Speedo overread

This might be one for JM if he is about.

So as most of you know I changed the t/box for a disco one. It all works nice, but the speedo is out by about 15ish%. So if the speedo reads 85 I am in fact doing 72.

The gear that is currently in is a blue one, and is the smaller fitting.

Mines out by well over 30%,, sending it off in the new year to speedy cables to get it re calibrated,,,

might help with the 'how to change' the speedo gear drive

Difflock :: View topic - transfer box/speedo drive gear

This step by step guide also very clear


http://www.land-rover-blog.co.uk/how-to-replace-the-speedo-drive-gear-on-a-land-rover/


Trying to find what colour drive you need

Think you need a blue one (20 teeth) FRC3310

The yellow one you have as standard has 22 teeth

BUT please check with JM before parting with hard earnt cash!

Station House said:

might help with the 'how to change' the speedo gear drive

Difflock :: View topic - transfer box/speedo drive gear

Trying to find what colour drive you need

Click to expand...

Thanks, I found a chart on here (http://www.landyzone.co.uk/lz/f7/speedo-under-read-20-a-120519.html) which gives all of the colour codes. But I don't know which ones will fit as I don't think they are all compatible as the one I took out of the old t/box didn't fit the new one as it was too big

I'm thinking frc9339 might be the one??

Andy at AW Transmissions (0247 666 5505 / 07983 336802) supllied my disco transfer box mated to an R380 gearbox with the correct speedo gear, but i didn't take any notice of what it was

Really helpful guy and like JM ex LR if you get stuck

james6546 said:

This might be one for JM if he is about.

So as most of you know I changed the t/box for a disco one. It all works nice, but the speedo is out by about 15ish%. So if the speedo reads 85 I am in fact doing 72.

The gear that is currently in is a blue one, and is the smaller fitting.

Click to expand...

its not the transfer box gearing that alters speedo its if you change diff ratio or most commonly change tyre size, blue frc3310 is for def on 7.50 tyres which is the tallest lr do , the other speedo gears are for smaller tyres

jamesmartin said:

its not the transfer box gearing that alters speedo its if you change diff ratio or most commonly change tyre size, blue frc3310 is for def on 7.50 tyres which is the tallest lr do , the other speedo gears are for smaller tyres

Click to expand...

Ok, but isn't that the wrong way? If you put bigger tyres on wouldn't that mean that you were travelling faster than the speedo was saying? I'm confused now!

yes it would , and youve already got it fitted ,so youd need a smaller tyre one

jamesmartin said:

yes it would , and youve already got it fitted ,so youd need a smaller tyre one

Click to expand...

Is that frc9339? If so there is one in the for sale section.

frc9339 is 23 tooth so should be about right ration but is black is transducer fitment so wont accept cable, youd need one of below i may have both so you could try
frc3312 yellow ------ 22
frc3313 red ---------- 24

Hi folks I've had enough of my speedometer over reading and want to sort it out. It's currently reading 17% over so reads 73mph but I'm only doing 62mph. I currently have 31x10.50R16 tires and not sure which speedo drive it currently has cos I'm not beside the vehicle an 89 110 rd.
Can someone please point out which speedo drive I need? I was thinking frc3311 blue 22tooth or frc3310 20tooth?