Thread butchered!!!

[canolman]

Discovered this today, suspect the nut ran out of thread before tightening? Should there be a slim washer? Cut a 14mm fine thread and nut to suit?



No sign of loctite!!:furious::furious:

 

[bushmechanic]

sounds like a good idea, thats what i would do

I have seen a repair pic where the whole end was sheared off or cut off

thread was tapped or machined internally and a stub made with a new thread and seal landing on the stub

 

[Taffy]

i have a company that change the end of the crank to a bolt with a hole through the middle. if this suits you then send me the crank and I'll get it done. unfortunately it is £211 postage 3 ways done.

Taffy

 

[canolman]

Cheers boys,
Just been speaking to a lad in town who's pretty sure he can do it, may even do it today! We may be back on track soon!

 

[canolman]

Makes you proud to be British!! Bloke up the road, in a shed, 2 hours cut thread and made nut!
What Loctite would you recommend?
Would you in any circumstances drill cog and nut and lockwire together?
Been told it's common for the nut to fall off!! Really??

 

[bushmechanic]

looks good

this is a JBS idea grind a flat on the gear, make the nut 1mm thinner

I run mine like that but really don't think its necessary, just degrease the threads with a water based degreaser 262 or 263 on the threads and 609 on the gear/shaft

if you don't heat the nut with a propane torch on disassembly the loctite can strip the nut... its that good.

 

[canolman]

Decided to lockwire this nut because after a couple of race meetings it's not as tight as I'd like! Discovered this when I was changing the pump seals.
Pretty sure the nut was tightened with a rattle gun last time but I'd prefer it was done with an old fashioned torque wrench, can I tighten it with a stop bolt in the crank or do I need to buy a cog tool?
Don't need this coming undone again! Loctite 2701 and plenty of heat to get it off again?
Many thanks.

 

[bushmechanic]

cog tool, sprocket spanner or an appropriately shaped bit of aluminum is better

I did a test once; if the locking bolt is on the ignition side the crank twists on the big end pin when you tighten the drive pinion.

the engine im building now has a second hand drive pinion. the bloke i bought it off said it came loose once.. I noticed the fit of the pinion onto the crank (of this one) is quite loose

 

[canolman]

Cheers Bush,
Half a hole drilled so far and we've had to order more tungsten drill bits!!
What would you torque the nut up to seeing as I had to cut a smaller thread?:unsure:
Diolch in advance.

 

[bushmechanic]

whats the diameter and pitch?

if you work out the % difference in area compared to the M16x1 that will give an idea

a spherical diamond coated burr will be the easiest way to drill the gear