Speedo Swap

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • 79Series
    Low Range
    • Feb 2015
    • 14
    #1

    Speedo Swap

    Would this speedometer work in my 1967 Series IIa with 235/85/16 tires?
    MPH Speedometer for Series III (FF000390) for Land Rover Series IIA/III
    http://www.famousfour.co.uk/new_parts/ff_part?part=666
    Famous Four Products are Independent Land Rover Specialists based in Lincolnshire, UK. We provide Genuine and Aftermarket Land Rover Parts and Accessories, Service, Repair and Restoration. Order Online, by email to info@famousfour.co.uk or phone on +44 (0)1507 609444


    Or is there another replacement out there I might use since originals are NLA?
    Jack
    Tags: None
    • warrenperkinson
      Low Range
      • Jan 2014
      • 78
      #2
      Hi Jack,

      You'll need to take care with the speedo cable connector at the back. I've seen a number of variations on the connector - some push in, some screw in. Because my truck is a mish-mash of every series LR out there, I don't know what is what any more (mine's a sIIa and has a screw in connector). There are also some variations on the trip meter reset cable too.

      I'm pretty sure that there is a subtle difference between the IIa and III as far as the connector at the back of the speedo goes.

      I swapped mine out with a second hand one - but I had to buy about 3 speedos before I was able to cobble one together with the right tyre size compatibility and connector that actually worked! (But that said, it still worked out way cheaper than buying a new one).

      Cheers,
      Warren.
      '71 Series IIa "Horace"
      88", RHD, 2.25 petrol.
      New Zealand.

        Comment

        • SafeAirOne
          Overdrive
          • Apr 2008
          • 3435
          #3
          The SIII speedo has a push-on connection for the speedo cable. Converting is simply a matter of getting the correct style cable for the speedo in use.

          The trick is to get a speedo that will read correctly for the tire size. The number of turns-per-mile for the particular speedometer is printed on the speedometer face.

          A 235/85R16 tire is approximately a 31.5" diameter tire so that's...um...31.5 x pi = 98.96" of travel per revolution of the wheel.

          So that's...63360 inches per mile divided by 98.96" per rev = 640 revs of the rear WHEEL per mile so...

          With a speedometer cable that turns 2.136 times for each revolution of the rear wheel, then the speedo cable will turn...640 x 2.136 = 1367 turns per mile.

          You'll need a 1367 TPM speedometer to be very accurate with those tires, however, the choices in Rover speedos are generally as follows:

          1500>1536 are for swb landrovers on 600 or 650 tyres
          1408 is for 750 tyres
          1344 is for 900's
          --Mark

          1973 SIII 109 RHD 2.5NA Diesel

          0-54mph in just under 11.5 minutes
          (9.7 minutes now that she's a 3-door).

            Comment

            • 79Series
              Low Range
              • Feb 2015
              • 14
              #4
              Great info. Thanks for your responses.
              Jack

                Comment

                Previous template Next
                Working...