Morris Minor Owners Club

Hi all - the MM manual says the 1st motion shaft should be tapped out into the bell housing using a rod, on mine the synchro teeth are too wide to go through the hole that the bearing fits into. Does the shaft separate or should it be removed by exiting INTO the gearbox casing (rather than OUT OF the bee housing. G/box is a late 1098, thanks, John

Yes - it has to come out in-the-way, if you see what I mean!!

Thanks bme - not sure what ypu mean tho?

If it can't come out the front bearing hole - you will need to bring it INTO the box to remove it through the side cover! So - it's last out - and first back in!

BMC

Are you sure? I thought that the first motion shaft bearing is held under the front cover with the clutch pivot. You simply undo the cover nuts and tap out from the inside into the bell housing?? Or do you have to remove the bearing circlip and tap it into the gearbox?

edited

Taupe

It's many moons since I did it - but southerly reports syncro teeth are too wide to go through the hole - and I do vaguely remember something about that.

Thanks - looking at it I dont think that pushing the bearing back thru' the gearbox housing and then out into the casing will work as it looks like the layshaft gear will get in the way (even with the layshaft out). Sooo I think I'm going to remove the 1st motion shaft nut and bearing then push the assembly into the housing that way as it should have 'wiggle room'?

I think you do have to drop the laygear in to the 'base' of the gearbox.

Having just returned from a refreshing cruise in the Med I went back to the g/box and low and behold the 1 motion shaft simply taps INTO the gearbox housing even with the laygear in place (but with layshaft removed) - much as bme suggested. Have got a new laygear from ebay but the manual suggests a new 1st gear hub as well. Any views? Btw I got a new layshaft because the endfloat is greater than the recommended tolerance even with the thickest rear thrust washer - there are no new front thrusts around for love nor money - unless you know otherwise? Regards, John

Just inspect your 1st gear and decide. The heaviest wear in the box happens when folks ram 1st gear into engagement and chip the teeth on the laygear and/or 1st gear (similarly in reverse) and of course the little dog teeth on 2nd gear take heavy wear when folks don't double de-clutch, to the point where the box starts to 'fall' out of 2nd gear on the overrun. So inspect those dog teeth carefully - compare them with 4th gear which 'never' wears. New syncro ring for at least 2nd gear is almost certainly needed too. The layshaft and it's needle bearings often wear - and the endfloat is not that critical - you could put a shim behind the thrust washer - next to the box casting if you wish. The laygear is only likely to show damage on the 1st gear teeth - unless something solid has gone through the gears!

I compared old and new laygear and the 1st gear teeth are worn at 45% along one edge, they were worn uniformly so they didn't look out of place until I looked close up. Looking at the 1st gear teeth I can now see the same wear on them so have ordered a new one. 2nd gear is more difficult to evaluate - about half the dogteeth are the same size as 4th gear but of the remaining teeth they are at an angle with some as low as 30% missing and also at an angle from the base of the tooth.

As it's slipping out of 2nd gear I am trying to remedy this looks like the culprit? I am replacing all of the baulk rings but don't think they are a factor with slipping out of gear? Regards, John

I think you certainly need a new 2nd gear then - if it was slipping out. You probably only need a new baulk ring for 2nd gear (in Mini 'world' - there have been problems with baulk ring quality reported, and so new-old-stock is to be used if you can find any!) - and of course - you should look closely at the syncroniser hub for second gear - has it been damaged by the worn dog teeth ? Hopefully - a new 2nd gear will solve the problems. Here's a pic of a good goldseal gearbox - with unworn 2nd gear dog teeth. You can see that the teeth on 2nd are pretty much the same as those on 3rd and 4th. And as I indicated before - 4th never wears ! [frame][/frame]

Thanks BME - oh dear it looks like I need a new 2nd gear then. I have a new 1st gear on order which will give good dogteeth on the hub side - any ideas where I can acquire a new or good s/h 2nd gear?

PS I had a senior moment yesterday as I couldn't find the 4th gear cog - had forgotten it was on the 1st motion shaft! Regards, John

No - it's on the third motion (output) shaft! The new 1st gear will just be that -1st gear - I don't think it will include the 1st/2nd syncroniser! What you can see in my pic from left to right is 2nd/3rd/4th gears. 1st gear is hiding inside the selector fork for 1st/2nd . Over in the lower left - hiding in the darkness - can just be seen the straight cut teeth of the 1st (and reverse) part of the laygear.

We might be talking at cross purposes

In this pic (if it comes out ok) is first gear (badly worn), sitting on the synchroniser hub. You can also see the worn dogteeth on 2nd gear. What you can't see is that the matching dogteeth inside 1st gear are also badly worn and I suspect this is also part of the problem. So, with a new 1st gear having new internal dogteeth these should 'bite' onto the 2nd gear a bit better when 2nd gear is selected, if it doesn't then I will have to source a replacement 2nd gear.

Looking at the pic again, I assume the 2nd gear dogteeth, when new, should be almost touching the teeth on the synchroniser hub, regards, John

[frame][/frame]

Yes -sorry - you are of course correct! I'm a bit confused after working with Mini all-syncro boxes. Try the new 1st gear and see how it looks - although 2nd gear is a bit out of focus - it doesn't actually look all that bad - and of course - 4th gear is on the input (1st motion) shaft - I had it the other way round in my head! I would put a new syncro ring in 2nd gear though.

Well here is the 3rd motion shaft reassembled

Only question I have now is I can't find guidance on the recommended end float for the 1st/2nd gear synchro hub? Play is about 20 thou side to side on the shaft ( i.e. it moves back and forth along the shaft by 20thou) and not sure if that is within tolerance or whether it doesn't matter? Regards, John[frame][/frame]

Sorry - I have no idea! Is that with the old second gear still fitted ? New syncro cone ??

Yes this is with new 1st gear and new layshaft with all needle and roller bearings replaced including the 2nd/3rd bushes. Not replaced 2nd gear as I can't source a new one. Also going to check that the selector forks are in good condition prior to reassembly.

Thinking about the question I asked about endfloat, it the 2nd gear assembly can't move anywhere and the gear selector governs the position of 1st gear and as the 1st gear hub has long splines these 'should' be long enough to join 1st and 2nd across the dogteeth therefore end float shouldn't matter.

Thanks for help with this, I will know soon enough if slipping out of 2nd has been eradicated. Regards, John

There's bound to be some 'free play' - good luck with it! I always found it very satisfying to rebuild a gearbox (mostly Minis) - provided they work of course!