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Smiths Speedo SN numbers
Posted: Wed Oct 22, 2008 8:06 pm
by WPR678B
I know there are a few of you on here that know what the numbers mean on Smiths speedo's so here's one for you!
I have a speedo with the numbers SN 4419/00 and 1472 (which i believe to be the TPM?).
What i was wondering (and hoping for!) is that someone will know what this came from originally?
I fitted the above speedo today to my pick up which is now running a Type 9 5-speed with a 3.9 diff and 175/70x14 tyres (on Minilite rims) and it seems to read pretty accurate!
Any idea's please?
Posted: Wed Oct 22, 2008 11:08 pm
by bmcecosse
I 'think' 1472 tpm number would be with a 4.55 diff. The 4.22 diff car seem to be ~ 1408 tpm (SEE MY EDIT BELOW) . But - it would be good if someone could make a list of all know Speedo tpm, including the Mini variatons !
Do you know if your 5 speed is direct drive in top gear - or is there an 'overdive' gearing in the top gear, and if so - what is it!?
Edit! I've now realised my Speedo (4.22 diff/155 tyres) is 1508 tpm - and this gives VERY good mileage readout (~ 1% high) although the actual speed reading is about 8% high! I suspect the needle spring weakens with age!
Edit edit! It has turned out that my diff was in fact a 4.55 - with the 155 tyres and 1508 speedo it gave the very good mileage reading.
Posted: Thu Oct 23, 2008 3:20 pm
by Matt
Type 9 has overdrive, the ratios depends on the gearset inside, but 4th is always 1:1
Posted: Thu Oct 23, 2008 5:02 pm
by WPR678B
Although the frame is the same as a Minor one (in other words, not a Mini one!) i am pretty sure this was not a standard fit!!!
I was hoping that someone would know what it came from originally from the numbers before i posted a picture

Posted: Sat Oct 25, 2008 2:43 pm
by bmcecosse
Mini and Minor speedos are the same - except for warning light and speed marking details. Not considering the later 'Clubman' type Mini instruments of course which were in a ghastly little binnacle in front of the driver.
Posted: Sat Oct 25, 2008 6:17 pm
by WPR678B
Posted a picture in a new thread in General discussion
