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[Davedup]

Hi folks, recently took my '59 Super Meteor to Sammy Miller's for the ride in, a round trip of about 110 miles.
Bike ran really well (first long ride)and the engine was pretty oil tight, just a little from both cylinder heads which have been re-torqued now and I'll pull and re-gasket if necessary.
Fitted to the primary chaincase is a breather arrangement which has a pipe which comes out the top of chaincase ends above the rear drive chain with a cover bolted over the top of it. I'm getting a fair bit of ATF blowing out of here, enough to make a patch when stopped.
Is this normal? Is it worth putting a longer pipe to vent at the rear of the bike somewhere, or is there a mod for this?
Looking at the parts book, I can't see this shown on the '59 parts book but it is on the '60. The inner chaincase has had a repair inside at some point and of course may not be the original. The outer had the numbers 5242 and W42116 inside and may not be original?
Many thanks
Dave

[Mark M]

Dave, it sounds as if you have the primary chaincase inner from a 1960 onwards Twin, Connie or SM. Where does the breather from the bottom of the barrel on the left side go, to the chain or to the top of the oil tank?

REgards, Mark

[Davedup]

Hi Mark, the breather from the bottom of the barrel goes into the oil tank.
Thanks
Dave

[Mark M]

Cheers Dave, it sounds as if you have a 1960 specification machine, the model year in British factories ran from September to August (when the Factories took their summer break) so a late 1959 bike would have been built to 1960 spec. Your primary breather is therefore correct and the reason for your over-oiling is probably the crankshaft drive side oil seal failure. Although having said that in my experience even when they are in good condition they do blow a bit! And don't over-fill the primary, stay under capacity rather than over.

REgards, Mark

[p]

I'm not familiar with your model, but what is bad for the garage floor is probably good for your chain! Is it worth fixing a temporary (or permanent?) catch can so you can ascertain the extent of the oil being blown out? If it's the crankcase seal, which sounds plausable, then perhaps engine oil is also building up in primary case.... wonder if the level has gone up?

[Davedup]

Thanks both, amazing info as always Mark, had no idea about the months and years naming, I'll look at the 1960 partsbook, according to the info I have it was dispatched from the factory 15/09/1959 so that makes total sense.

Can that seal be replaced by removing the chaincase, (sprocket and electrics (12V conversion already done) etc) or do you need to go deeper into the crankcases?

It is difficult to check the level in the primary chaincase as the level screw has been stripped and a nut and bolt "glued" into place. The previous owner made up a dipstick at the right length but it is possible that it was on the high side I guess. I might invest in a helicoil set the right thread and try for a proper repair. I was intending at the end of the summer to strip the chaincase out. The clutch has some play on it and I suspect the bearings might be worn. I picked up a NOS clutch drum to swap it out with although it's working fine at the moment. There is some scoring on the inside of the chaincase but that appears older and there's no strange noises from in there.

Also looking at the parts book, my inner case looks different to the picture as it doesn't have the grommet and grommet housing, just a hole for the wire to come up through.

Thanks P, I can confirm that the chain is well lubed!
The engine oil level isn't dropping but I'll keep an eye on that.

I'll keep an eye on the chaincase level if it stops dripping just to see if it's found its natural level or emptied!