Crank Pulley/Balancer 3B problems

[tasnolan]

Can anyone give me some advice regarding replacing the crank pulley on a 3B. My pulley came free and has oblongated the pulley sleeve and rounded off the locating lug from the crank. I have attached a pic of both.

Now I have another pulley/balancer to replace it with, but ...

1 Should I be concerned that the locating lug on the crankshaft has rounded away?
2 Does the pulley need to be balanced before putting onto the engine?
3 Anything else I should be concerned with prior to attempting this?

Thanks for your help in advance

 

[lostmarbles]

Can anyone give me some advice regarding replacing the crank pulley on a 3B. My pulley came free and has oblongated the pulley sleeve and rounded off the locating lug from the crank. I have attached a pic of both.

Now I have another pulley/balancer to replace it with, but ...

1 Should I be concerned that the locating lug on the crankshaft has rounded away?
2 Does the pulley need to be balanced before putting onto the engine?
3 Anything else I should be concerned with prior to attempting this?

Thanks for your help in advance

Yes you should be concerned about all of this.



That key (which I think you're calling a "locating lug") is called a "woodruff key". And if it has been being bashed/hammered from side to side ... and has thus widened the recess that it sits in (in your crankshaft) .... then the correct/ideal solution is to replace your crankshaft (which will no doubt have its circumference worn where the pulley has been rocking too) as well as replacing the pulley/balancer.

But due to the "extreme" nature (and cost) of this "correct repair" .... if it was me I'd fabricate a special Woodruff key that both fits your new pulley AND fits the worn recess (as best as possible). ......... But expect making this to be a timeconsuming chore involving lots of filing/sanding and I think you'd have to be very careful not to drop your "special key" inside the timing cover during the many trial fitments. (Perhaps you could start with a new key onto which you've added some small welds?)

Then I'd thoroughly clean all mating surfaces with Loctite Cleaner before "gluing" the new pulley and woodruff key to the crankshaft with Loctite Quickmetal.

Done properly ...I wouldn't expect it to come loose again. (In fact, I think you'd need oxy-acetylene heat and to destroy the pulley to get it off again.)

Because of the crank damage .... I'd ignore any "balancing aspect" to this - provided the new pulley looks like it seats properly/concentrically ..........(asscertained by trial-fitting prior to Loctiting).

 

[tasnolan]

Champion, thanks for your help. I have removed the key and the oil seal for replacement. Will do some trial fitting and backyard mechanic specials to hopefully get something to work.