Morris Minor Owners Club

I have what I believe is a 1098 rib case gearbox behind a 948 engine. It has started to jump out of 3rd both when accelerating and on the overrun. I have no idea what causes this, can anyone offer any suggestions as to the reason? The only solution I have been offered so far is a complete rebuild for many hundreds of dollars, which doesn't attract me. I am really hoping for something simpler to try! .thanks. John

Jumping is usually a symptom of a worn box and generally means an overhaul is due. The mog box is not too dfficult to do yourself and doesn’t need special tools.

I've the same problem on a 1275 MG Midget ( virtually identical gearbox) which jumps out of gear on overrun on 2nd. i've been told it is symptomatic of worn syncromesh bushes.

Yes its a sign of general wear pretty much all round.

All of these gearboxes are really easy to overhaul, there is nothing wildly complex to them at all, even if you have never done anything like it before.

No special tools required, just a methodical way of working.

Something at the back of my mind tells me this can occur if you have a 948 gearstick in a 1098 box?

Might be worth looking at 1st

a 948 gearstick in a 1098 box?

A good thought. The bottom part of the 948 gearlever is shorter than the 1098, so that plus a little bit of wear could mean that 3rd/4th is not engaged fully, so might jump out.

Definitely worth checking the gear lever and also the plastic cup at the bottom of the lever - if that is missing/broken/badly worn, it could also mean that the gears are not being fully selected.

Thankyou all for your replies. A few things to think about, I have previously dismantled and remantled a 948 box so I'm not too worried about that,except that I live in a retirement village and have no workshop space or even a bench. Also once I have it apart I would need someone knowledgeable to look at the offending bits and assess what is stuffed and what is usable
Wrong gearstick, possible but unlikely. ,1098 gearboxes are unobtainable in Oz as they were never sold here. I bought this one second hand advrtised as being an Mg midget box
It was fitted with a curved slightly shorter stick than my 948 box . The end was the same length as the 948 stick which seemed wrong to me so I got a 1098 stick from ESM, when fitted it was impossible to move . I then put washers under the plate thus lifting the stick slightly after which all was well, perhaps a derangement at the base of the stick? How do I get to this? Should the plastic cup be visible when the stick is removed?I can't pick up the plastic cup in any of my workshop manuals.
Hope the above makes some sort of sense. It's Sunday morning here and I'm not feeling all that bright
Cheers JohnG

John
Good morning to you.

https://www.moss-europe.co.uk/shop-by-m ... minor.html

Item No: 23 Pt No: 2A3467.

If you have to pack the underside of the gearlever retaining plate (item No: 29) there is something wrong. Either the wrong gear lever is fitted or there is an additional item under the bottom of the gear lever and/or inside lever selector rear Pt No: 2A3388 (item No: 45) which should not be there.

See the above link for assembly details.

Phil

Thanks Phil. After looking at the Moss diagram I am pretty sure I don't have the Nylon cup or spring.haven't had time to look today but will do so Asap. In the meantime I have organised a second-hand cup and spring from a local sprite specialist . Fingers crossed and I'll report back
Cheers
JohnG

Thanks Phil. After looking at the Moss diagram I am pretty sure I don't have the Nylon cup or spring.haven't had time to look today but will do so Asap. In the meantime I have organised a second-hand cup and spring from a local sprite specialist . Fingers crossed and I'll report back
Cheers
JohnG

John,

That doesn't explain why you have had to space out the gear lever from the extension. As Phil says, there appears to be something wrong here.

Is the gearbox in the car? If not, can you read the part number from the primary/first motion shaft from inside the bellhousing? This part number is unique to the application, and would help to positively identify the box you have - the list of them is attached below: The other way is to identify the ratios, but that will only give you confirmation if it is a Sprite/Midget box.

Thankyou Richard. The box is in the car,however before installing it Is checked the input shaft for a number but could not find one .Thinking I must be getting dementia I the box to a Sprite specialist. he confirmed the lack of a number but doubted it was from a Sprite/midget. He suggested it may be a super rare (in Oz) 1098 box. I suppose sometime in its past the input shaft may have been changed
I'm thinking that the Nylon cup may have broken up and been removed leaving fragments at the bottom of the rear change Lever and preventing the stick from seating properly hopefully I'll get time today or tomorrow. Ifind since retirement I have no time (or money)
Cheers JohnG

John
It is unusual for the first motion shaft not to be stamped with its identifying number.
The shaft number on the 22G172 shaft I have is stamped just forward of the machined surface for the return scroll and may be shrouded by the front housing/cover when assembled. The number is stamped radially around the shaft and not fore and aft and could be easily missed if the number is not conspicuous stamped.
Looking through the spare aperture in the bell housing the number on the shaft will be completely shrouded by the clutch release lever and release bearing (if forward of the front gearbox front housing/cover) so I doubt that you will be able to garner any information that way.
Phil

John,

With the exception of the early Frogeye Sprite, all the other Sprite/Midgets had closer ratios than the Minor/A35/A40 etc., so working out the ratios in your box will tell you if it is from a Sprite/Midget or not.

Is it definitely a 'ribcase' gearbox?

Phil. While I am perfectly willing To accept that my fading eyesight and cognitive power may have caused me to miss the number I'm sure the Sprite man would have known where to look and he couldn't find it either.....
Richard.Well it's got ribs......
I have now got the plastic cup and spring. I have also got " Morris minor shoulder" which you get by lying under cars on cold concrete at 80 years of age. It has been lubed by a doctor with a large needle and I'm not allowed to use it for 6 days. So it will all have to wait. When I can I'll fit the bush having first cleaned out the lever,and check the ratios a s best I can, I'm guessing by comparing rear wheel rotations against prop shaft rotations,? and report back
Cheers JohnG

Hi John

Just a heads up that checking propshaft to wheel rotations, will only give you the ratio of the back axle.

You need to be checking the number of turns of the gearbox input shaft compared to the output at the propshaft, so to do that you will probably need to remove the spark plugs and turn the engine over with the starting handle in each gear. It might be easier with two people to do the counting.

Phil

High time I reported back. I removed the gear stick and found not the nylon cup I expected but a metal cup under which was a metal spring which was broken with the broken off part lying horizontally on top of the remains of the spring in a T formation. I experimented by fitting the nylon cup and new spring which resulted in a hopeless gear change, almost impossible to move and random selection of gears. I decided to put it all back as it was when I got it, I.e metal cup, new spring and curved stick. I was then able to screw the mounting plate down without spacers and was rewarded with a smooth and precise change but still jumping out of third.
I then lifted the floor and removed the side plate to look at the selector balls and springs. One came out with a magnet and looked unremarkable. The other would move only slightly in the bore and then caught, presumably
on a burr? So no progress there as expected. A local elderly mechanic has suggested looking at the plungers on the bottom of the box and that putting a washer under the spring might work but only for a short time. To do this I need to know which of the 2 plungers locks 3rd. Can anyone tell me please?
Ultimately I will have to find somewhere to get the box out
and apart . Many thanks to forum members for their help so far
Cheers John G

For some unknown reason my last post didn't appear in new topics but went straight to mechanical where it has languished since, so I am posting this to see what happens....

Is it a worn selector fork?

Thanks NAT. That is one of the suspect's,but the box has to come out to check. Ithink I can get the rods and forks out without a complete dismantlement,so that is early on the list. Still looking for somewhere to do the work. Ido have a brother in law with a fully equipped workshop and mechanical skills. He lives in the Hunter valley, only 800 odd miles away , a big ask for a minor with only 3 working speeds.......
Cheers JohnG