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MG Midget and Sprite Technical - 1500 gearbox advice please

Gearbox, 70K miles, owned since 1983. Gentle use but a fair bit of flat out for 4 years when I lived 40 miles from work!

Gearbox seems to be in great shape - only stripped because for the last two years I have done a piece part restoration of the whole car. I used to work as a Mrine fitter but have not built auto gearboxes before.

The baulk rings seem very good, no nicks, no wear or pick up on shafts.

Gear teeth all good except reverse gear which has some wear on the gear edge (possibly from trying to engage when running forward?) but shaft is good. Reverse gear wobble on the shaft is about ~3/64 inch but Im not sure if that is OK (seems a bit high and Ill see if I can compare to a new set at Moss), there is no wear marks on the shaft.

So what to do - needles all good, I will change the mains but what else.

To me it it is good to build as is?

N Kirk

Picture of reverse idler gear showing wear on edge of gear teeth

N Kirk

Looks all good.
Check the gap between the 2nd synch ring and the gear with pressure on, compare to others, should be about the same - that is the most common wear item.
BIG problem with these boxed is breaking the nasty circlip that retains the 3rd gear hub, as a result of overstressing it in removal or installation - best to leave it alone. I've had several where this broke in service - scraps the shaft and much else.

FRM
FR Millmore

For a 1500 GB - that is pretty tidy
C L Carter

If I remember correctly, the layshaft and it's associated needle bearings are prone to wear, and the main shaft bearings can get noisy.

Malcolm
Malcolm Le Chevalier

Layshaft and the needle bearings are very good, main shaft bearings particularly the first motion shaft which feels a little worn are being changed out for some old RHP Made in England bearings from Moss in Bristol (UK)

Today a guy at work (Rolls Royce) has advised the reverse idler to be replaced and to 'mic' up the shaft looking for ovality. I will get a second opinion on the baulk rings tomorrow.
N Kirk

This thread was discussed between 17/02/2013 and 18/02/2013

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