how do I get this off?

[drlapo]

I'm working on an old BSA single engine and cannot get the oil pump drive gear off
it's slip fit on the crankshaft with a woodruff key, I got the key out and can spin the gear on the shaft with a brass drift  but it won't slide off.
it's a worm gear and it's been on that shaft for 45 years
I put  vise grips on it, cushioned with a piece of inner tube, and then tapped  the  vise grips with  a small hammer; no go
next I put some heat to it with a propane torch= nope
I can't get behind it and there is no room for a gear puller
any suggestions?

[drlapo]

no holes, no flange, no way to get behind it or grip it with a puller

[rodekyll]

If you can sacrifice the gear it would give you more options.  Do you have access to a new gear?

[drlapo]

I have 3 engines trying to make one good one
1968-1970
250 single
the manual says to slide the gear off; it don't slide
I'd rather not destroy it

[rodekyll]

That's what I'm thinking.  Some swarf between the gear and shaft is binding it in the off direction.  Can you get a wire hook up the keyway and "slide-hammer" it off?

[rodekyll]

It's been a long time since I worked the parts counter for BSA.  IIRC, the pump drive gear is a brass/brass alloy part while the shaft is steel.  Very easy to gall or bind brass to steel.

 . . . and I used to think the piston pump/dry sump was goofy . . .

[krglorioso]

Correct David . Of course , the Triumph style plunger pumps were an odd design , but these are English engineers
(Edward Turner , Val Page) we are talking about . Let's see , make the pistons go up and down together , and who needs a center main bearing ? :D

  Dusty

The 1950s Matchless twins had a center main bearing, I believe.  I don't know that they had any better reliability than the Triumph/BSA/Norton twins did without the center bearing. 

Norton had a clever response when their flat roller main bearings went sour on the Commandos due to crank flexing; They decided the crankshaft was going to flex anyway, so fitted FAG elliptical roller bearings to the mainshafts in late 1972, I believe.  These allowed crank flexing without the predictable damage flat rollers suffered.  The Brit engineers were much better at fitting add-ons to cure initial design problems, than they were at changing the original design.  Witness the isolastic drive line mounts on the Commandos to mask the irreparable engine vibrations.  My 1974 Commando 850 Interstate has both modifications as did my (sold) 1973 and they really worked quite well.

Ralph

[Sasquatch Jim]

  With an eyedropper wick in a drop of nitroglycerin under the part.  Wire it to the spark plug lead and place a pillow to catch the part.
  Fire the spark plug.

[racasey]

Have you removed the oil pump (2 hex head cap screws) and pulled the oil pump drive shaft (down) away from the worm on the crank shaft?

Ciao,
Dick Casey

[drlapo]

the pump is out, the cam drive gear is off, the nut at the end of the crankshaft is off
I may need to destroy the gear, i have others and i want to reuse the crankcases but not the crankshaft
I may need to split the cases and put the right side in the oven, heat it up, remove the right side main bearing with the cranskshaft and the offending gear

[Tobit]

Picture?

[drlapo]

no digital camera= no pics

[pressureangle]

Does the gear use only an end of the woodruff key? Some stuff I've seen drives 2 gears with 1 key. If so, perhaps a light file across the key slot edges would help.

[Mike Tashjian]

If you have other parts to compare, that would be the first thing I would do.  I have a feeling a bit of clearance has raised kind of a burr that you will have to file down.  You could try a small file to concentrate right next to the gear or generic sandpaper wrapped around the shaft. Drilling and tapping a couple of holes into the gear might give you the chance to use a puller if that is possible.  I try to resist destroying any part until there is no other option.    Mike

[drlapo]

it's off
lots  of heat from a  propane torch and I used a paint can opener to just hook the back of the thrust washer.  it moved enough to then get a thin gear puller behind the gear, i had to hold it closed and with a bit of patience it came off

now I have to remove the same gear from two other engines in my search for enough good parts to make one good engine

thanks for all the suggestions

[oldbike54]

Kool  ;-T

  Dusty

[rodekyll]

So, did you discover what the hang-up was?