Vintage Minor Register

Your Questions and Answers

Minor Saloon Door Trim


I am trying to find out specification of the original door trim for my coachbuilt saloon.  As photos on the site show, the prototype had pockets and a strip of carpet along the bottom, but did this go into production, or was it simply a piece of 1/8" ply covered in leathercloth like the rest of the car?  I would be grateful for any information. Also, how much of the
floor was carpeted - did it go up under the pedals?
Paul Rogers



These images should help you.  Both are 1931 SV Minor saloons, but the interior trim was identical to that of the OHC saloons.  Remember that production ran in parallel until July 1931, and so the body shop at Cowley built 'generic' Minor saloon bodies which could be fitted to either OHC and SV chassis (depending only upon what colour they were painted).

The colour image was taken about fifteen years ago.  This is Ted Coney's car, shortly after re-trimming in the original style. The black and white image is an original Morris Motors photograph.

With regard to carpets, the 1929 cars had colour matched linoleum tacked to the floorboards (either brown or blue), while all later cars had carpets which covered the floor and footboards and gearbox cover, and through which the pedals protruded.

Minor Differential Setting Up

(Thanks to Lyndon Pope and Bob Grunau for this one)


I have just put my M-Type [same as Minor] diff. in to a specialist to be set up. The chap that's doing the work has noticed that there is some 'end play' in the pinion shaft and he is not sure if it was assembled in the correct order. He says that there are two bearings, a thrust bearing and a carrier bearing for the pinion. He is wondering if they may have been transposed at some time.  Does anyone have any knowledge of the way all of the pinion bits and pieces go together ? Or is the 'end play' normal for these cars. My specialist thinks it will cause problems on deceleration.


Your specialist is absolutely right. There must be no "end play" in the pinion. If there is the front pinion bearing, which takes the thrust, is worn or too loose. End play will very quickly ruin the pinion gear or crown wheel. In addition, there must be no SIDE play at the pinion, this is controlled by the tightness of the straight roller bearing at the rear.  Measurable side play means the roller bearing is worn.

I have set up my J2 differential (same design as M type), using modern tapered roller bearings and when these are slightly pre-loaded the pinion is fixed in position. The tapered roller bearings also have a much greater strength and locate the pinion better than the original roller/ball bearings. Tapered rollers also allow use of some Loctite Bearing Mount (or similar) to be smeared on the outer races before assembly to tighten the fit of the outer races in the bevel pinion housing. The inner races are clamped by the pinion nut when it is torqued up.

Original set-up was single row ball/thrust bearing at the front, spacer, roller bearing at rear next to the pinion gear.

Find out why there is end play and repair the problem. Tapered rollers will certainly be a better long term solution. However use of tapered rollers means a bit more set-up time as the pinion bearings will need to be pre-loaded to about 5-6 lb-inches. Also the pinion location must be accurately set with the tapered rollers in position. I would check the location of the pinion BEFORE stripping the diff. apart, fit the tapered rollers, then set the pinion back to the same location using appropriate shims.   A good description of setting up a tapered roller bearing diff. can be found in Blowers MG Workshop Manual under Rear Axle, 1 1/4 litre Series Y, pages 196/198.

[If anyone needs the Blower reference, contact for a copy]

SU Carburettor Size


I have a 1930 Minor and I am trying to discover the size of SU carb which should be fitted. Presently it has a 7/8" bore one which looks a bit small. I have not been able to find this information in any published material so far !


Yes, all Minors should have the 7/8" carb.  Only the M Type had a 1" carb.  You can fit a 1", but you need to fit it with an M Type manifold (which does actually fit) - otherwise you are wasting your time as the inlet passages in the Minor manifold are 7/8".

Also note than fitting a larger carb. makes your car modified in the eyes of the VSCC and ineligible for Light Car section events.

Below is a picture of an OHV Minor engine with a 1" carb. and M Type manifold fitted. If you look closely, you can see where the cooling fins and MG motif have been ground off!

Speedometer Ratios


I am having trouble with my Minor speedo, which seems to be under-reading.  How can I check it for correct operation, and how can I tell whether I have the right type of speedo fitted – mine is marked “PC”.


The OHC Minor was fitted with a 3” Smiths white-faced PC type speedometer.  The letters on Smiths speedometers (PC, PA, FN, etc) relate to the turns per mile of the speedo cable.  So it doesn't matter what type of PC speedo you have in your Minor (remember, I have an upside down 0-80 PC) - it should read accurately.

Now, if you suspect that your PC speedo is misreading, then you can check what's going on in the following way:

1) Rope in an assistant and have her jack up one rear wheel, and turn the airborne wheel 25 times, while you sit in the car and watch the end of the speedo cable, which you have just removed from the speedo.  Count the number of turns that the cable did.

2) Now you need to know the number of turns that the wheel does in a mile.  You can:

a) Have your assistant remove the jack and push the car along a measured mile (doesn't matter if its uphill), or

b) Confirm that you have 350/400 x 19" tyres on the back of the car, in which case, they will do about 744 turns per mile if they are inflated properly.

3) Now, multiply the number of turns the cable made (for 25 wheel turns) by 8, and then by 744 (the turns per mile for your tyres).  Divide this number by 100, and you should get 2,100 for a PC type speedo, which is the number of turns per mile, and therefore also the turns per minute (or cable RPM), which will make the speedo read 60 mph.

(If you think about it, the 8 comes from 4 times 2 - the four saves you turning the rear wheel 100 times, and the 2 because one rear wheel is on the ground, so the differential will only be doing 12.5 axle turns for every 25 turns of the airborne wheel.  Since you divide the result by 100, the 100's cancel, and you are left with the number of cable turns per wheel turn times the number of wheel turns per mile, which is the number of cable turns per mile, which is what must equal 2,100 for the PC speedo.)

If all is well, you should have counted about 35 cable turns in Step 1 above.

Note that the diff. ratio and the speedo drive gear ratios don't come into the calculation - but if your answer comes out wrong, then check you have a 9/44 diff. and a 4/17 set of speedo drive gears in your gearbox.  Many vintage Minors have been fitted over the years with later, lower ratio, back axles or differentials.  The diff. ratio is stamped on top of the aluminum diff. housing, but beware that someone may have swapped the internals in the past.  To check absolutely, have your assistant jack up one wheel again, remove the diff. cover, mark one tooth and slowly turn the airborne wheel twice, counting the number of crownwheel teeth.  There should be 44.

If you conclude that your speedo is, in fact, being economic with the truth, get in touch with John Marks at Vintage Restorations, who will happily rebuild/recalibrate it for you. 

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