Originally Posted by whyholdback
You guys are forgetting about the OD. I didn't bother figuring out the actual gear because the OP indicated a definite lack of interest.
Figuring 2.41 is close, because a 3.42:1 axle with the 700R-4s 0.70:1 OD gives 2.38:1
In which case, the correct speedometer gears are a 17-tooth drive gear, and a 44 tooth driven gear.
Thanks, whyholdback for your interest.
Yeah it looks like cobalt327 forgot about the 700R4 with the .70 overdrive. I actually read his post as 3.41.
. My bad
. Yeah. it would be nice to know the actual ratio, because I am always asked that along with the other usual questions. IE: eng., trans., cam,. So considering that the tire height is 26" (just measured) and the engine runs about 2100 rpm @ 70 mph., what do you suppose my rear axle ratio is ? 3.42:1 ? BTW, I am running a 39 tooth driven gear against a 15 tooth drive gear (if I remember correctly) and the speedo still runs slow. Not really wanting to change speedo drive gears, as they are not cheap. But as I mentioned, the speedo is electronic and programmable, but is close enough for me. I know how much it is off, so I drive accordingly. I did program the speedo when I had the TH350, and if I remember right, you can't get it exact anyway. Did you know that as tires wear, distances from point A to point B increase ?
I used to have to keep records of my mileage for tax purposes at my last job. I used to set my trip meter in my driveway and reset at the mine entrance. As tires wore down, the trip distance would change from 32.6 min with new tires to 33.1 with worn.