Crankshaft Diameter

[alexanderfoti]

Hi all

I just purchased a taperlock bushing for use with my new 186FAG, but it turns out that my crank is 26mm rather than 25 ... Grr, it also appears as though there isnt a 1008 - 26mm bush rather only a 1008-25.

Any ideas?

[forhire]

Can you have the bushing bored to diameter on a lathe?

[pietenpol2002]

I had the same problem. And there are no 26mm bushes to be found in captivity. I simply took mine out to 26mm with a brake cylinder hone.

[alexanderfoti]

Interesting, whats the best way to hone it with the brake cylinder hone without going too far, its only 1 mm!

[pietenpol2002]

Because you're only honing, it takes forever. Little concern about going too far. You'll see when/if you do it. Just check it regularly against the shaft.

[alexanderfoti]

Perfect!

Assuming my Crank is tapered like:

http://i51.tinypic.com/1262tkl.jpg

Which way round would the taperlock go on , as the taperlock is tapered as well (obv ) or does it not matter?

[pietenpol2002]

While there are taperlocks built specifically for tapered shafts, I suspect yours is for a straight shaft. As such, it mounts on the 1 1/2" of straight shaft available before the taper of the cranks begins. Your bushing has 2 opposing tapers that are drawn or forced past one another to simultaneously exert forces against the outer shell of the bush and the OD of the crank. It's typically mounted with the tightening bolts to the outside. One should start with the bushing positioned tight against the shoulder of the crank. But, be aware that as you tighten, the bushing will generally move outboard relative to the shoulder. 3 bolts are usually used to draw the taper tight and then repositioned in the 3 other holes to force the tapers apart when dismounting the bushing.
Does this description fit with what you have?

[alexanderfoti]

That sounds a bout right

I see how it works now, thanks for explaning

I am having trouble honing though, I have been through 2 sets of honing stones and I am only out to 25.22mm (measuring with digital calipers!)

Any other ideas, or anything that can speed the process up?

[pietenpol2002]

I apologize if I led you astray on the honing project. In my application I started with a considerably larger keyless bush (can't now remember why. Might have had it on the shelf). I spoke with the manufacturer who noted that one could utilize a standard piece of bushing stock between the keyless bush and the crank. as long as you slit it to allow it to be squeezed by the outer bush. I thus went with a piece of 1" ID bushing stock that I honed out to 26 mm. The bushing stock may well have been a bit softer than the keyless bush and thus easier to hone. I do apologize for not disclosing this in my earlier post. I fear I hadn't considered the prospect of harder material.
Any chance of a more aggressive stone?

[alexanderfoti]

No worries, I think due to the reliative hardness of the metal that me being able to hone it out to 26mm may prevent me from doing this.

I need to find a metal worker that will be able to bore it out to 26mm using a lathe etc.

I would do it if anybody knows another method?

Even the custom taperlock shop say that cant make one.

[alexanderfoti]

right, so many places say they cant bore this out becuase its hardened steel. Am I going crazy or is this a lot harder than it should be

All I need is to make this:

http://www.bearingboys.co.uk/31-19_Roll ... p-338735-e

Fit onto the taper lock bush and onto my crankshaft:

http://i51.tinypic.com/1262tkl.jpg

Any ideas?

[forhire]

right, so many places say they cant bore this out because its hardened steel. Am I going crazy or is this a lot harder than it should be
Any ideas?

To take off 1mm with a hone is a LOT of material... as you discovered. I suspect the bushing is case hardened. Any shop with a tool post grinder should be able to do this. I'd check with a grind shop... they are good at jobs that are tough to turn. What about pulling the crank and having it ground?

[alexanderfoti]

Yeah, took me about 40 minutes of "honing" to do 0.2mm!

The problem is I dont know of any shops, in west london, that would be able to do this, and google is killing me, any suggestions where I can just get it posted:)

I was thinking of getting the crank re-ground but I dont fancy taking the whole engine apart and buying new gaskets etc if it doesnt need to be done.

Cheers for your help btw

[alexanderfoti]

All sorted , i finally found somebody local to me who managed to borr it out. now to get the clutch removedq!