Shimano freehub service

[slowster]

I have just followed Brucey's instructions and tips in this thread and elsewhere (viewtopic.php?p=1564606#p1564606) to set up the rear hubs and freehubs on two new wheels, having first run them them in for a few hundred miles as Brucey suggested.

The first hub was quite easy, and I found the hub vice tool (made using the QR skewer, some axle spacers and a spare hub cone, but no bench vice) made adjusting the hub much more straightforward than my usual approach.

The second hub however had noticeable play in the freehub (holding the 32 tooth sprocket on the cassette I could feel about 1mm of movement). In anticpation of encountering this problem at some point, I had already bought a freehub body tool from Ebay like the one in this link - https://www.ebay.co.uk/itm/133710045574?. The bolt supplied with the tool was too short for my 135mm hub, and probably would be too short even for a 130mm hub. I instead used the QR skewer to clamp the tool into the freehub outer race/cone and a large penny washer between the QR lever body and the hub on the non-drive side.

Although I noted Brucey's instruction to loosen the cone initially only just slightly, and only to completely undo it and remove it after turning the wheel so that it was horizontal, in order to leave the freehubs outer 25 ball bearings in place, I failed to appreciate that I needed to keep the outer main part of the freehub body in place to prevent the inner 25 ball bearings from escaping. Lesson learned: don't lift or tilt the outer main part of the freehub body even slightly once the cone is loosened more than a turn or so.

There were three shims in my hub, and I removed just the topmost shim to eliminate the play. I initially thought that left the freehub fractionally less free running than perfect, and to try to compensate for that when I reassembled the freehub I experimented with slightly varying the tightness of the cone using trial and error. However, I was probably imagining it, because I have since compared the freehub with one in a brand new wheel built with the same hub, and my adjusted freehub is if anything more free running (the gear oil with which I lubricated the freehub after re-assembly will have helped).

This was a new task I was not looking forward to tackling, and I would not have even considered attempting it were it not for Brucey's detailed and thorough instructions. But like others who have followed his instructions, I found it a straightforward task, and one which I would not hesitate to do again.

[TheBomber]

like others who have followed his instructions, I found it a straightforward task, and one which I would not hesitate to do again.

I would concur - a little fiddly but if you are used to working on all the other bearings on your bike, and you are not in a hurry, then they are perfectly serviceable. The trickiest one I’ve done was an XT with an oversized alloy axle as there was even less room for the bearings. With that one the bearings on the outer race would ride up on top of each other as the cone was tightened down. Resolved by holding the cone and the outer part of the FH body together and tightening the FH innards into the cone.

Were you working on FH bodies with 2 or 4 pawls? The 4 pawl models seem to be more prone to slipping issues if there is any play in them. That XT one was new but started slipping from the second ride. However, with the Brucey shim treatment it has been fine since.

[colin54]

Good to see Brucey still receiving comments of gratitude for all his efforts on all our behalves, nice one.

[slowster]

Were you working on FH bodies with 2 or 4 pawls? The 4 pawl models seem to be more prone to slipping issues if there is any play in them. That XT one was new but started slipping from the second ride. However, with the Brucey shim treatment it has been fine since.

A two pawl freehub: FH-M756A (XT disc) - the same hub with play in the freehub as mentioned in this post viewtopic.php?p=1443226#p1443226.

I simply followed all Brucey's instructions for setting up a Shimano hub, with the exception of drilling the hub shell for a lubrication port because of 531colin's comments here: viewtopic.php?p=1424824#p1424824. I suspect a lubrication port in the hubshell works best with those freehubs that don't have a seal (and assuming semi-fluid grease is used), such as 7 speed freehubs.

[rogerzilla]

Taking apart Shimano BMX freewheels is probably worse, except you don't have to deal with the RH axle cone. 96 loose balls, and you need the thinnest possible grease that will just hold them in place for reassembly, so as not to run the risk of sticking pawls. I used SA IGH grease.