Gearbox product codes

[Sam Christie]

Trevor I understand. I have the same gearbox (more or less) and access is a problem now that it is under carpet. I managed to get a look at where the number should be at the front of the box but it either isn't there or is hidden under the paint. The speedo ratio is even more difficult to get at and I hope nobody asks me for it. I have the impression the speedo ratio is probably 4/14 but I think the product code is the crucial number and it does not change with the speedometer ratio.



Ian, thanks for this interesting thread.

I still have hopes that the owner of an M-type with an original MG 4-speed gearbox will come up with the correct product code and I will also try to confirm the D-type product code.

[Ian Grace]

Ted Hack is probably your best bet for D info.

[Sam Christie]

I am keeping Ted up to date with research. Apparently the very complete D-type chassis files show that some surviving D-types started out with MG 4-speed gearboxes.Ted is checking to see if any of the gearboxes have survived.

[Ian Grace]

Hope he's successful.

I feel a really good Tech Topics article emerging here for the spring mag.

By the way, did you see that amazingly original D Type that has just turned up in India?

[Sam Christie]

The D in India looks very good.I would love to see more pictures.I wonder if it has a 3 or 4-speeed gearbox. Ian, I was forgetting you have a special interest in D-types.

In the 4-speed gearbox context I have five very basic questions -

1 Were any 4-speed gearbox model numbers originally seen on Minors other than '74' and '110' ?

2 Which Minors were built with the 4-speed marked '74' at some stage? Was it all Minors except the £100 model ?

3 Which Minors were factory fitted with the '110' gearbox ?

4 Was the '74' or '110' used on any Morris vehicles other than the Minor?

5 Did any Morris cars other than the Minor use a gearbox of the same type but a different number?

[Ian Grace]

Sam,

That gives us a definitive target to shoot at. And this thread seems a good place to gather the requisite data.

I have a question which you might be able to answer straight away. For cars that were fitted with remotes as standard, were their gear box internals reversed to compensate for the reversal that the remote causes?

[ian judd]

Re: the gearchange selection, the remote does not reverse the selection. It's exactly the same as a tower. The different selection (Wolseley and MG), is purely due to a different arrangement inside of the selector mechanism. Wolseley boxes for fitting in Wolseley cars had a reversed selection even when using a tower rather than a remote. All the bits are pretty much interchangable.

Am I right in thinking that the 110 gearbox is the synchromesh one. ( September 1933 on) And that 74 is the constant mesh (September 1932)

[Ian Grace]

Regarding introduction dates and chassis for the 1933 and 1934 seasons.

Morris started producing 2-seater Minors to the 1933 specification as early as 9.6.32 (chassis SV18457), wile the other 1933 season models weren't introduced until SV20301 in August.

1934 models were introduced with chassis SV33779, although this was immediately preceded by a batch 50 GPO vans built to the 1934 specification starting with chassis SV33729.

So, as far as we can tell from the Progress Books, the 4-speed crash box was introduced on Minors at chassis SV18457 on 9.6.32, and the 4-speed synchro box was introduces with chassis SV33729 roughly (I don't have the exact date yet) in mid August 1933.

[Sam Christie]

This has taken a lot of time and thought but I think I have it, more or less. It is not as complex as I make it sound. Forgive me if you already know the following or know better. This is only my opinion and not established fact….

I believe the problem is that the numbers which we see stamped on gearboxes (below the line at the front) are not gearbox model numbers at all !

The number '74' below shows that the gearbox was fitted to a Morris Minor. If precisely the same gearbox had been fitted to a Wolseley or an MG the number would have been different.This is not a serial number but relates either to an engine model number or possibly a car model number - this detail needs more research.



My theory is that the William Morris group introduced a numbering system over their entire private car range for engines in late 1931. Wolseley folk call them 'sanction numbers' and the MG Triple-M Register calls them 'Model codes' . The number '74' for example should only appear on a gearbox fitted new to a Minor in the Morris factory (perhaps someone can clarify if the OHC Minor and SV Minor shared this gearbox as a factory fitting).I believe the numbers were issued in chronological order starting at '50' with the updated Wolseley Hornet in September 1931.I believe this system probably finished with a 'major shake-up' in the Group soon after the introduction of the MG PB.

Because the number stamped on the gearbox is mostly seen on Wolseley made gearboxes I assumed it was specifically a Wolseley gearbox number, but from the MG register I have inferred that the model number was based on the engine (or possibly the car model) and stamped on the gearbox regardless of who made it. So the same numbering system would/should apply to an ENV gearbox regardless.

Here is 'my' integrated list as it stands so far. I have left a space on the right for dates when these numbers first appeared and in order to make the list fit on an A4 page I have left out the unknown numbers.We have 43 known number codes out of roughly a possible 150.



There is only one number clash and to me this suggests a mistake. I believe the Triple-M Register has attributed the model number '65' to the MG C-type incorrectly. Here is a C-type gearbox image which I have taken the liberty of copying from Barry Foster's article on Triple M gearboxes - do you see '65' or '654' or possibly '6 54' ? Do you interpret what you see as '65' ?



In the chronology '54' is spot on (D & C developed at much the same time). '65' did not appear on a Wolseley till June 1932 which seems to me make more sense. Why would MG have gone outside the system and allocated '65' to the C-type? I have asked Robin Hamblett (Triple-M Registrar) about this but from his email I am not sure if he understands the question and he cannot help.

The list above would run to 150 lines if the blanks were included. I can only guess the blanks are mostly other Morris cars but this needs more research.In fact the whole list is entirely open to improvement. Because of the access needed to cross check all the details every step towards improving the list is an uphill battle.

[Ian Grace]

Sam,

An impressive piece of research.

In the spreadsheet, should there not be three numbers for Minor boxes, 3-speed, four-speed and four-speed synchro? Or did the numbering system not start before the end if three-speed box production?

Morris used up their surplus three-speed boxes by offering a Hundred Pound two-seater for the 1932 season, which probably ran out some time in early 1933, but if course the boxes would have been manufactured much earlier.

When you're done, could I trouble you for a Tech Topics article for the Magazine?

[Sam Christie]

I am not sure if the 3 speed came into the scope of the numbering system - the list is a work in progress and can be added to or subtracted from as we discover more.

[Ian Grace]

You could be right. I don't remember seeing these numbers on a three-speed box. Mine is installed under the floorboards in my fabric saloon right now, so not sure if I can inspect it without some dismantling/unscrewing.

[ian judd]

I have just dug out a Wolseley gearbox which has been 'Fordized' that I bought just in case I could do something with it. It is stamped 112 which makes it a Nine. As far as I can see, it would have had a different bell-housing and clutch and it has a mounting point underneath.

I recently went to a foundry where they were casting replacement bell-housings. Don't know what they were for or how much they cost but it shows that a 4 speed gearbox with a broken bell-housing is not necessarily a write-off.

It just occurred to me to inspect the splines since I once had a Ford 10 engined Minor which had an MG J2 gearbox. On this the splines had a Ford spline grafted on which made it useless for fitting back in an MG or Morris. However, on this Wolseley box the splines appear unaltered so either a Ford driven plate will fit the Wolseley splines or a Wolseley plate will fit the Ford clutch. Either way, it means the box is still usable with the right bell-housing in a Wolseley or possibly P/N Type MGs.

[Ian Grace]

I'm picking up on this topic and doing some new research. In the course of this work, I have discovered that my McEvoy has a four-speed crash box (no mystery there), and it has the sanction number 74 on it, as expected. That is the sanction number for the Minor 4-speed crash box. But it has the speedometer gear ratio stamped and 3/12 - not the expected 4/17 which I believe (or had believed) was the ratio for all Minor 4-speed non-synchro boxes (the 4-speed synchro box sanction number is 110)

I conferred with Stuart Cooke who has the prototype McEvoy Minor and his car also has the identical box - sanction number 74 and 3/12 speedometer gear ratio.

First, has anyone else got a Minor 4-speed crash box (sanction number 74) with 3/12 speedometer gear ratio?

Second, the prototype McEvoy Minor RC 300 dates from late 1931 (chassis SV7012). The 4-speed crash box wasn't fitted on SV Minors until the 1933 season and the first of the 1933 models was laid down in June 1032, so how is it that the prototype McEvoy ended up with a 4-speed box - even down to the correct sanction number?

I'm just waiting for Sarah Gibson the report the numbers on her McEvoy gearbox and will report back here. Her McEvoy is VK 6158, chassis SV14288, laid down 3rd March 1932, so also pre-dates the start of 4-speed Minor production by at least several months.

Here's my McEvoy box showing the sanction number 74, the serial number 9602 and the speedometer drive gear ratio 3/12:

[Ian Grace]

Toby Sears reports that he has a 3/12 ratio 4-speed box - the only one I have come across not in a McEvoy, the serial number is 9989, so I suspect this may have originally been fitted to a McEvoy.

Here's the other three 3/12 ratio boxes that I know of:

Gearbox serial Chassis No. McEvoy
78?5 SV7012 RC 300
8387 SV14288 VK 6158
9602 SV31897 NV 2803

My McEvoy is the last one - SV31897, so if gearbox 9989 was fitted to a McEvoy, we'd be looking at a chassis number perhaps around SV34000? A 1933 season McEvoy.

There is a fourth original McEvoy (also a 1933 season car), with chassis SV31850 in Belgium. I have asked the owner for the numbers on the gearbox.

The question is - where are all the other sanction number 74 4-speed boxes in this sequence? The first two cars in the table above were produced before the start of 1933 season SV Minor production. And all 1932 season cars had 3-speed boxes.

We know that the 1931 season SV Minors all had three-speed boxes, so how come RC 300, with chassis SV7012 had a gearbox with serial around 7,800? Even if they all had 4-speed sanction 74 boxes - which they didn't.

The other oddity is that, looking at the table above, the span of serial numbers is about 1,800, while the span of chassis is around 25,000.

And then we have the added problem that the first two of the above McEvoys were built before the introduction of 4-speed boxes in the Minor production (June 1932) - regardless of speedo gear ratio!

Something is definitely not right here, but I'm damned if I know what!

Does anyone else have a 4-speed Minor gearbox stamped with 3/12 speedometer gear ratio?