I just made a lucky discovery that I wanted to share with my fellow 40 owners who are running larger 35” tires and who may be needing to replace their speedometer gauge cluster…
I just made the swap to an aftermarket speedo gauge cluster on my ‘79 FJ40 (OE was worn and broken) and as we all know, the only available new gauge replacement options show KMH (not MPH). With my larger 35” tires, I assumed I’d have some tinkering ahead of me to get the speedo actually reading correctly (math and ratios and stuff).
To my wonderful surprise, once I made the swap… I found that due to the larger diameter 35” tires, the numbers on the speedo (supposed to read KMH) actually line up perfectly with what the actual MPH is supposed to be - as confirmed by two separate GPS speedometers.
Couldn’t have been more surprised or delighted by the discovery. The only real ‘quirk’ is that the speedo gauge says KMH instead of MPH. But otherwise, just a small price to pay for the convenience of an accurate speedo while running 35s.
Link to the replacement cluster I swapped…Replacement Speedometer Gauge Cluster
Pic of our 40 and the new cluster (after painting it black) attached for reference.
I just made the swap to an aftermarket speedo gauge cluster on my ‘79 FJ40 (OE was worn and broken) and as we all know, the only available new gauge replacement options show KMH (not MPH). With my larger 35” tires, I assumed I’d have some tinkering ahead of me to get the speedo actually reading correctly (math and ratios and stuff).
To my wonderful surprise, once I made the swap… I found that due to the larger diameter 35” tires, the numbers on the speedo (supposed to read KMH) actually line up perfectly with what the actual MPH is supposed to be - as confirmed by two separate GPS speedometers.
Couldn’t have been more surprised or delighted by the discovery. The only real ‘quirk’ is that the speedo gauge says KMH instead of MPH. But otherwise, just a small price to pay for the convenience of an accurate speedo while running 35s.
Link to the replacement cluster I swapped…Replacement Speedometer Gauge Cluster
Pic of our 40 and the new cluster (after painting it black) attached for reference.
