Gears stuck on layshaft?

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SEDoan
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Gears stuck on layshaft?

Post by SEDoan »

The gears on either end of the layshaft are seized onto the shaft. How does this happen?
Layshaft.jpg
I've banged the shaft down on a block of wood - no movement. Supported the first gear and pushed with a press. Not much pressure so as not to break the gear - still no movement. Thought I would ask on here before going Conan the barbarian on it.
There is no evidence of peening or wiping at the end of the spines that would suggest the gears are welded to the splines. Does this happen sometimes?
Would someone locktite the gears onto the splines?
How much heat could the gears tolerate without softening?
Any other ideas?
Thanks,
Shawn
1937 Guzzi GTV, 1939 VH bitsa, 1947 VH, 1981 Guzzi Monza, 1983 Guzzi Lemans
nevhunter
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Re: Gears stuck on layshaft?

Post by nevhunter »

I've seen the splines crumble and that could lock them in place. Someone could have used loctite but that would make it difficult to assemble. Nothing softens till temper colours appear. Light straw happens first. Burman gears are not particularly hard. Nev
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Re: Gears stuck on layshaft?

Post by SEDoan »

Thanks Nev. Will try a little heat and let you know what happens.
1937 Guzzi GTV, 1939 VH bitsa, 1947 VH, 1981 Guzzi Monza, 1983 Guzzi Lemans
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Re: Gears stuck on layshaft?

Post by SEDoan »

I put the stack in the press and heated the gear until grease bubbled out the spines. Despite this it still let go with a bang and then creaked loudly with every push. Flipped the shaft over and repeated the for the same result. The raised surface of both splines has scratches from the contact with the gear, but otherwise look OK. The gears slide normally onto the 2 other shafts I have.
1937 Guzzi GTV, 1939 VH bitsa, 1947 VH, 1981 Guzzi Monza, 1983 Guzzi Lemans
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Re: Gears stuck on layshaft?

Post by JohnnyBeckett »

hi i would try using a wire wheel on a bench grinder to give the shaft a good clean and you may find i will let gears move freely
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Re: Gears stuck on layshaft?

Post by nevhunter »

They are not usually that tight. Perhaps the shaft is not genuine.Clean and lap them a bit.Press on and off in various positions. The splines are not indexed. Hard to assemble the box if they are tight. Nev
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Re: Gears stuck on layshaft?

Post by SEDoan »

The speedo worm is damaged so shaft needed replacing anyway. The gears seem fine. Thank you both for your help and ideas.
1937 Guzzi GTV, 1939 VH bitsa, 1947 VH, 1981 Guzzi Monza, 1983 Guzzi Lemans
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