THIS HAS GOT TO BE ONE OF THE HARDEST JOBS TO REPAIR
Unfortunately for me I’ve done a few of these and it proves 2 things – Lambretta casings are a crap design especially here. If you’re wrongly hammering in a drive bearing and you’re not careful you can go straight through! This would normally scrap a casing!
But with the machines and a bit of know how you can repair them the best you can without scrapping a casing.
This one had already been in for a rear hub bearing area repair, it had been picked up then the customer went and broke the drive side area!
It is one pain in the arse job to do, the hard part is getting in to weld the new plate which I have to machined up as a one off. Then once welded I’ve purposely not ground the weld just in case it finds a hole that may leak and you hope there’s no porosity. The bearing hole distorts, so you need to hone that to size and a round shape – nightmare!
Then it’s lots of heat, then with our new handy tool seal the outside of the bearing as belt and braces and pull the bearing in with the correct pulling tool, then let it cool down.
This bearing is what we call the touring bearing with one seal – and for the idiots that say don’t use this bearing – well once again it’s the non qualified non engineers who talk rubbish all the time.
Yes its only a grease seal, oil can pass through it. but it helps to hold off the preessure from the gearbox oil on the drive seal.
And it works like this……..
The drive seal is fitted with the spring towards the crank, the pressure of the crankcase pushes on the seal onto the crank to seal it from the gearbox. This seal is lubricated by the petrol oil mix with a fine bead on the sharp part of the crank seal face so it doesn’t burn out. Now the extra drive bearing seal that is our biggest selling bearing helps stop gearbox oil in the crank seal area. As standard with one seal it’s more prone to leak and if it does it’s a big job to do it again.
As an example in the 90’s I did an engine for slacker who works for us, he did 20’000 that year, When it came in for a freshen up the drive seal had totally gone but with the touring seal in place it did not burn oil – proving it can help an engine!
All in a days work.
