Dust cap removal on Shimano hub
 

It appears that some water got into my rear hub (probably from washing) and it required a breakdown and re-lube. This was the first time I've done it on this bike and I have 2 questions...

For the record it is a 2013 Trek FX7.4.

1. It appears that there was no outer rubber dust seal on the non-drive side of the rear axle. Where can I get one in the USA, online or LBS? I'm not sure if it was supposed to come with one or not. I bought the bike new and have not touched the axle until last weekend.

2. On the same side there was a metal dust cap/retainer pressed into the hub. How do I remove that retainer (is it meant to be removed?)

Sorry I don't have pics and I will provide them if requested. This is an entry level Shimano hub.

Many hubs don't have rubber dust seals. So, your hub might not be designed for one.

Regarding the metal dust cap, it is probably removable with careful application of a flathead screwdriver. But be very careful, because they are easily bent rendering them deformed and basically useless. A picture of the hub will help us here.

Sounds like nothing is wrong, but you just need a simple repack of the hub. This is a regular maintenance item (that is neglected by many people.)

According to Trek, it's a Shimano RM-30 hub you have.

Don't remove the dust cap. Just remove the left side lock nut, any spacers or washers, cone, and then the axle and right side cone will come out. Catch all the bearings on a shop rag, and then clean the inside of the hub. Put in new bearings with plenty of grease then reassemble and adjust. It'll last for years if you do this every year or two and you keep water out.

More detail: http://www.parktool.com/blog/repair-...and-adjustment

Your hub probably didn't come with a rubber seal. Don't worry about it.

As Jeff Wills recommended, it's not necessary to remove the dust cap to clean the bearing cups. You can reach under it with the tip of a rag to clean out the old grease. However, as Fastjake said, they are removable by working a flat blade screwdriver gently around the inner hole and prying it out evenly. I've even reshaped distorted dustcovers on a flat surface using a plastic hammer and punch.

You can also reshape using an appropriate sized socket as an anvil......

+1. Dustcap removal and reinstallation was one of those things that really vexed me before I realized I didn't need to do it. ;)

Don't do it. I bent the dustcap the first time I tried.
To clean behind the cap, wipe out the grease, slosh a little solvent around, stuff some rag in and rotate. After drying, over-fill with grease till it extrudes through the gap as you spin the finished wheel. The fully packed bearings have no room for water and dirt in get in. My unsealed bearings remain clean after a wet winter of riding.
The usual seal on Shimano hubs is a rubber washer style that slots onto the cone. You need to correct size cone to fit the hub shell. If you use the wrong size you have to remove the seal.
The MTB style external rubber cap is additional to the cone seal.

Good advice. I also "overfill" all cup-and-cone hub bearings and the excess grease extrudes out for the first couple of rides and requires wiping off the exteriors a few times. It then acts as an additional seal and does a good job of protecting the bearings from dirt and water. Better to have grease leak out then crud leak in.

If you're careful it can be removed with minimal deformation. You can then clean the hub thoroughly and repack the bearings. Its a very simple task to reshape and reinstall the seal.

One good reason to remove the dust cap
 

This is an old thread, but in any case....

There is in fact one situation when you do need to remove the dust cap -- to move it to another freehub body. The case here is a Shimano Deore DX hub that I'm switching from 7 to 8 speed. All good, but the NOS freehub body (FH-M525-A) doesn't come with a dust cap. They're semi-specific to the cones/seals/etc., that are with the axle, so that makes sense. While the dust caps for some lower-end and/or newer Shimano hubs are plastic and can be popped out with relative ease, older Deore ones are steel, and appear to be threaded into the inside of the freehub body. I tested the lever routine on a junk hub and utterly destroyed the steel dust cap -- it *really* didn't want to come out.

So how to remove such a dust cap for transfer to another freehub without damaging or destroying it? My only thought is some kind of reverse pliers, that spring outward to grab the inside of the dust cap, which could then be rotated out. No success finding such pliers such. Alternately, I can try to create a jig that will reach inside the dust cap on two opposite sides, and then pinch above/below to grab it. (Mentally it's clear how it would work, but I'm describing it poorly.) Basically, you have to be able to get a grip on something that has no flats in order to spin it out of the freehub body. Perhaps even a matching pair of tiny pliers/visegrips poking out on opposite sides, and crossed so you could grip and turn. Hmmm, still thinking...

Any suggestions welcome.

L.

Bitd
 

:50: to remove the dust cap on antique (but new when I bought them) Campagnolo Freewheel hubs , ... procedure

was ... when axle was removed, already ,... lay a cone wrench on the face of the dust cover

the cone wrench spread out the force.. then, using the cone wrench as the fulcrum , ..

use the tip of a flat bladed screwdriver to pry out the opposite side..





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Thanks for the reply. Alas, prying won't work in this case -- the dust cap appears to be threaded into the freehub, and thus must be rotated out so as not to destroy it. The two-plyer routine might work, need to get the size right...

pin face snap ring pliers perhaps, ?

but I'd join the leave them there and service the bearing balls, races behind it group, since I'm not there..

and, so, I'm not clear on why you feel a need to remove them..



good luck...





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Thanks for the reply. I tried snap-ring plyers, they don't have enough grip on the dust-cap's inside face (plus I don't want to damage it, obvously). The reason for needing to extract it is that I'm switching the freehub, from 7 to 8 speed. The replacement freehub is NOS, and doesn't come with a dust cap. Shimano's seeming assumption was that you'd buy one to go with your specific set of cone bearings/seals, etc., and install it. But I don't have a replacement one, I only have the dust seal in the to-be-removed 7-speed freehub body. So I've got to get it out without damaging it. Alas, Sheldon Brown is no longer with us, would love to ask him.

dust cap on the driver? or seller shorted you with incomplete hub missing that part.. ?

There is no rubber dust seal on that hub. You must be careful when washing your bike.
https://si.shimano.com/pdfs/ev/EV-FH-RM30-7S-2389C.pdf

A powerful earth magnet & a dentist pick might work.

Installation is pretty easy, since it's designed for a one-way trip into the freehub. Before riding off, you'll want to test-install an axle and be ready to use pliers or similar tools to tweak the dustcap back into being concentric. :)

It pushed right back in, and seems to be happy. Was unable to test ride. So, will report back catastrophic failure.

No dust cap on 8 speed cassette hub body
 

I ran into the same problem and solved it by buying a Y3CR98070 Shimano Tiagra FH-4500 Freehub Body (w/ Washer and Seal). It comes with the dust cap and washer the FH-M525-A Freehub body did not, and only cost $5 more.

Been there, done that!