Gearbox cracked

[hanvyj]

I was fitting my 1275 engine today and didn't know the alignment notch hole in the gearbox needed drilling larger so tightening the bolts cracked the gearbox bell housing.

Is it a big job to replace the insides of a gearbox?

Are there any alternatives I should be considering to a morris minor box for the 1275 bearing in mind it had the backplate/flywheel ready for the standard box?

Also, does anyone have a knackered gearbox they are willing to part ways with?

The damage:

[callyspoy]

Not overly sure just how bad it is, but i once had a Minor gearbox with the top part missing, it was fitted to my car with no problems.
Not saying it's right, or that it is recommended, but mine was fine.
No price on peace of mind of course.

[bmcecosse]

Hard to tell how much of it has cracked away in that shot - it must surely have been obvious you were having to put a LOT of strain on the bolts....... It can be welded of course - or just ignore it till you have the box out again for some other reason. Not ideal - but it won't come to any harm as long as all the other bolts are snug.
It would take a couple of hours to swap the internals into another bare casing - do you KNOW the internals in your box are in good condition? Maybe just source another 'known working' box meantime?

[hanvyj]

It's only the bit around the top right bolt that has come away. Yes, I should have stopped when it started getting much harder That will teach me.

I've decided to keep it with that one bolt off (well, actually just holding the piece in place so loads of junk can't get into the clutch) and I will keep my eyes out for a new gearbox.

I know its a working box, not had any problems with it for the two years I've had the car - I don't know if its good though, for all I know it could 'go' tomorrow. Makes no noises and works fine.

I was told the minor gearbox might be a bit prone to problems running a 1275 anyway what with the additional stresses - can you fit a marina/midget gearbox? Would I need to change the backplate of the engine back to a midget one (instead of the slightly thicker one) to fit one of these gearboxes? Also do they fit with the propshaft.

Love a type 9 but they are about 2k for the fitting kit & gearbox!

[bmcecosse]

The Minor box will be fine -a standard 1275 produces v little more power than a 1098. Don't worry about it. Yes you 'can' fit a marina box - but it's not a great box, and a v tight fit between the chassis legs.

[IslipMinor]

The 1098/1275 'ribcase' gearboxes will interchange from a fitting point of view, same spigot bearing size, same backplate for the same size engine block, same propshaft fitting, but internally they are not all the same and not interchangeable in many ways. The Marina box used with the 1275 is different, as in the previous post.

The 1275 box was only ever fitted to the Midget/Sprite and had different (closer) ratios to the Minor 1098 box. The 1275 also had needle roller bearings for the 3 mainshaft gears, replacing the phosphor bronze bushes used on the non-Midget/Sprites. The later ones has a reverse light switch built in to the remote housing as well. The Midget/Sprite 1098 box also had the different ratios and needle roller mainshaft bearings.

There is another possible difference between the Minor and 1275 gearboxes - the length of the carbon thrust bearing. The 1275 clutch is much thinner than a 1098 and I think some compensation was made in the height of the carbon thrust?

[charlie_morris_minor]

this is on ebay in hampshire somewhere so might be close to you?

http://www.ebay.co.uk/itm/Morris-Minor- ... 460eb0103d

[hanvyj]

Thanks, I'll keep my eye on it