Quote Originally Posted by pfillery View Post
Done, successfully I hope.

Only thing is I can't find any indication of which ( SWB/LWB )vehicle the new speedo is for - I have heard that they were different. Mine in the car has 1408 on it near the bottom, which I recall is the one for LWB with the 7.50 x 16 tyres. But the new one has no numbers on the front, just "made in England" at the bottom. There is a paper label on the casing which has SNT6209-32 on it, but thats it. The speedos are both mph/kph with trip, and the replacement unit came from a lwb vehicle, so hoping its right, but theres no point fitting the wrong one.

How far out will the speeds be if the wrong speedo is fitted?
The lwb speedo is designed for 7.50 tyres, i.e. nominal 31" diameter, and the swb fro 6.00 tyres, i.e. nominal 28" diameter. So using the wrong speedo for the tyre size will give an error of approximately 10%, with the actual speed exceeding the speedo reading if you use a swb speedo with 7.50 tyres and vice versa if you use a lwb speedo with 6.00 tyres.

You can compare the ratio of your new speedo with your old one by counting the turns (with a screwdriver) to increment one kilometer (or 1/10th if both have a trip odometer). Might take a while - I think the 1408 figure is the turns per kilometer!

John