W58 Speedo Drive Gear - 33/9 Any such thing

[takai]

Ok, im having issues trying to mathematically work out why my speedo is out so much, and have started this new thread because my other thread seems to have dribbled into people making inane jokes.

The real question im wondering is about the existance of a 33/9 speedo gear. I didnt think that 9 tooth existed on the drive shaft, but thats what this picture of my speedo gear seems to indicate:


Now from the other thread the car is out by around 10%, or the same as from a 3.9 (3.1:1) to a 4.3 (3.5:1) However, with a 33 tooth speedo gear the drive ratio is only 3.3:1 rather than the 3.5:1 which it seems to be. 33/9 however gives a 3.66:1 ratio, which could explain the discrepancy.

Thoughts? Ideas? Anyone know if there is a 28tooth gearing for that size gear?

[takai]

After much searching on ToyoDiy it seems there is such a thing:


Now to see if i can find a 28 tooth for a 9 drivve gear

[CrUZida]

The 33/9 is for a diff ratio around 4.556 or shorter.

I'm guessing since you want a 28/9 you have a ratio of around 3.9:1

I don't think 28/9 even exists, and if it did it wouldn't mesh with the 9 tooth gear inside the gearbox at the moment.

You are going to have to pull the gbox out/apart and replace it with a 10 tooth gear, and use a 31/10

28/9 = 3.111111
31/10 = 3.1

[takai]

Yup, thats what i was thinking. I didnt even know a 33/9 existed until today though. I know a good home for the 33/9 however.