Help Please - Can't Get HF Hub on Axle

[jseyfert3]

Okay, I'm stuck. I can't get the hub on the axle for a HF 1720 lb trailer. Wiggle, push, wiggle, push, just won't go anywhere. I even tried (very carefully!) tapping around the hub with a hammer, nothing. The hub has greased bearings and the bearings and grease seal are in place. It's sticking up on the rear bearing, it just won't fit onto the axle.

First hub went okay, it's on the trailer and ready to go. Did it the same way, greased bearings, grease seal. It didn't want to go either. After a bit of pushing and wiggling, I let off on the force a bit, debating to break out the hammer or ask here...and it slid right on. When it got up to the front bearing I just had to wiggle it slightly and it went right on. So I figured the second hub should be the same, wiggle for a bit and it'll eventually go on. But it's not going on.

So, what gives? Anyone else had this problem?

[KennethW]

I hope you cleaned and re-greased the bearings. The stuff on the bearings is not grease!!
When packing a bearing the grease has to be pushed through the bearing. Put a glop of grease on the palm of your hand then take the bearing in the other hand and pound the grease through the bearing until you see the grease squeezing out between the rollers. Did you check the axle for dinks and dents. A very small dent will stop a bearing from going on. Try the bearing by it self if you can to see if that may be the problem.

[Redneck Teepee]

I'm sure it's a QC problem and/or can be fixed with a little emery cloth. If you have a set of calipers you can check the spindle dia. vs the inner bearing bore dia. Bearings are usually within a 1 to 2 thousands fit on the loose side and some times as Kenneth said a little nick will prevent them from sliding on.

[jseyfert3]

Yes, they were cleaned and greased with new grease seals.

I can't pull the hub back off either. I tried holding the trailer with my feet while sitting on the ground and pulling the hub with both hands. It won't budge. I notice the grease seal bulging when I pull, by the time I get it off it's going to need a new grease seal.

If there are no nicks, what do I do then? I have some digital calipers, if I can get the hub off with help from my roommate later then I'll measure stuff up.

[Redneck Teepee]

Yes, they were cleaned and greased with new grease seals.

I can't pull the hub back off either. I tried holding the trailer with my feet while sitting on the ground and pulling the hub with both hands. It won't budge. I notice the grease seal bulging when I pull, by the time I get it off it's going to need a new grease seal.

If there are no nicks, what do I do then? I have some digital calipers, if I can get the hub off with help from my roommate later then I'll measure stuff up.

After confirming with your calipers that you are within .001 or so too big on the spindle,take the emery cloth and tear off about 12" worth then go around the spindle evenly all 360 degrees worth like you are shining/buffing a shoe so to speak or using a cable saw. I prefer the waffle pattern emery cloth because it is a little better at self cleaning, you local plumbing supply/hardware store should have it. If it's more than a thousand or so difference you got bigger problems than what emery cloth can fix.

[jseyfert3]

Yes, they were cleaned and greased with new grease seals.

I can't pull the hub back off either. I tried holding the trailer with my feet while sitting on the ground and pulling the hub with both hands. It won't budge. I notice the grease seal bulging when I pull, by the time I get it off it's going to need a new grease seal.

If there are no nicks, what do I do then? I have some digital calipers, if I can get the hub off with help from my roommate later then I'll measure stuff up.

After confirming with your calipers that you are within .001 or so too big on the spindle,take the emery cloth and tear off about 12" worth then go around the spindle evenly all 360 degrees worth like you are shining/buffing a shoe so to speak or using a cable saw. I prefer the waffle pattern emery cloth because it is a little better at self cleaning, you local plumbing supply/hardware store should have it. If it's more than a thousand or so difference you got bigger problems than what emery cloth can fix.

Okay, thanks. Will do. I won't be able to work on it till tomorrow night or Monday morning though, I'll report back then.

I expect that pulling off the hub will end up ruining the grease seal. Hopefully not but it seems likely. Good thing I ordered 10 of them!

[KCStudly]

Are the inner and outer bearings the same ID, or is there a step in the axle stub with the inner bearing having a slightly larger ID?

In the latter case there is a possibility that the cone (the inner race and bearing cage) of the inner bearing was not centered in the cup (the outer race) and when it approached the taper of the stub is cocked and wedged.

Did you wipe some grease on the spindle before attempting to slide the hub on?

Don't worry about the seal, especially if you have plenty of spares. It might even be beneficial in diagnosing the problem if the inner bearing stays on the spindle when you do get the hub off. If it is cocked or dug in on one side (or top/bottom) there should be a mark or scuff enough to see. If it is just a hard fit (too tight) then you might be able to see an annular mark even all around. If it was something foreign or a raised burr or dent, once you get the bearing off and everything wiped clean you should be able to see it or a shiny spot.

Sorry if my suggestions are more generic. I am not so familiar with these kit trailers, but I have lots of mechanical experience. The problem will present itself. Be patient and look at everything very carefully with a critical eye. I few very light/gentle taps with the hammer probably didn't do much harm; but it should not have come to that.

[jseyfert3]

Are the inner and outer bearings the same ID, or is there a step in the axle stub with the inner bearing having a slightly larger ID?

The end of the axle is machined to the same diameter from the edge of the castle nut threads almost to the axle tube. Right before the machined end of the axle is welded into the axle tube, there is a step and a short section of bigger diameter that the grease seal (not the bearing) fits over. The bearing would slide up to the edge of this and stop. (assuming it would even get on the axle in the first place )

In the latter case there is a possibility that the cone (the inner race and bearing cage) of the inner bearing was not centered in the cup (the outer race) and when it approached the taper of the stub is cocked and wedged.

I was actually wondering myself if the bearing got started a little crooked and then got jammed on from pushing and/or tapping with hammer.

Did you wipe some grease on the spindle before attempting to slide the hub on?

I did, on both sides, after wiping the axle off with paper towel to make sure there was no junk sticking to the oil that was on to prevent rusting after machining.

Don't worry about the seal, especially if you have plenty of spares. It might even be beneficial in diagnosing the problem if the inner bearing stays on the spindle when you do get the hub off. If it is cocked or dug in on one side (or top/bottom) there should be a mark or scuff enough to see. If it is just a hard fit (too tight) then you might be able to see an annular mark even all around. If it was something foreign or a raised burr or dent, once you get the bearing off and everything wiped clean you should be able to see it or a shiny spot.

I was actually considering seeing if I could fit my seal puller on the seal without the trailer/axle getting in the way, pulling the seal off, and sliding the hub off and see how the bearing is currently stuck on the axle. The reason I thought it might have gone on crooked was because with the first hub's dust cap I broke out the rubber hammer to put the cap on, and it wouldn't go straight in, it always went crooked and then stopped moving in. I ended up using a wide flat screwdriver and gently tapping all around the edge a little at a time to work it in, that worked just fine.

Sorry if my suggestions are more generic. I am not so familiar with these kit trailers, but I have lots of mechanical experience. The problem will present itself. Be patient and look at everything very carefully with a critical eye. I few very light/gentle taps with the hammer probably didn't do much harm; but it should not have come to that.

No problem, I appreciate the help. I know I really shouldn't have broken out the hammer, but I was getting frustrated that it would not go on. Even before the hammer though, it didn't want to come off, although at that time I didn't try super hard to get it off.

Okay, when I can (Sunday night or Monday morning) I'll try the seal puller if there is enough space to use it, which will allow me to see how the bearing is stuck. Also, I have some pictures but not with me, they probably would have been useful for those who don't know about HF trailers like KCStudly, and I will definitely take pictures once I get the hub off.

[KCStudly]

Another thing to look for once you get it apart (but that would not account for them getting stuck) is if the inner cups/races are not fully seated in the hub. There was at least one case reported of the seal not riding on the seal mating surface and that was traced back to the inner bearing races not being fully seated. This would quickly result in a bearing failure; once the cup shifted and seated itself, the bearings would get very loose and fail.

[jseyfert3]

Another thing to look for once you get it apart (but that would not account for them getting stuck) is if the inner cups/races are not fully seated in the hub. There was at least one case reported of the seal not riding on the seal mating surface and that was traced back to the inner bearing races not being fully seated. This would quickly result in a bearing failure; once the cup shifted and seated itself, the bearings would get very loose and fail.

From cleaning the hubs before greasing them, I'm pretty sure all four bearing races were fully seated.

[jseyfert3]

Okay, got the hub off since I didn't need to save the seal. I managed to get my seal puller inside and pull the seal out, at which point the hub came right off, as it should. This is what it looked like at that point.


Axle Immediately After Pulling Hub by jseyfert3, on Flickr

I wiped off the grease around the bearing and the end of the axle shaft, and it appears the bearing is somewhat crooked.


Wiped Off Some Grease, Bearing Appears Somewhat Crooked by jseyfert3, on Flickr

Another angle.


Another Angle by jseyfert3, on Flickr

I used a wide flat screwdriver and a hammer to tap off the bearing, alternating between sides to push it off as straight as possible. The axle shaft looks good, with no obvious nicks that would have caught the bearing. You can see the slightly angled vertical lines from the bearing on the shaft.


Axle After Bearing Removal by jseyfert3, on Flickr

There was one nick I found, but that was caused by my seal puller. This angle shows the imprint on the axle shaft left by the bearings as well. I think that shows up better then the above picture.


Nick Caused by Seal Puller by jseyfert3, on Flickr

As requested, I measured the axle shaft and the ID of the bearing. I got 24.96 to 24.97 mm ID on the bearing. On the axle, I got between 24.96 and 25.04 depending on where I measured on the axle and the axis I was measuring across. That's a difference of up to 0.08 mm or 0.003". This was measured with my $15 digital calipers, not a $200 micrometer, so keep that in mind.

Is it time to go pick up some emery paper and go to work on the axle? Or is the difference too much for simple emery paper?

[eamarquardt]

If yer using HF calipers all readings are suspect. I've abandoned them for anything other than getting close. For serious machining I've found the HF ones I've purchased useless and bought a new pair of Mitotoyo digital calipers and dug out my older Mitotoyo dial calipers.

If you can get the bearing started onto the shaft at all yer pretty close. I'd take a nice flat board, glue some emery 120 or so grit emery cloth to it and gently and gradually work on your spindle with it till the bearing slips on and off. Given you'll only be working on the ridges left by the cutting tool on your spindle I don't think it will be much work to get the bearing to slip on and off.

In your picture it looks like there is some paint on the surface where the seal rides. I'd clean up that surface also.

Cheers,

Gus

[KCStudly]

So first, the bearing won't slip on by itself no matter what you do, right? Option one is to take the whole thing back and complain.

Option two, save yourself the hassle, and fix it! There is a small risk that you can do some harm, but that's what makes fixing things so rewarding!

See all of those spiral tooling marks on the main part of the stub shaft? That means that they had the feed up as high as they could and still get a "passable" finish. What you have there are highs and lows where the tip of the cutting tool didn't touch everywhere as it passed by, or at least was pushing material out of the way like a wave rather than cutting. A higher quality shaft would have been cut with a much slower feed rate resulting in more of a polished appearance.

Your desired dimension is probably somewhere between the high and low points, so you need to be careful not to sand off too much material or you could go undersize real quick. At first you will be sanding off just the tips of the peaks and it will go faster so be careful.

For the nick(s), I would hit those one or two little burrs with a very fine flat file (or some sand paper backed up by a paint stir stick, or equal) just gently to make sure there is not a raised spot. Don't try to make the mark go away, the lows aren't going to hurt anything, but the highs will stand out as shiny spots when you hit them with a hard back or file. If there are any, take them down until they match the surrounding area. You're not chopping down a tree with an axe, so go easy. Shouldn't take but a slow stroke or three, really delicate. Make sure to hold the file flat to the diameter (perpendicular to the axis of the stub) before you start a stroke and roll it around the diameter slightly with the stoke to follow the contour. Don't make a flat spot, don't push hard at all (let the file do the work), and don't try to run the file onto the shaft on the fly or you might come down with the corner of the file first and dig a corner in.

Clean all of the file dust up well and if the bearing slips on now, you're done; proceed with assembly.

If the general oversize condition persists and still prevents assembly, follow the advice above about wrapping the emery around the stub and dragging it back and forth like you are doing a shoe shine. With each pull you should be making the emery walk along the shaft as well, and constantly changing positions so that you work around the circumference and along the length evenly. Check your work often with the caliper and by trying to slide the bearing on by hand. Keep things round and don't go undersize.

Once you are good to go, write up an honest review on the trailer suppliers website or contact them and let them know what you went thru. If you are polite and ask nicely, they may offer you a coupon or discount on your next purchase.

OT Alert: Reminds me of the time in the shipyard when we had string of 688 class HIPAC (high pressure air compressor) connecting rod bearing failures on initial start up. Wiped out both rod pins on the crankshafts; 3 boats in a row. Mind you, the HIPAC's on submarines are considered SUBSAFE equipment because they make the air used to blow the ballast tanks and can potentially save the ship. Rather than fully disassemble them to replace the cranks (with a corresponding schedule delay), my colleague and I worked with the outside machinist for a couple of days straight reaching thru the access panel into the crankcase and hand stoning the journals back into spec; round and parallel with the proper finish and end radii, measuring eight radial and eight longitudinal locations for a total of 64 readings per journal. Those were the days.

[jseyfert3]

I went to the hardware store and picked up a roll of 1" x 10' emery paper, 120 grit on the suggestion of the employee after he asked what I was doing with it. Cut off a 12" long piece and went to work, "shoe shining" my axle.

After a bit, I was rewarded with the bearing sliding on after I wiggled it a bit. It didn't go all the way on, most of the sanding was focused on the front to just get the bearing on the axle. You can see what's sanded and what's not by the texture difference.


Slid On; Not Completely Though by jseyfert3, on Flickr

A little bit more sanding near the end of the shaft and it slid all the way on. It still needed a little wiggling at the start to get on, and I noticed the lip by the threads was somewhat sharp, so I used a file at an angle to knock the edge off, and when I went to put the hub on, the bearing slid right on, no wiggling required.


Completely Seated by jseyfert3, on Flickr

I found another very minor issue during the subsequent assembly process, the slot I needed to put the cotter pin through the castle nut was way off, in just that side. Too far off to allow the cotter pin to go through. Who was running the machines at the factory that day?


WFT? by jseyfert3, on Flickr

Luckily, as I said, that was very minor, and careful use of my angle grinder and a cutoff wheel fixed it in a minute.


Fixed Slot by jseyfert3, on Flickr

I then put the castle nut on, the wide slot is not an issue, the nut is still unable to turn.


In Place by jseyfert3, on Flickr

And just after that, I had the dust cap in place, finishing hub #2!


Finished! by jseyfert3, on Flickr

With the exception of bolting the trailer ball coupler in place with four bolts, installing the tires, and painting the tongue, this completes work the trailer itself and work on the Teardrop can officially begin. I plan on doing that today, after I sleep. I'll also need to wire up the included trailer lights, even though my TD won't use them, because I'll be using this trailer to go get some OSB and 2" foam sheets later today.

Thanks all for the help, much appreciated.

Once you are good to go, write up an honest review on the trailer suppliers website or contact them and let them know what you went thru. If you are polite and ask nicely, they may offer you a coupon or discount on your next purchase.

Perhaps so, but I'm thinking probably not. The trailer is a Harbor Freight trailer, about the cheapest trailer you can buy. Using a 25% off coupon which they hand out like candy, I bought the trailer for $290, including tax. Between being a chain discount (cheap) store and them already handing out 20% and 25% coupons left and right, I doubt I could get a discount. It doesn't hurt to ask though, so I may check anyhow.

[Redneck Teepee]

Good Job! Where there is a will, there is a way. Kc was spot on about the feed speed during the machining of that spindle, and with almost all production work being done on CNC equipment nowdays, I'll bet your spindal has a few brothers and sister's out there giving someone else fit's too.