[Closed] XT Hollowtech II crank question - widget thingeemabob ID

Is it the pre-load nut that screws into the axle?

http://www.chainreactioncycles.com/Models.aspx?ModelID=5095

nope... it's the bit that sits in the crankarm and slides/slots over the splines on the BB spindle, rubbish description I know!

If it's the flat plastic spacer that fits in the gap between the bolts, I wouldn't worry about it.

I've got 3 XT chainsets on the go and none of them still have this part.

The spacer between the crank arm bolts?
Why bother,I've been running mine for years without one fitted.

which bit.

Thanks for the schematic robhughes, I googled but couldn't find it.

ah, crap... doesn't look like it's a replaceable part?? it's not the spacer bit (part 4 on the diagram), it's the splines in the crank arm that slot onto the BB spindle. It looks like this is a plastic insert into the crank arm, I assumed this was replaceable...

I ask as I've had the cranks polished and clear powder coated and apparently this bit has fallen out? Though haven't seen them yet, so maybe worrying over naught...

no probs.just type(shimanotechdocs)all the pdf,s are there.

Eh?

The splines are [i]machined[/i] into the crank arm.

stu thats what i thought????
psychle which part of the crank are you looking at.

the round circle/hole in the crank arm... from memory (I don't have the arm in front of me), there's a 'black ring' in this that is the splines, I assumed this is an insert? maybe it is machined into the arm? guess I'll wait till I get them back, might be making a mountain out of nothing 😳

cheers chaps 🙂

PS: anyone got an arm they can pop an image up of the area I'm talking about?

No - the splines are the toothed grooves on the axle and crankarm which mate together when you slide the latter over the former. The twin bolts tighten them together to remove play and create the crankarm interface.

On both parts they are machined onto/into metal surfaces.

There are NO parts to the chainset other than those you see in the techdocs.

I think there is a rubber/plastic part clicked in to the arm, to space it from the bottom bracket, but any old plastic washer will do that, I hope?!

On both parts they are machined onto/into metal surfaces.

phew, coolio, thanks for clarifying 🙂

PS: anyone got an arm they can pop an image up of the area I'm talking about?

EDIT: no matter, clarified by stuartie_c.

Isn't there a thin rubber 'o' ring on the inside edge of the mating face? Seem to think there is, But too cold to go outside to have a look!

Isn't there a thin rubber 'o' ring on the inside edge of the mating face?

Shouldn't have edited the last one!! Do you mean this...

[img] [/img]

Yes, there is a small rubber o-ring.

On the LX HTII cranks I have it's got a lip on it and clicks onto the arm, but on the XTR cranks I have it's an easily lost, very thin o-ring.

Either would be easily replaced by any narrow o-ring that you could by from a Tool-Station type shop.

can anyone tell me the size of the o-ring? ^^^ need one 🙂
also is it that impotant?

can anyone tell me the size of the o-ring?

It's not an o-ring; it's actually a thin metal washer with a rubber coating - rounded on the upper side, flat on the underside. The aperture it sits in has an ID of 24mm and on OD of 27.6mm.

I suppose it could be replaced with an o-ring. Something like 1/8th of an inch with a suitable ID.

It's purpose appears to be to mate with the seal of the BB cup and prevent the ingress of water/dirt into the bearings and around the LH crankarm splines.

psychle/ walla24
On the inside of the crank arm where the pedal screws in there is a part number fcm --- if you can tell me this number i should be able to tell you the part number for the part you need

littledean- numbers are:
"Shimano EC 175 FC-M800/M805" (they are saint cranks)

realised i do need the washer after my seals got ripped to shreds by the crank (frozen together!)

cheers