C J,

There is a maximum fill level for the gearbox set by the black slot headed screw below and left of the selector ramp.

The bushes are not intended to be oil tight

Regards Brian

Hi C J Had a close look at my S7 [1977/8] and there is no bushing in the gearbox casting for the lead-screw it runs in the gearbox main body.

As far as oil leaking out if your oil level is the same as mine then "full" is level with the bottom of the lead-screw hole so little oil should leak out — is it possible you are overfilling the gearbox or maybe the level plug is in a different position due to design changes over the years? Remember the gears etc are splash lubricated.

The oil level plug is left of your finger in the photo on the end of the gearbox, it is not the large domed screw on the front LHS of the gearbox — this is there to facilitate fixing the gearbox the machine and allows entry for tightening a screw that holds it against the bed casting.

Cheers John

No bush is going to be oil-tight. It would seem that the gearbox has simply been over-filled. I would expect JF is spot on as the pic would suggest (from the stamped lettering/numbering) that the level should be no higher than the bottom of the bush. Oilite bushes require the minimum of lubrication as they are either like a sponge or impregnated with virtually a lifetime lubrication at manufacture.

CJ,

What you have been told so far is correct, no iolite or other bush will retain oil. The whole Myford lubrication philosophy is one of "total loss".

Oil should be added up to the level screw and not above. after refilling leave the level screw out for a while as it is of small diameter and it will take some time for the actual level to establish its self.

You do not say what grade of oil you use. Never use Esso Nuto or any other H32 grade oil in the gear box. The instructions that came with my gearbox (one of the last made at Beeston) states on page 2 that K68 oil should be used however later instruction in the book (page 15) specifies SAE 30. Both of these oils have a higher viscosity that H32 and K68 is clingy and less likely to leak through a small gap.

Are you sure about the OD of the bush as Myford would surely have used a standard 3/4" OD bush rather than go to the trouble of machining a standard it down for no good purpose?

I have a 5/8” bore x ¾ x ¾ Oilite bush that you can have or a 5/8” x 7/8 x 7/8 if you have to machine one down to an odd size. Send me a PM if you want one.

If the leadscrew is badly worn or has a rough surface it could be reclaimed by having metal sprayed onto the worn area which is then reground to your required size. When I was running an engineering department I had two very good suppliers that offered this serves with very fast return times. One was in Luton and one in Northampton. This is Avery good and accurate way to reclaim worn shafts.

Eric.

I imagine that the original casting of the gear box has become worn, and someone has had it bored and bushed.

With reference to a bush looking like steel, Oilite make sintered cast iron bushes. Or some machinery I have seen had steel bushes with white metal as in the bearing shells on an automotive crankshaft.

Oil leaks, British oil warning system, if there is an oil puddle on the floor, there is probably oil in the machine.

Ian S C

Found in earlier Morris Minor engines at the rear of the crankshaft for another and possibly at the tail shaft of the gearboxes. Made redundant, mostly, by contact seals.

Lots of inclined powder screws employ a fine pitch at the bottom end to prevent powder leakage.