crankshaft to rusty?

[ade]

Today I turn my attention to the Crankshaft. I intend on splitting it and replacing the big end bearing but note the manual states a fly press must be used. Has anyone done this job and have any tips? I assume one crank bearing is better with the roller bearing but the other bearing is very expensive at around £80, is it cheaper anywhere else? Also don't they need to be polished? is this to rusty.

[BultacoBen]

Also don't they need to be polished? is this to rusty.

Hi Ade,

did you mean to include a photo? There's none attached...

Ben

[ade]

pic of the crankshaft

[alanengineer]

you need a flypress to take the thing apart, dont even think about using a hammer or prizing the the flywheel away from each other.

Also, you will need some way of aligning the flywheels back together as you assemble them. So, its not really a diy job, but its not difficult if you have the tools

[Mick D]

Hi

Splitting and re-assembling a crankshaft is not something I'd attempt without the full suite of tooling and instructions. In addition to the fly press and splitting tool you will need a method to hold the assembly between centres, (sizeable lathe), and means to determine the run out, (dial test indicator and clamps). The torque on the bearing journal nuts is also very high, holding the assembly whilst applying this sort of torque will be 'challenging'.

Rust? - Depends on how much and where, none whatsoever on the big end journal or the shoulders of the flywheels in this area, and none on the bearing surface which mates with the timing side bush. Elsewhere light surface rust can be tolerated, remove it before re-assembly.

Regards Mick

[Rob Harknett]

pic of the crankshaft

No picture perhaps you are missing some thing. First the pic must be below a certain size. step 1. bottom left click upload attachment, click browse, select a picture on your computer, click open, you will then see the file name appear to the left of browse, click add the file, wait a while for it to load up. You may then need to scroll down a bit, to see Place in line. Position the little blinking " l " to a line below your text, then click place in line

[Eamonn]

No picture perhaps you are missing some thing.

Only club members are permitted to load pictures into the forum - non-members can load pictures into another picture store (such as Dropbox, Flickr, Photobucket, etc) and put a link into their posting.

[ade]

I only wanted to change the big end bearings out of good practise as the engine has been apart many years. and there appears to me to be to much movement in it when I rock the crankshaft back and forwards and up and down. I will have a closer inspection tonight and sort out my pics as they are to big to post. I wouldn't attempt to split the crank myself, I have a friend with a decent workshop. I assume there is a little tolerence for movement but cannot see what that might be in the manual I have.

[alanengineer]

up and down their should be no movement, side to side their should be some movement (dont know what is permitted)