Hitchcocks Forum

Hi Guys
I need advice on how to separate the inner casing from the gearbox of a 1996 500cc Classic. Gearbox is on workbench. All 5 casing screws are out but cannot separate the inner casing. I thought it might be the hex head bolt just SW of the main drive but discovered (on reading elsewhere) that is the kickstart stop.
Heated the joint with my hot air gun to around 150degC and tapped with nylon hammer– made no difference.
Heated the main bearing similarly ‘cos I thought that too might be stuck on the shaft – made no difference when hit with small hammer on wood block. Harder hits with nylon block on both the nut screwed on the main shaft and around the casing gave minimal movement and the casing has eventually opened ~3mm at the top and just a tad at the base (1/10") but won’t go further.
Is it only the main bearing holding onto the shaft, as it did with the mains bearing (see below a few days ago)? Should I construct some sort of puller plate across the inner case using the 5 case holding screws and a bolt pressing on the main shaft? Does it make a difference if the box is in gear or neutral?
Any advice welcome – I hate to use BFI again.
Cheers, ChrisD
BTW the hardest part so far is removal of the old gaskets. There has to be a better way, perhaps using the correct solvent?

You have undone the nut on the end of the mainshaft? (LHT)

There's a Tech note about replacing the kick start pawl here which should help.

PeteF
Thanks for the input. The pawl tech note is more helpful than Pete Snidal's manual or the official workshop manual and has given me a clue - tomorrow evening will test.
Thanks
ChrisD
PS and the gasket solvent, anyone?

Hi CHRIS D.............. if you have removed a casing then soak it in boiling water for 10 mins or so....This works ok on paper ( Card) base ones )......When replacing gaskets just rub some grease firmly into them before fitting......There really isn't any need to use a gasket goo other than for location purposes....Make sure the mating faces are flat and true before assy. !!!

Chris in your description i don't see a mention of removing the lock nut on the detent plunger (gosa) ..

Expect you have done but if not it will hold the inner case to the gear casing..

Use a blow lamp on the alloy, keep it moving circular around the bearing. Get it spiting hot only, don't over do it..

No great force is necessary or required. some hard wood wedges can be worked in around the joint to keep things square during removal..

Hi Chris, I had to make a puller up for one box I couldn't get apart I used the 2 holes the bearing cap screws onto. The next box I pulled down I had to make up a sleve to go on the end of the mainshaft because it was 1mm undersize and the shaft was slopping around in the bearing. Such is Indian quality. I would try a bit of emery on the shaft once you get it apart to see if you can get it to fit a bit better

Gwilly, AlanR and Norm
Many thanks for the suggestions. I had indeed loosened the détente locknut and had been inserting plywood wedges where possible. Eventually I used a lot more heat but no more BFI and finally the bearing unstuck and the case separated. I shall certainly run some fine emery/Solvol around the shaft to ensure the new bearing doesn’t stick like that.
I didn’t know that soaking gaskets in water would soften them to ease removal. Next time!
Cheers
ChrisD

Hi Chris, what came apart, sounds like the bearing stayed on the shaft. The bearing is supposed to stay in the housing.

Norm
I was not as clear as needed. The bearing stayed in the casing and the shaft released from it. Haven't completed pulling it apart yet 'cos I'd mixed Molyslip into the grease and I needed plenty solvent to cleanup! Cheers
ChrisD