Model c oil on floor after full rebuild

[johncas]

Had a full engine rebuild on my model c but noticed oil on the floor today fresh oil do I just need to tighten the screws because after a £3000 engine rebuild you should not get leaking oil

[Rob Miller]

I had the same problem with my C. The result was an embarasing pool of oil on the floor at Brid. custom show. If you overfill the gearbox, oil will leak from the kickstart housing.

[jbcollier]

Clean everything up carefully and watch to see where it's coming from. There are three types of oil:

- 140 gear oil in the final drive, most like to leak from the rear wheel oil seal. Later cases added a breather which helps a lot.

- 30 engine oil in the tranny, overfill as mentioned above, loose plugs, gaskets, etc.

- 2 stroke mix, yup I once ordered gaskets and seals because I had a fuel leak -- thankfully I figured it out before stripping the engine. The fuel taps are notorious for leaking. The petrol evaporates leaving, you guessed it, oil.

[ladsdad]

£3000!!!! just for the engine!!! Wow......

Firstly if I'd spent anything like that on a rebuild, I'd be having a word with whoever had built it but to be honest I think you're expectations may be a little high of your poor old "C" as I doubt they were ever intended to be leak free seeing as it was 1950's cheap transport for the masses.
My C dribbles a bit from the transmission knuckle joint & after a run sometimes the exhaust flange, airfilter & various other points as well. If you intend using it, it will leak no doubt about it...If you go to a motor museum, generally the bikes/cars that are running have pans underneath them to catch the drips.
Still like you say, may just be something simple that needs tightening up...

Good luck Mark.

[Steve J]

Clean everything up carefully and watch to see where it's coming from. There are three types of oil:

- 140 gear oil in the final drive, most like to leak from the rear wheel oil seal. Later cases added a breather which helps a lot.

- 30 engine oil in the tranny, overfill as mentioned above, loose plugs, gaskets, etc.

- 2 stroke mix, yup I once ordered gaskets and seals because I had a fuel leak -- thankfully I figured it out before stripping the engine. The fuel taps are notorious for leaking. The petrol evaporates leaving, you guessed it, oil.

Only two types of oil in Model C - the 140 grade oil was an improvement introduced for the D/LD models - prior to that Lambretta used a soft grease for the final drive section.

[Angry Bloke]

Hi - Newbie question but how much do I put in each section or what do I level it to ?

Cheers

Peach

[Steve J]

The gearbox oil is the same as for the later shaft drive machines, quoted as SAE30 in summer, and SAE20 in winter. Straight SAE30 grade oil is still available, but I'm sure that 20/50 engine oil is fine - that's what I always used in my Ld. Quantity is about 1/2 pint - there is an oil level plug on the clutch housing on later shaft drive machines, but I'm not sure the Model C had one.
I've got a lot of data on the NSU Prima D, which was very closely based on the C model, so lubrication recommendations for that machine are probably much the same as the C model. Gearbox oIl data is given as being 0.57 pints (0.3 litres) of SAE30, or 80 grade gear oil (which is probably just a bit thinner than the ST90 oil used on post 1958 Lambrettas.) Grease for the rear drive and suspension was quoted by NSU as being "10.5 ounces of Epix or pressure lubrication grease" or Shell Retinax G. Both these greases have been superseded, but it needs to be a fairly soft type, similar to the sort of stuff used in vintage car steering boxes (Penrite Steering Box Lube or Shell Gadus S2 V220 as examples.) As far as filling the rear transmission is concerned, one method seems to be to remove both filler plugs, raise the rear wheel clear of the ground, and run the engine in 1st gear. Feed the grease into the forward filler until it can be seen through the rear filler hole - but don't overfill it or it will find its way onto the brake shoes. Maybe someone has information which is specifically for the C model, but the NSU recommendations may well be the same. Hope that's of some use!

[Angry Bloke]

. Hope that's of some use!

Brilliant- thanks Steve