Crank endfloat

[MK Monty]

Been stripping a mates Muggy today. He is in the middle of a full re spray and it's not run in anger for 6 months or more. Anyway he was convinced his main drive oils seal was gone as it was smoking. Told him to leave it till he got it on the road, oil in the pipe etc. but he was convinced it needs doing so as he had already got the top end off I stripped the crank out. He has a very small amount of flywheel up and down movement but a good 1mm sideways movement. Unfortunately he had already removed the chain and the Cush drive but he recons it was the same when it was on. How much end float would you expect. He is committed now to new bearings and viton oil seals. I just don't want to rebuild it to find it's the same. To be honest the seals looked ok. The drive side seal plate was flat, I would have liked to see it run for a few weeks in case it was just a lazy seal or oil in the pipe
Any thoughts guys

[rossclark]

If you mean you could move the crank in and out in line with it's axis then I'd say you should have no movement there at all. At least within the tolerance of the bearing, which will not be 1mm...

[MK Monty]

Thanks for the reply. Yes its in and out. The crank is not moving on the main drive bearing I still had to push the crank out of the bearing. The other side floats on the inner shrunk onto the crank. Once the drive side bearing was out it looked good. Still had the inner fitted oil seal and the lips of the oil seal and steel plate looked fine. I wondered if the oil seal lip was running of the face of the crank. its very close to the edge if its moving in and out. He was complaining of vibration and thought his flywheel had come loose. He had it welded some time ago after loose rivets. The weld was fine and anyway you could see the crank move in and out on the other side. I was unsure if having the cush drive and chain off would stop it being pulled through.