Thread: Wrong Speedo reading

The Series 1 and 2a transfer case are interchangeable, but in any case the speedo takeoff is at the back of the case and unlike the coil sprung Landrovers, there is only one type of worm and gear takeoff. Over reading grossly like that would be most unusual - 50mph is 80kph! More usual is under reading or erratic readings due to the worm on the output shaft not being secure.

However, you should also be aware that there are two* different speedos, which depend not on the Series, but on the tyre size. Those standard on the short wheelbase are set for 6.00x16 tyres, and those standard on the lwb are set for 7.50x16 tyres - but the larger tyres and hence speedo were optional on the swb 2a. They can be distinguished by the very small numbers at the bottom of the dial, but I don't know the numbers (revolutions per mile or km). And at this length of time since manufacture, heaven knows where the speedo came from!

* There are actually a lot more - trip meter or not, km or miles, warning lights incorporated after 1967, higher maximum speed on sixes etc as well as the ratio set by tyre size.

A changed diff ratio will also change the reading, but such changes are fairly rare for Series 1 and in any case would cause the speedo to under read, not over read.

The only remedy I can think of would be to have the speedo refurbished.

John

As my ser1 runs 7.00x16 tyres, the speedo is smooth when working , not eratic at all, has been fitted for a couple of months now, I did not know they came with different speedos, I thought it was a gearbox/diff ratio change

Here is an old thread on speedo gearing.

The Series Speedo and Tyre Sizes

Colin