Ke55 diff gears

[79rolla]

Hey everyone. I am just wanting to know how much the diff gears may make a difference to the speed that the speedo is showing vs the car is actually going. The only thing that I have done is change it from a 3 speed auto to a 5 speed manual. The car still has the 4:30 gears in it. And with those gears from about 60km/h up the speedo is out. At about 100 by phone, the speedo sits between 110-115 km/h. But at 60km/h the car is doing 60km/h by phone. So I'm wondering will 4:11 gears fix this problem or make it worse?

Cheers 79rolla 

 

Edited 18 hours ago by 79rolla

[altezzaclub]

If the boxes had a different final drive it would be a constant ratio out, like 6kph at 60 and 10kph at 100, so if its varying I reckon the speedo might be dodgy. You could pull the instrument cluster out and take the speedo apart to put some light oil on the shaft and bearing in there, they are driven by a magnet working against a tiny copper spiral coil spring. Have the cable out at the same time and hang it up somewhere so you can drip engine oil into it every time you walk past, until it comes out the bottom. Also a good idea with that clutch cable you've just fitted!

Same with the diffs, they would be a constant percentage out. They will change the speedo by 5%, as will tyre size and going to 14" rims, but in theory its all constant. I've run a  3.9, a 4.1 and it came with a 4.3 like yours, originally an auto car. Jap cars were well-known for their speedo over-reads, along with their pony-power figures.