Gear Box ratios and speeedos

[Matt_H]

I'm trying to work out the history of 90/110 gearboxes and relate that to what I've got.  Firstly how can I tell the ratio of my main gearbox and the ratio of my transfer box?  Secondly what was the general ratio history of these boxes?

I've got a C reg 90, with a later 200 tdi engine in and oversized tyres, the speedo massively under reads but she pulls just fine yet maxes out at around 75-80 (actual speed).  I've therefore no idea what I've got and am tryign to work it out!

Is there anyway to change the speedo drive so that my speedo reads correctly?

Thanks
Matthew

[Budgie]

If you can get the serial numbers on the gearbox & transfer box together with the tyre size and give Ashcrofts a ring then they should be able to send you the correct speedo gear.

For gear ratios then have a look here to identify the gearbox and here for the transfer box.

To work out the overall ratio then try this page from All Four Drive.com.