Speedo Drive Ratio

[Guest boggie]

Hi All,

I have recently changed my diff from a 3.6:1 standard sierra to a 3.9:1 LSD from a 2.0 4x4. As expected my speedo is wildly out so I want to sort it. Can anyone tell me if it is the speedo drive in the gearbox or the ratio within the speedo itself that need to be changed.

Cheers all,

Boggie

[Guest Twoscoops]

I am also following the same route.

 

Anyone please tell me if I'm wrong but I would think that the speedo drive pinon in the gearbox just needs changing....only problem is I haven't worked out what to...!!!

 

My friendly mate at Fords has told me there are 3 to choose from each with a different number of teeth on.

 

If you manage to find out please could you let me know....

 

P.S. I assume you have used discs instead of drums on the back, if so how have you managed to shorten the handbrake cable...????

[Guest paul thompson]

There are many places where you can get your speedo re calibrated if you tel them the diff ratio and od of the rear wheels. A colleague of mine has done this several times for his self build due to several diffs he has had to use. His car won't rust either as it is made from marine ply, this really is a self build!

[Guest boggie]

Twoscoops: I shortened the cable by drilling 2x 3mm holes in a short M6 bolt then removed the nipple on the drivers side handbrake cable end, pushed the cable through one of the holes in the bolt and then looped the cable around the actuating lever on the caliper going back through the second hole in the bolt. All I had to do then was tighten up a nut on each side of the bolt to clamp the loop and adjust the cable to suit.

Boggie