very slightly and spin the road wheel so there is no movement horizontally or vertically but spins freely. The science behind the fact is that bearings get hot with constant friction which the heat expansion has to be allowed for and only an experienced person knows how to apply the required allowance.
However, I wasn't been over critical in my last post, just the fact of being honest and truthful because I don't know from a person's post how much knowledge or experience they actually have which is very much like a teacher not knowing how clever each of their pupils are in class.
Quote: Originally posted by tango55 on 12/4/2023
If the bearing is a taper roller bearing then the application of refitting is totally different. You have to grease the bearing first, place it in the cavity then screw the securing bolt on finger tight only. You then have to spin the road wheel and tighten up the nut respectively till you feel some resistance. You then back off the nut very slightly and spin the road wheel so there is no movement horizontally or vertically but spins freely. The science behind the fact is that bearings get hot with constant friction which the heat expansion has to be allowed for and only an experienced person knows how to apply the required allowance.
However, I wasn't been over critical in my last post, just the fact of being honest and truthful because I don't know from a person's post how much knowledge or experience they actually have which is very much like a teacher not knowing how clever each of their pupils are in class.
Thanks Tango, I didnt take your post as being over critical or even critical at all. More like just giving your opinion which i appreciate. So could I ask, if you were replacing my sealed, non-tapered ball bearings, what would be your procedure for tightening the castle nut back up?