Dust Cap Woes

[airshot]

I would add sealant if you're going to salvage the current caps with dimples.

Just add a couple small dabs of Goop and let sit over night and you will be good...easy off if you just use a tiny couple dabs

 

[l008com]

I bought another set of caps today to replace the latest one that fell off, and I eventually got it in there without any modification and from what I can tell, no damage either. Hopefully this one stick and this problem goes away! The first one went in within 5 minutes, so now I have a spare! As opposed to the normal situation where I have no spares and 4 destroyed ones in the trash can

 

[Drcoffee]

As someone mentioned above ditch the steel caps and use rubber dust covers. I use two zip ties with locks 180 degrees apart. No water intrusion all summer.

 

[Horigan]

I think another advantage of rubber caps is that it will compensate for the thermal expansion and contraction of the air in the hub and would mitigate to some degree the vacuum that can be created when warm hubs are dunked.

 

[ESGWheel]

l008com,
I throw in my 2 cents for what its worth.

Frist off for the suggestion about the dimples by @bruceb58: here is a video showing the where and how, link. Skip to minute 2:30 for the dimpling event. But if you watch the entire vid, you will see that (1) his caps are loose from the get-go and (2) the caps have a very short length of engagement. See below pics for what I mean about long and short engagement.

Are yours ‘loose’ like in the vid? I am going to assume you have used a variety of caps both long and short. But if not, look for the long style.

Also, as alluded to by @Horigan: thermal expansion. It may be the cause of popping off caps. If your caps fit on what seems to be tight and proper (i.e. not loose like it the video) but you keep losing them, perhaps heat is expanding the grease and causing them to pop off. I have seen this happen in my auto mechanic days. Two potential causes for this: (1) the entire hub is overfilled including the cap and/or (2) the bearings are heating up excessively. There are a lot of different opinions out there about item 1 but air can compress and grease cannot. If no air space at all, well, you lose a cap or (more likely) ooze grease out of the rear seal. Note that bearing buddies are by design 100% filled but also have a spring-loaded piston that will allow for expansion.

Also, I do not subscribe to the idea of a worn hub due to age. Hub is cast iron and hard; dust caps are thin and soft. Even if pulling one on and off a 100 times I suspect the only thing wearing out is the cap. Of course, if there was rust build up in this area and it was ‘cleaned up’ then that can cause the hub diameter to be larger where the cap fits. Back to the question: do the caps fit loose like in the vid or on nice and solid?

More: I would not add sealant or other products other than Loctite 638, link. This product is designed for a loose-fitting part. Of note is that while the product literature says “It even tolerates minor surface contaminants” it will not tolerate all out grease. Here is the suggestion assuming you have a relatively good fitting new caps:

1. Remove the hubs.
2. Disassemble to the point needed to clean out the area of the hub where the bearing cap sits (so the bearing and grease seals out, but races still in is ok).
3. Thoroughly clean the hub - with special attention to area of the mating of cap surface - with Brakleen or equivalent.
4. Tape off the Inside Diameter (ID) of the hub where the cap sits (to keep grease from getting on it)
5. Thoroughly repack the bearings by hand
6. Fill the area of the hub between the inner and outer races with grease from the ‘rear’ (where the grease seal goes) knowing the spindle will go thru there, so only pack it into the ID, i.e., leave it like a donut of grease (a big hole in the middle).
7. Install the rear bearing and seal. Run a bead of grease in the seal’s groove and fill in greese betwen the inner bearing and the seal.
8. Install hub, outer bearing, and such. Adjust and the normal things.
9. Wipe down area of tape to remove any grease that got there. May need to use a Q-tip.
10. Pull tape.
11. Install NEW caps using dimple effect (if they are slightly loose) and the Loctite.
12. Note: clean off the caps where engages the hub with Brakleen beforehand to remove any oils and no need to fill the cap with grease.
13. Enjoy trouble free trailering

When you need to remove the caps, it may be tough, i.e. need to destroy them.
Sorry for the long post > I think I was mistaken > its more of my 10 cents worth but hope this helps....

 

[ESGWheel]

@l008com
I just re-read your original post and saw that the caps were [always] “nice and tight”. So, apologies about the loose-fitting aspects of my post > when I read thru all the others about dimpling I got it in my mind they were ‘loose’. Regardless, the process to apply the Loctite should do the trick. Let us know how it goes when you take your next steps whatever they may be.

 

[l008com]

So i made my last post, and i drove to the river to put my boat it. Boated around for a bit, yanked it and drove home. I was feeling pretty good. Then yesterday, I was walking around my driveway doing something else unrelated and saw this:





I don't understand how they can be so snug fitting, then completely fall out in one short drive. I'm very tempted to solve this problem with a little 5200, luckily I don't have any right now.

Also I have never tried the "long" style. I've never even seen any like that before.
I don't think my problem is thermal expansion. The bearings were nice and smooth when i repacked them. And my drive was a low speed drive with lots of stop and go traffic lights. Perfect setup for keeping your hubs cool. Plus you can see from the pic, plenty of air space in there. Also I did not scrape any rust out of the inner diameters of these hubs.

This is super annoying!

 

[silverbul]

So i made my last post, and i drove to the river to put my boat it. Boated around for a bit, yanked it and drove home. I was feeling pretty good. Then yesterday, I was walking around my driveway doing something else unrelated and saw this:

View attachment 389927



I don't understand how they can be so snug fitting, then completely fall out in one short drive. I'm very tempted to solve this problem with a little 5200, luckily I don't have any right now.

Also I have never tried the "long" style. I've never even seen any like that before.

COUGH COUGH, rubber boots. jmo

 

[silverbul]

Albert Einstein, We do the same thing over and over—namely, roll the dice—and we correctly anticipate different results. Is it really insane to play dice? If so, it’s a very common form of madness!

 

[silverbul]

So i made my last post, and i drove to the river to put my boat it. Boated around for a bit, yanked it and drove home. I was feeling pretty good. Then yesterday, I was walking around my driveway doing something else unrelated and saw this:

View attachment 389927



I don't understand how they can be so snug fitting, then completely fall out in one short drive. I'm very tempted to solve this problem with a little 5200, luckily I don't have any right now.

Also I have never tried the "long" style. I've never even seen any like that before.
I don't think my problem is thermal expansion. The bearings were nice and smooth when i repacked them. And my drive was a low speed drive with lots of stop and go traffic lights. Perfect setup for keeping your hubs cool. Plus you can see from the pic, plenty of air space in there. Also I did not scrape any rust out of the inner diameters of these hubs.

This is super annoying!

I hate to see you stress over such a simple fix, I'm sure you have better things to do and move on from this. If you need any help, please let me know. just saying.

 

[l008com]

COUGH COUGH, rubber boots. jmo

Yeah I'm about ready to give them a try, I'm out of other options. But where do you get them? I don't see any stores that have the normal caps, having rubber boots in stock?

 

[silverbul]

Yeah I'm about ready to give them a try, I'm out of other options. But where do you get them? I don't see any stores that have the normal caps, having rubber boots in stock?

Amazon, Ebay.

 

[04fxdwgi25]

I looked on this iBoats site, but didn't see any

Here are some alternates:

Dust Caps and Oil Caps for Trailer Hubs and Drums

Trailer Parts Superstore sells trailer wheel hub grease caps and PVC oil caps at discount pricing. Easy to use online store with secure checkout.

www.easternmarine.com

https://www.etrailer.com/s.aspx?qry=dust+cap&furl=-pg-Trailer_Bearings_Races_Seals_Caps-sf-Caps

 

[richw46]

I have a '94 RangerTrail trailer. My dust caps were in rough shape from putting them on and taking them off to repack the bearings. I bought several sets of caps both locally and online but every one of them popped off. I have metal beauty caps on the wheels so they didn't fly off and I was able to put them back on each time. Still, no matter what I did they kept coming off. I finally called Ranger parts and they confirmed I had the right cap size. They said I should order the Ranger replacements and they guarantee they won't come off. They were expensive (of course) but they never came off again.

Is it possible to get replacements from your trailer manufacturer? You said it's an old trailer but maybe they still use the same caps. Another possibility is to contact Pacific Boat Trailers. They were able to find a replacement for my 29 year old rotors when one of them cracked. https://pacifictrailers.com/
Maybe you just need a better quality cap.

 

[l008com]

Here's what I did. I don't know if it's going to work, and I suspect most of you aren't going to like it. But I feel like I was out of options. I took my last unused cap, I got it started.... not fully seated, just "in" all the way around, but still sticking out by about 1/8 to 1/4 of an inch.

THEN I went inside and looked for some kind of silicon sealant but what I found instead was a tube of liquid nails. So I wiped all the grease that squeezed out as best I could, then filled that gap all the way around with liquid nail.

I tapped the cap in and of course, most of the stuff squeezed right out. Most but not all. Some has to have stayed between the cap in the hub. None would have fallen inside the hub so this won't effect the bearings at all. It will either hold the cap in place. Or fail just as easy as the bare cap. I'll find out next time I go for a boat ride which may be Friday evening. If this does work, I suspect I'm going to have to do the same thing to the other side next time it falls out.



Even if it doesn't work as an adhesive, it should still work as a filler, making it MUCH harder for the cap to "wiggle" out. And I'm not really concerned about getting ti off. Clearly these things are one time use so I'll just rip it to shreds if I have to. Plus the hubs are in great shape right now so I won't need to service them for a very long time. Given that I get about 2 boat rides in per year. But the state of the Medford Wellington Boat Ramp is a whole other side track.

 

[silverbul]

Here's what I did. I don't know if it's going to work, and I suspect most of you aren't going to like it. But I feel like I was out of options. I took my last unused cap, I got it started.... not fully seated, just "in" all the way around, but still sticking out by about 1/8 to 1/4 of an inch.

THEN I went inside and looked for some kind of silicon sealant but what I found instead was a tube of liquid nails. So I wiped all the grease that squeezed out as best I could, then filled that gap all the way around with liquid nail.

I tapped the cap in and of course, most of the stuff squeezed right out. Most but not all. Some has to have stayed between the cap in the hub. None would have fallen inside the hub so this won't effect the bearings at all. It will either hold the cap in place. Or fail just as easy as the bare cap. I'll find out next time I go for a boat ride which may be Friday evening. If this does work, I suspect I'm going to have to do the same thing to the other side next time it falls out.

View attachment 390195 View attachment 390196

Even if it doesn't work as an adhesive, it should still work as a filler, making it MUCH harder for the cap to "wiggle" out. And I'm not really concerned about getting ti off. Clearly these things are one time use so I'll just rip it to shreds if I have to. Plus the hubs are in great shape right now so I won't need to service them for a very long time. Given that I get about 2 boat rides in per year. But the state of the Medford Wellington Boat Ramp is a whole other side track.

How much have you spent on caps and adhesive so far?

 

[l008com]

I haven't spent anything on adhesive. On caps, since this problem started I've probably gone through 8 caps? The caps are super cheap but the issue is more, they fall off right away so I end up putting my exposed hubs underwater so if I just keep throwing cheap caps on, I'm going to ruin my bearings.

 

[04fxdwgi25]

THEN I went inside and looked for some kind of silicon sealant but what I found instead was a tube of liquid nails. So I wiped all the grease that squeezed out as best I could, then filled that gap all the way around with liquid nail.

If grease is squeezing out when cap is installed, I would suspect the bearing / cap space is over packed with grease. Maybe when they heat up, the pressure increase pushed the cap off.

 

[silverbul]

“Insanity is doing the same thing over and over and expecting different results.

 

[JimS123]

Alls I know is what I see in the posted pictures. Looks to me like you have a bunch of old rusted crap.

Replace the hubs, PROPERLY grease them and put on new hubs that ARE OF THE PROPER DIAMETER.

I have owned a dozen or so trailers over the past 55 years and never once had a cap fly off.