Dommie oil pump seal

I think there may be some thicker gaskets to be found. Check there is no shim behind the pump seal, Pumps sometimes are fitted on a gasket which  was not std and may not be needed.  As a last resort the pump may need a skim ?.

Two versions of the intermediate spindle were made for the Dominators.  Please do not ask me why. One has a double helix oil spiral and the other a single.  Check photo.

One has a tapered / chamfered end which enables it to fit the dome recess of the timing cover oil seal. This effectively reduces its length by around 20 thou.  One solution to the gap problem.

As Robert points out the standard Dominator TC gasket is thin at around 10 to12 thou whereas the Commando versions are generally between 22 and 25 thou. This helps to overcome the problems of old covers with dings or are twisted. The downside being this thicker gasket could make the oil pump seal a bit of a sloppy fit. Generally most good parts suppliers offer the latest Commando version of this seal which is thicker and softer. Hence suitable for Dommis or Commandos. Or you could shim the earlier version.

makes you wonder if you could use an alloy filler, like they use on wheels just to smooth things out.

barry

to fill this sort of thing, but I'd use a smooth flat file first to get rid of any "inverse" dings that might have raised the mating surface.

Having said that your .032" gap does seem much too big - are you using a Commando type oil pump seal or the normal fibre washers?

HiTony,

I know you said you weren't a fan of RTV silicon, but Loctite 5660 is grey, similar in colour to engine alloy and will mean you have an oil tight Norton.

Applied properly you probably won't even know it is there.

The Japanese bike makers all use a similar sealants  - Yamabond, Kawabond etc, even on split level sumps where the joint is below oil  level, and they don't leak. I consider it as a modern, well engineered solution to a problem, not a bodge. (Unless you think of RTV as  that bright orange stuff from the late '70's-that did look like a bodge!)

Regards,

George 

Rooting about in my garage a few months back, I came across a box containing a tube of Silver Hermetite.I haven't looked for a date on it, and it probably doesnt have one. I must have had this for 30-40 years, so its purely of novelty value. Perhaps 'Enry Cole will offer me a fiver for it!

.. was fitted to singles and I understand also to twins although I see AN list the Commando type. My parts book for the 1956 twins shows part D2/133 which I think is the same part as that specified for the sinles ie A2/133.

It's odd (and now I'm boasting a bit) but my timing cover with thin paper gasket never leaks...

But the Dommie shouldn't be compared with the Singles. The Twins have shell big ends so the pump gives high pressure (at least when cold), which is why the crank is fed through the garter seal. The Singles have ball bearings, so the pump just has to send volume at low pressure (hence the 'quill' feed to crankshaft.

The Commando rubber nipple on the pump is thicker than the Dommie. That can mean it gets squeezed both outwards and inwards.  The last one I took out looked to be on the verge of losing bits of rubber...

conical rubber piece, and has had from new.  No fibre washer used there.

Let he who is sinles cast the first stone....

... working from the original Norton parts list although I accept that these may have been incorrect. Have you had your Dommi from new then Paul?