Gearbox bush removal

As I dismantled the gearbox of a 1974 Commando I'm restoring, I "baked" the main case in the oven for removal of bearings and bushes. The bearings dropped out easily enough (well one needed some gentle persuasion) and I was foolish enough to attempt removal of the 2 bushes that house the camplate spindle and the gear selector fork. They didn't budge. Not hot enough, one assumes, so used a propane torch followed by use of a drift - neither budges. Next, called a friend with a hotter torch - no dice. We've tried different drifts and a makeshift extractor using a threaded bolt but, you guessed it, without success.

Unfortunately, I can't just leave them in as my bullying has left them scored. I was going to try screwing in a tap from the inside, next, and whacking on that from the outside but, before doing that, I thought I'd ask for some expert help. Anyone with any ideas?

TIA,

Paul.

Careful cut relief grooves in bushes, &/or drill to crumple thinness, then repeat the push pull methods after hi heat very locally on inside bush, then wait 30 sec for heat to flow out bush into case to shrink bush and swell its bore in better ratio than everything hot. A sprtiz of carb spray in bush might shrink a tad more to relieve.
The power of list mind focused over night on a trouble spot has worked miracles for me, hope same with you.

Hi Paul
I used a nut and bolt with a washer on the inside just smaller than the hole in the casing and a bit of pipe on the outside and drew the bush out into the pipe.

KEV-C said:

Hi Paul
I used a nut and bolt with a washer on the inside just smaller than the hole in the casing and a bit of pipe on the outside and drew the bush out into the pipe.

Click to expand...

I used to use a similar apporach with a couple sockets the appropriate size. This year I finally gave in and made a stepped piece that centers in the bush and a bit of tube in the right diameter and length to replace the sockets. It works the same, but I don't have to worry about lining up the small socket with the bush.

Ken

Thanks KEV-C and lcrken - I didn't elaborate too much but that is exactly what I tried last - only managed to strip the threads on one bolt!
Thanks also hobot - I might just try your idea next.
Very grateful to all of you on the list - wonderful bunch.

Paul.