Tachograph Fitting Information

I have been asked a few times recently the best way to fit a tacho. Firstly Chris Dobbings on his own ROOF site has put a good description including part numbers of how he fitted a tachograph to one of his vehicles so it’s always worth looking there which will give you good information.

On my vehicles I always try to get hold of the old type tacho heads which I get from Midland Truck Breakers, they always have stuff for sale on ebay, from memory we pay about £100 per tacho head. I tend to use the same ones which are Lucas Kienzle Automatic although there are other makes and models available I try to keep to the same if possible.

There are two ways to drive your tacho, for instance on a refurb RML there is a device that takes the signal from the original speedo which is still in place and converts the signal so the tacho can read it, the part number of this device is SAISL205, approximate price £100. This is using the signal from the original sender coming through the 551 unit, if you ever need the original sender for the refurb RML type its available from Logitech Electronics, 12 Trench Road, Trench, Telford TF2 7DP. Phone – 01952 677416, the part number is MPU 1702/24. When fitted set the gap between 40 and 60 thou. The price of the part is approximately £70.

The other system which in my opinion is probably the most straight forward, and this one would apply to you Sam, is by a sensor which is situated by the back of the gearbox which picks up on the propshaft bolts and works completely independently to anything else that may or may not be fitted. This is the option I went for on 1357 as the original speedo didn’t work so we actually fitted the tacho where the original speedo was fitted however this can be swapped back and the original dash put in place if the vehicle was ever sold so a preservationist. The sender part number is WEDTAC25RWR and is called a 25ml sender without ring, I appreciate these part numbers would not mean a thing to anybody however a tacho specialist should recognise them, the cost of this sender is about £78. To go with this sender they use WEDTACO1 which is 6ml encrypted cable which is approximately £100.

My bus number (if any): RML2583 and RM1357