Morris Minor Owners Club

I have got 2 boxes the ribbed type, I want to change the one in my 948cc which whines in top gear. On checking through the side plate I can see that the reverse gear is chipped in both boxes. Is this usual, Ist it worth just replacing the reverse gear, if I can pluck up the courage to take one apart.

Well - if you don't it will always be a weak spot and may be noisy when reversing! But if it's chipped - good chance the 1st gear is also chipped ?

Are you sure it's chipped and not just slightly worn on the leading edges of the teeth? This is quite common and not really much to worry about. They wear on the leading taper as they mesh with 1st gear which is a straight cut gear. As long as 1st gear is OK and reverse gear is not chipped on the main section of the teeth, they should be good.

That said, reverse can be replaced without total strip down.

That said, reverse can be replaced without total strip down.

Please tell me more, It is just the very edge of the teeth, one box it is a single tooth, the other it is all the teeth, both on the small cogs, the other cog looks ok.

Just go with the single damaged tooth box!

Just go with the single damaged tooth box!

I am just investigating my different options before going to all the work of fitting the box. I am going to have to factor in the cost of a new clutch as well as replacing other parts that will be required.

Please tell me more, It is just the very edge of the teeth, one box it is a single tooth, the other it is all the teeth, both on the small cogs, the other cog looks ok.

A single chipped tooth on leading edge of reverse is nothing to worry about. I would go with that box and leave well alone, considering that some 'new' replacement parts are of dubious quality. Replacement involves removing the remote housing, side cover, reverse detent ball spring and plunger, reverse selector fork, reverse gear idle shaft, and then fiddle the old gear out through the side cover hole.

Re-assembly is difficult but possible, without removing the laygear etc.

A single chipped tooth on leading edge of reverse is nothing to worry about.

I have had a closer look at both boxes today, The one with the single chipped tooth is not as smooth to turn as the other one. The chipped tooth is almost half the length of the gear. The other box is much smoother to turn and all the teeth are chipped but just on the corners. The only other unknown quantity is the state of the synchros. I might just try the second box when the weather gets warmer and keep my fingers crossed. My mate wants a clutch in his moggie so I might have a summer hefting engines and boxes in and out. Thanks for your input.

Aha - you're expecting a two day summer then
a

might be worth looking at buying a crane if you dont have one already!!! makes life soooo much easier!

Or - just use a swing!


Thanks to Badfelafel for the picture - and for letting me play with his engine!
But if the 'chip' is half the length of the tooth - well that's more than a chip! Inspect the little dog teeth on second gear carefully - that's the one that takes the most punishment. That box may just need to be flushed over with oil to make it turn nicel - give it a try - and then see how it turns.

we bought an engine crane off ebay, although I have used a similar set up to the swing in my youth. With the radiator and front panel off access looks to be the best I have ever had, shoe horns not required. My mate reckons he knows a bloke who lifts moggie engines out with a rope slung round his shoulders. I have never met him and if its a dark night I don't want to.

Before swing - I did lift them out (sans head) by hand. front panel off is well worthwhile - especially if gearbox is attached!

Up date. The box with a single chipped tooth on reverse is no good. When I removed the selectors I could see excessive wear on the other cog. The second box is much better, just a bit of wear on reverse gear..Have ordered a seal and bearing rebuild kit, a reverse gear and 3 synchro baulk rings for the sum of £94 delivered. The seal and bearing kit includes gasket set 3 indents 3 needle rollers 2 ball races a layshaft, reverse gear shaft and tailshaft oil seal. I have stripped the box without excitement and will rebuild it and have change out of £100

Good idea - well done. Years since I did one of these boxes - although have done many v similar Mini boxes since. Just don't lose any of the wee balls and springs - and be sure to get the interlock bullets back where they came from!

The wagon driver at work has changed moggie engines by the "straight lift" aproach in the past - rope over his shoulders, straighten up, and out it comes...

It must be nice having cars where that is (just) possible. I can just lift a landrover gearbox onto an engine - the engines are the best part of a quarter of a ton, so its a crane (or tractor with a loader) job...

can anyone tell me please what should the size be of the brass bush, at the pinion end of my 1098 gearbox. Its the one near the pinion oil seal.

On the gearbox outlet section ? Dunno the size - but must be a snug fit for the propshaft - so if you have a shaft handy ...

I bought a reamer for this bush a while ago, if you still need to know I will have a look for it and give you the size.

No the shaft is still on the car, I've ordered a new bush, I could do with know what size, in case it needs reaming before fitting the tailshaft seal.