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MG Midget and Sprite Technical - Frogeye gearbox - 3rd motion shaft removal

All,

any suggestions on how to remove a stubborn 3rd motion shaft from a smooth casing frogeye gearbox? the original manual suggestion of "draw out the 3rd motion shaft" with a picture of a hand simply pulling it out isn't cutting it, the Haynes - tap lightly at diagonals also isn't cutting it as I cant actually get access to tap lightly diagonally, everything else is free or dismantled and I'd like to get it all apart to inspect the workings and soda blast the casting

All and any suggestions gratefully received

Thanks
Alan
a reid

How about holding the shaft in one hand and gently tapping on the back of the case with a rubber mallet?
mog

Maybe heat the housing as being aluminium it'll expand more than the bearing and allow it to be pulled free.
David Billington

I used a large mole wrench clamped on the shaft, then held the clamp whilst tapping the case with a suitable faced mallet (wood was better than rubber!). The bearing carrier gradually emerged. You have to be careful once the housing is almost out it doesn't cause the gears to foul.

Another option is to tap the housing out through the side aperture with a long thin brass drift. I found this quite a faff though.

You just need to get the lip of the housing out and then you can use a small pry bar working round the housing to free it.
Bob Beaumont

Alan,

Aluminium is softer than brass. I could not get the bearing housing out without scars, on the inside I did tap it out from the side cover aperture with a soft metal drift and a heavy metal hammer. I could get 2 screwdrivers under the lip. It took me half an hour to separate it from the casing. Pushing it back was 30 seconds.
A mole wrench is a goog idea, I never tried.

Flip
Flip Brühl

Thanks all,

i had been trying to drift it out with a piece of hardwood from the side opening and it wouldn't shift, managed to get a large washer through one of the gear selector holes (with the recess cut out on the inside of the casting and tightened from outside with this side showing some movement and then drifting the other side and still no joy. Never crossed my mind to hit the outside while holding the shaft! Ill try that first and if that doesn't work I'll give it some heat - may thanks

Alan
a reid

So, eventually managed to get it out, tried holding and hitting the outside of the casting but still no joy. After much searching through the "must keep as this could be useful" bin I came across a thick metal plate with a hole in the middle, removed the worm gear off of the main shaft and fitted the plate in front of the distance piece and added a couple of bars either side of the large bearing and tightened the 3rd motion shaft nut up and it came out a treat :-)
a reid

Result
mog

Well done. Another method to try!
Bob Beaumont

This thread was discussed between 31/03/2016 and 05/04/2016

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