I am going to be changing the bearings in a dt swiss 240 rear hub so I have ordered the ring nut removal tool from an ebay seller for £31.

I can buy the special dt swiss grease, (see here:https://www.bike-components.de/en/Dtswiss/Spezialfett-20-g-p7831/ ) for the ratchet but it seems expensive for only 20g of grease. Does anyone know of a cheaper equivalent grease or what type of grease this stuff is? I don’t just want to use multi purpose grease as this may affect the operation of the ratchet.

I was also wondering if the seal installation tool is really necessary? (see [/url] page 4 item 3 Seal installation tool (Ø15/36x10mm) HXTXXX00N5026S) Can I get away with just pressing this in with something else?

Cheers

To be honest 20g of grease will last a very long time as you should use a smear only each time.

Having said that, my LBS recommended I use Finish Line Ceramic Grease as a reasonable alternative. I have used this for the past six years with no issues. Just be very sparing in application.

The seal tool is useful as the seals are notoriously sensitive to damage which leads to drag or even locking up of the freehub.

Again, it is possible to use a flat disc of exactly the right diameter that presses the outside metal ring of the seal. I turned one up on a lathe and I have installed seals without problems.

as an owner of these said hubs, can i ask how often you plan on servicing them? Is it worth the kit? My thought was to not bother and get them serviced approx every 3 -5 years in a shop….! may be optimistic!

In my experience, taking the freehub off and cleaning/greasing the ratchets every 3 or 4 months is worthwhile and is I think what is recommended by DT Swiss. This can be done in five minutes once the cassette is removed without any specialised tools.

I have two sets of 240 hubs, and have never had to change the axle bearings on either, I have changed the bearings in the freehub on one set. A friend has some Spline wheels with the same internals and I have changed the bearings on his rear wheel. I made my own set of tools based on the dimensions in the handbooks and bought a ring nut tool. Even with the correct tool I managed to damage a seal because I didn’t line it up carefully, but I won’t do that again, and as stated above, I have sucessfully fitted ones since

If you don’t have access to a lathe, for the likely frequency of changing the bearings it would be more economic to get an LBS to do it rather than buy the official tool set from DT Swiss. You can get non-original tool sets on ebay for about £50
Edit: i have just checked and the seller of the other tool sets doesn’t seem to be posting stock any more

Thanks for the info guys. The finish line grease on CRC is £8.99 for 60g so I may as well get that.

I have already ordered the ring nut tool for the rear hub so I am going to do it myself. The labour cost is £40 an hour at the local shop so I usually find if I use a tool a few times it will at least cover the labour cost. I might get a seal tool made up on a lathe if I can’t find anything suitable.

Jim,does the seal need replacing when you take it off to change the axle bearing or can it usually be reused?

Howsyourdad1: Occasionally I have ridden through deep streams and fords in the past and this is what must have killed the bearings after 2.5 years use at about an average of 1 ride per week., so I will be keeping them as dry as possible from now on. Hopefully they will last longer this time and I think I will always keep the hubs so it is worth having the tools and grease for the next time they need servicing.

I got skf steel bearings and they were £11 each so that is another reason to try and keep them dry! If I had the got the stainless steel skf bearings they were about £25 each!

I am going to be inspecting and cleaning the freehub and ratchets much more often, as you say it is easy to take off the freehub.

I use buzzy’s slick honey for the grease, but it’s not especially cheap either, I just already own it for seatposts. Works very well though.

If you’re doing a full service and replacing all bearings, then the freehub with no bearings in makes a perfect seal fitting tool. But I’ve succesfully fitted one with a big socket, it didn’t seem to suffer from it at all.

(re specialist tools; it’s easy to fit bearings with sockets, as long as you’re careful and at least a little bit handy. It’ll take a long time with DT240s to pay off the tool set compared to getting a pro to do it, if you think how long the current set of bearings have lasted you- most likely some bastard at Trek will invent a new hub standard before it pays itself off 😉 )

Are you sure the inner bearing- the one behind the seal and ring- needs changed? It’s extremely well protected, I generally find it needs done maybe 1/3d as often as the brakeside outside bearing so usually if you think “these need serviced” it’ll be the less well shielded bearings. I’ve only ever had to do the centremost bearing a couple of times. Some hubs, it makes sense to do the whole set at a time but not for me, with these.

Be warned though, it can be a bastard of a job to remove the ratchet ring.

On Friday I managed to do the front hub quite easily and I used a 1/2″ drive 19mm socket which was just the right size to push on the bearing outer race, so I should manage to do the same on the rear hub. Hopefully I will have a socket the right size to push on the seal during fitting.

When I turn the rear axle it feels quite rough now but until I take the non drive side bearing out I won’t know for sure how bad the drive side axle bearing is.

Be warned though, it can be a bastard of a job to remove the ratchet ring.

^ Is this because the thread isn’t lubricated and the nut seizes on? There is quite a big moment arm if I am turning it at the tyre so it should come off…

I think it’s mostly because they’re too reliable- so the ring’s got plenty of time to stick. I’ve had limited success with the “clamp it in a vice and twist” thing, so I figured out a way to attach my 30 inch breaker bar to the tool. That creates a different problem, of holding the wheel still, but it’s doable.

The seal is often reusable I believe. I had a spare handy anyway. Just in case.

It does take a remarkable force to loosen the ring nut if it hasn’t been moved for a while. I used the tool in a vice.

Contrary to what at least one online guide suggests, I would advise taking the axle out by knocking the NDS bearing out before using the ring nut tool. It would be very easy to bend the axle if it was still in place as you grunt and swear trying to break the nut out. I found a constant force held for a discouragingly long time gets the job done better than trying to jerk at it

The seal gets lifted out painlessly when the ring comes out so if it was good before it should be good after. (except the time that no force on earth could move the ring, so I brulee’d it to loosen it up, the seals did not appreciate.)

Things I have learned whilst servicing my DT 240s.Bearings are not friends with Welsh rivers.
The correct tools are required. There is no substitute for the ratchet ring remover. (but see below)
Be warned though, it can be a bastard of a job to remove the ratchet ring.
A long bar zipped tied to the rim gives enough leverage to snap a vice.
An old piece of polypipe is just right to fit the seal, or an appropriately sized socket. It is possible to fabricate a lock ring remover by welding a ratchet ring to a blooming big bolt.

I thought about that but no chance would my shitty welds stand up to that 😆 I was just going to stick it to the side of a big bit of bar and make its own lever.

By special tools, I meant the bearing things- the posh sockets.