Matching speedometer to drive chain

[gtt1951]

Hello again,
My 1956 Series II Traveller, in the past, was fitted with a 1098cc engine, matching gearbox and gearbox tunnel, but retained its original diff. The speedometer is, I think, the original and is the same model as the one on the left (photo taken of the current spares holding I acquired in about 1980)[frame][/frame]
The reverse of the speedos is in the next picture[frame][/frame]
Is this the correct speedometer for the SII with Trafficator Only signalling (the IND light doesn't actually light on my Speedo, should it?) and how far out would it be on the road speed indication?
What car would the right-hand speedo have come out of?
As always, thankful for any help (or Scottish put-down), George.

[DAVIDMCCULLOUGH]

The one on the left is the same as I fitted to my 56 series 11 traveller, it also has 1098 engine and box and axle and reads fairly accurately. I did run a wire and bulb holder over from the semaphore switch to place on the speedo for the indicator.

The middle speedo is for a later 948 car and the other is not morris minor, mini perhaps?

[gtt1951]

David, thanks for the reply. The middle one was also the type that I had on my 1964 saloon, which did have a 1098 engine but may have started out with a 948. Gone a long time ago, so cannot check. Looks like I'll have to get the fitted one out to see what is on the back. Picture of the dashboard, also showing the 1098 tunnel and gear-lever[frame][/frame]
The "lump" on the steering wheel is pipe lagging protector for the "security lock clamp".

[mike.perry]

The correct speedo for the diff is identified by the TPM figure on the dial. For an 803/5.375 diff it is 1000.
There is a table of speedos on http://seriesmm.mmoc.org.uk car ident, speedo chart

[gtt1951]

Mike, thanks very much for the link. The speedo actually fitted to my Traveller is the correct 1000 TPM one with serial number 511440109, Bronze face, as fitted to Late Series 2.[frame][/frame]
Referring back to the picture of the three spares, the one on the left is a 1500 TPM, Bronze face and fitted to Series 3 Saloon , Convertable and Traveller, apparently with the same axle ration of 5.375. The middle one is a Bronze face 1504 TPM unit, S/N 4407/00 so would have been fitted to a Traveller with a 4.55 Axle ratio and, the one on the right, is a Silver face 1408 TPM unit, S/N 4410/00 with 4.22 axle ratio and, according to the speedo chart, not fitted to any specific Morris. The black faced 1408 type would have been fitted in a Mini.
Thanks again, George.

[mike.perry]

The TPM 1000 is Series II 5.375 diff, 1504 is 948 4.55 diff and 1408 is 1098 4.22 diff. Other speedos are probably Mini speedos and may be useful for 3.9, 3.7 diffs and non standard wheels/tyres etc

[gtt1951]

Merry Christmas to one and all!
Just before Christmas I replaced the SU carb with a cleaned up (and readjusted one) from my spares - made the engine run very smoothly but, alas, it didn't last long as the old nylon fuel pipe from float chamber to jet, sprung a leak.
I replaced with a new jet assembly and then had to wait until the weather got better to refit the carb.
This I did on Christmas Day (yesterday) and it ran "as sweet as a nut". So well, that I decided to take the car out for a longer road test (which I videoed using my In-Car crash camera).
This has shown up that the speedo (a 1000 TPM one) and the drive chain do not match up, the speedo showing grossly over the true speed. At about 40mph it was showing a wobbly 55mph and at approximately 30mph it was showing just over 40.
It was a lovely drive, however, and did bring a big grin to my face - a real Christmas present!
I was going to re-bleed the brakes today (filled with the silicone fluid), but the weather is now turning again.

[bmcecosse]

A 1248 tpm speedo should put it right then. But only available with a black face.

[mike.perry]

If you still have the original 5.375 diff with with a 1098 engine then the car must be horribly under geared in top. I tried that combination in my van for a short while and was able to accelerate up a 1 in 6 hill in top gear, overtaking other traffic. Fun in hilly country but boring on motorways so I would recommend changing the diff then fitting the correct speedo.
The reason that your speedo is inaccurate is that the 948,1098 and MG1275 boxes all have 5/13 speedo gear to pinion ratio and the 803 box has a 2/9 ratio

[gtt1951]

As far as I know, the diff is the original one for the 803cc engine. When I bought the car, it came with masses of spares, including a complete gearbox, a complete diff for the 1098 engine, front back-plates, drums and shoes in 8" dia, spare (used) front kingpins and trunnions etc. The seller never got around to fitting the correct diff (and uprated brakes).
My plan was to put back an 803 gearbox (which I also have) and the 803 engine (needs thorough overhaul) - this would make the interior correct and would look "right" under the bonnet.
I have a type 1500 speedometer, which I have just stripped, cleaned the face and glass, and reset the odometer to all zeros,
having first "fixed" the ratchet, which wasn't doing it's job.
I note that BMC said to use a 1248 TPM speedo, but I want to keep the correct facia colours and wouldn't a 1500 (from 948 engines) be more accurate than the 1000 with the gearbox I currently have fitted?
When I next go for a road trip, I'll take along my Garmin "personnal navigator" (not SatNav) which is accurate to 16 feet distance as it uses about 6 satellites for triangulation and use its "speed display" function.

[bmcecosse]

Changing to a 1500 tpm speedo will put it wrong the other way. Your figures suggest ~ 25% error so the 1248 speedo is what you need to correct it as things stand at the moment. Only available ex Mini - so black face.

[JOWETTJAVELIN]

I wonder if you could swap the faces over so it'd look right. In theory it would work as it wouldn't affect calibration but you'd have to check the position of the numerals on the face - I believe black ones read to 90 mph? In which case it mightn't work after all.

[mike.perry]

You can fit the back section of an 803 box to a 1098 box so that you would retain the old lever position and you could fit the 1098 diff. You would also need to replace the gearbox floor cover plate and the original gearbox mountings. You could not swap the faces of the speedos because as you say the numerals on the faces do not match. 40 mph on an 80 mph speedo = 45 on a 90mph speedo

[bmcecosse]

Only with some difficulty (ie machining) can the 803 parts be fitted to a 1098 box - straight swap on a 948 box.

[gtt1951]

BMC, How can I tell a 948 gearbox from a 1098 gearbox?
The "spare" that came with the car looks as if it had some "gold Seal" work done on it[frame][/frame]
The side plate has the MOWOG logo. The "spare" 803cc gearbox is on the next image[frame][/frame]
and the one currently fitted to the car (with the 1098 engine in front) looks about the same as the first picture and does have a ribbed case - no picture.

[mike.perry]

Ribbed case = 1098 box, smooth case = 948 box

[gtt1951]

That's a shame Mike, as I won't be able to do what you suggested about bolting the back of the 803 box to the existing gearbox front. I do have the 803 gearbox tunnel, but don't have a crossmember - just the projection with the rubber mounts as per the grainy picture.
I wish it would stop raining, here, so I can take off the covers and go for another drive with the Garmin Geko unit.
Many thanks for all the replies, GEorge.

[JOWETTJAVELIN]

I think Mike is referring to the remote control so you can keep the long gear stick.

[bmcecosse]

Indeed - and an early 803 tail shaft assembly does not easily fit on a 1098 box.

[IslipMinor]

The 'ribbed' gearbox has the 'baulk ring' synchromesh, which works much better than the earlier plain cone synchro fitted to the 803/948 cars.

The combination of the 1098 gearbox and 5.375 diff ratio means you need a speedo with 1800 tpm (turns per mile), so of the standard heads available, the best would be the 1504 from the 948 engined Minor. It would still over read by 20% though!!

If you refit the 803 engine and gearbox, everything reverts to the correct relationship, and the speedo will read as accurately as it did when originally made.