300Tdi speedo calibration

[travelrover]

Hi all

The speedo on my 300Tdi is reading way out and for sometime I have been considering options to calibrate things. Below is roughly what is indicated on the speedo against what (two) GPS's are telling me. The indicated speed is not quite as linear as depicted but i have rounded the figures a little (only a km or two) for ease of use.

Indicated GPS


55 - 50
65 - 60
75 - 70
85 - 80
100 - 90

it is now running 235/85R16's, which I understand are the same diameter as the original 7.50x16's (is this correct?). It had 255/75R16's when I acquired it.

My research suggests correction is a matter of replacing the speedometer drive gear as in this diagram

Rear Flange - Find Land Rover parts at LR Workshop (https://www.lrworkshop.com/diagrams/land-rover-defender-transfer-box/transfer-box-lt230/rear-flange_53758#16)


There are four different options of gears available;

FRC3310 20 teeth blue
FRC3311 21 teeth green
FRC3312 22 teeth yellow
FRC3313 23 teeth red

Blue seems to be the correct one for this tyre size, and I suspect this is the standard factory fit!

Anyone had any experience with this and how did you resolve it?

[manic]

VDO vision Speedo. Looks OEM. Programmable

YBE100530 transducer for pickup

That way if you change tyre size you can just reprogram the Speedo.

Quite simple to do. Press button on Speedo to start calibration. Drive one km (measure with gps) and press it again. Accurate speed on any tyre size or ratio!

[travelrover]

Thanks manic

The 300Tdi is a mechanical speedo so not sure this option will work.

Also seems pretty expensive compared to swapping the drive gear $70 v $500+

[manic]

YBE100530 is a straight swap for the mechanical pick up on the lt230. Used on TD5 up. Just run the wires up to dash and ditch the mech.

True on cost. But perhaps some time saved in future if you change tyre size again. Never $500, can get them new for around $200-$250.

I have a blue gear here , never gonna use it.... PM if you want it posted.









https://uploads.tapatalk-cdn.com/20191215/e616cca610f2cef36c97e788e4b8f244.jpg

[mrb505]

I had the same readings about 10% out, replaced the blue cog with a yellow one now it reads true 130 300tdi 235/85/16 tyres

[Red90]

Check your odometer first. A lot of times it is a zero offset on the speedo and a drive gear change is not the best idea.

The VDO is much much better. The stock Lucas gauges are horrible.

[travelrover]

Check your odometer first. A lot of times it is a zero offset on the speedo and a drive gear change is not the best idea.

The VDO is much much better. I’m not sure where you are coming up with that high price. They are $180. The stock Lucas gauges are horrible.

Thanks red90. I just did a quick google and eBay search to come up with the $$, but that included a transducer.

[mrb505]

The yellow cog fixed my odo as well pretty much spot on now according to the southbound Tamworth 5km distance check
The only problem now is I sit on 90kmh and get 10% worse fuel consumption
Cog was about $30 from memory

[travelrover]

Hi Mrb505

That’s good, yeah I had thought about fuel consumption and figured it wouldn’t be a great result on that front!

Cheers - Simon

[rover-56]

As others have posted, gear frc3312 yellow - 22teeth is the one.
My 130 with 235 tyres is now spot on. Odometer now reads 3% low now though.
Terry

[Rick]

Can this gear be replaced with the box in place?

[travelrover]

Can this gear be replaced with the box in place?

Others will know for sure but it seems to be able to.

[rover-56]

Can this gear be replaced with the box in place?

Yes, easy.
Disconnect the cable from the GB, remove 1 screw, on mine it's an allen hex, the gear and support bearing just pull out.
Terry

[travelrover]

YBE100530 is a straight swap for the mechanical pick up on the lt230. Used on TD5 up.

I have a blue gear here , never gonna use it.... PM if you want it posted.



Hi manic

Tried sending you a PM but it appears your in-box is full and not receiving mail.

I have received the gear. How would you like payment and how much?

Cheers - Simon