Outer Limits 4x4 Board

I am doing a rebuild on my HJ61, and will be running 285x75x16 BFG A/T's on 80 series GXL rims. (I have an axle widening kit)

I am after a solution to correct the speedo. I know that with 31x10.5x15's that the speedo reading is approximately 10klms out at 100kph. (real speed is more like 92-95kph)

Does anyone know of a way to make the speedo more accurate? Are all 80 series electronic speedos, and if not is it possible to fit the early drive gears into a H55F 5 speed transfer case?

Other option is speedo re calibration, has anyone looked into this and if possible, is it economically feasible?

thanks in advance,

MB

call marks adaptotors here in melbourne they make a speed correction unit, when ya fin out the price let me know

im running both 35 and 33

Ok, just rang Marks Adaptors and they do make a correction unit for 40,45,55,60,62,75 series cruisers (basically any cruiser with the old cable driven speedo).

It is a unit which bolts/screws inline with the speedo cable at the transfer case end, and comes in 3 pre programed ratios: +10%, +12% and +16.5%, these cost $175.00.

If you need a custom ratio, the cost is $195.00.

Considering the price of speeding tickets nowadays, a cheap investment I think.

They said to use a GPS to sit on 100kph, and then get the speedo reading, and work out the ratio from there that you need.

Best I get my finger out and get it all back together.....

I have a Marks Speedo adaptor on mine. Checked the speed with a GPS and found mine to be out by 20% (35" tyres). Marks did the custom adaptor for me - happy with it.

Have you actually checked to see if your speedo is out. A couple years ago I put mine on a dyno to check how much it was out after fitting 35"s. To my surprise the speedo was reading correctly.

I'm running 285/75/16s on my HJ61 too.

My wiz bang TomTom says 103 when my speedo indicates 100.

Good enough for me !!

Cheers,
Duncan.