Molyspeed

[JOWETTJAVELIN]

Does anybody use this stuff? Molybdenum disulphate or however you spell/pronounce it. I believe they did a test decades ago where two identical cars had the sumps drained and then ran, but one had Moly added at the oil change. The one with Moly ran for something like 10 miles longer before seizing up.

Reason I ask is, due to impending big end failure (again) I added a can of Wynn's Super Charge which has worked remarkably well in quitening the noise and giving me a bit more time - though to anyone thinking this is a 'cure all' IT IS NO SUBSTITUTE FOR A STRIP DOWN.

Moly seems to be good stuff then and certainly nothing is to be lost by using it.

Anyone else become addicted to it?

[bmcecosse]

It won't do any harm in the engine.

[DAVIDMCCULLOUGH]

Ive used molyslip in axles and in one gearbox that wasnt great. It certainly did help in the axle and even when the oil was changed the next time it was never as noisey as before. Didnt do much for the gearbox but it would have needed a miracle

[bmcecosse]

Should never go in a gearbox - will ruin whatever little syncromesh is left!

[RobThomas]

I bought an MGC with a set of close-ratio straight cut gears in it. Previous owner had put Moly in the box to quieten it down. Such a crying shame. The car sounded like the wrath of Thor when you gave it some wellie but the box was doomed.

[bmcecosse]

The whole point of syncromesh is that it 'syncronises' the speed of the gears just before the dog teeth engage to take up the drive on the new ratio. It does this with friction - and so adding Moly is a v poor idea, making the surfaces far too slippery so the syncronisation doesn't work. However - it's not irreversible - new syncro rings and a thorough stip down and cleaning should get rid of the moly, but if in the meantime the little dog teeth have been ruined by the non-syncronised changes, well - new gears and selector hubs are going to be needed........

[mike.perry]

I have always regarded synchromesh as a luxury on a Series MM gearbox!

[JOWETTJAVELIN]

Nothing in car design really changed until the 1980s; 1970s cars, or at least 1970s British cars, were basically the same as 1930s cars. No synchro on 1st and no rushing gearchanges.

[drivewasher]

Yeh you can't beat an Eaton twin splitter. luvurly shift. beats all these syncro boxes!