36 Pickup Turtle
 

i have 7;50 16 tires on my pickup. there where 6;50 16 on it before. the speedo was close to being accurate, now it is not. i also have a turtle from a model a ford. it is from a 3:78 rear, could i swap them out, to get it closer, will the model a turtle bolt up?

Re: 36 Pickup Turtle
 

Which turtle do you now have on the truck?

Re: 36 Pickup Turtle
 

The tire circumference changed. Housings might interchange but each one is a bit different due to the circumference of the gears and different shafts. Speedo cable connections are different shape on the model A ones depending on year of manufacture. They are numbered for the size of the gear. You need to find the number housing you need according to the chart in the green bible. I'm pretty sure that new gears are available.

Re: 36 Pickup Turtle
 

its the orignal one, 1936

Re: 36 Pickup Turtle
 

That's the year, but that has nothing to do with the ratio. What you need to know is part number of the housing and the number of gear teeth it has. It will depend on the original rear axle ratio and tire size (assuming everything is factory original). The base number is 17270.

Re: 36 Pickup Turtle
 

Brendan......Even though the one you have is ORIGINAL, the "turtles" were made (and NUMBERED) to correspond with the gear RATIO found in a particular vehicle. The number you see embossed on the turtle below (18) represents the number of TEETH on that turtle's gear. In the case below, 18-teeth was the number that corresponded to a 3.54 rear end along with standard-issue tire size. So, what we need to know is the EMBOSSED NUMBER on your "original" turtle before any recommendations can be made. DD

https://www.fordbarn.com/forum/attac...8&d=1472614622