87 BII 4X4 Speedometer Gear?

[markinms]

Does anyone know what color speedometer gear was used in an 87 BII 4X4 with the 5sp manual transmission? If not color, how about tooth count?

Thanks for any help!

Mark

 

[adsm08]

The answer you want cannot be calculated with the information you have given. In fact all of the information you have given is irrelevant to the answer you want.

We need to know the number of teeth on the drive gear in the trans (assume 7), your differential gearing, and your tire size.


From the crank damper to the gear nothing can be done to change which gear you need. From the gear to the ground anything that changes size or ratio will make a difference.

 

[markinms]

Thanks for the feedback. I "assumed" most if not all BII 4X4s with manual transmission used the same transmission, transfer case (electric or manual) and rear end (3.73 gears). Probably used the same size tires, but that is not a given. So I figured if someone with a BII 4X4, manual trans could let me know what speedo gear they had, it would help me out.

Here's my current situation:

Original (factory equipped) tire size: P205/75R/15 (27.1")

Current Tire Size: P235/70R/15 (28.0")

Rear end: 3.73

Around 20 yrs ago I changed the gear when I went to a larger tire. Can't find the original gear and misplaced the replacement gear during my engine swap. I'm currently using the gear that came with the donor car and it's way off.

Any help figuring this out is greatly appreciated.

Thanks!

Mark

 

[RonD]

You can go here and plug in that info: http://www.tciauto.com/tc/speedometer-gear-calculator/

DRIVE gear is usually 7 tooth for Ranger/BII, but technically unknown at this time.
So 7 tooth Drive
with 3.73 ratio
And 28" tires
= 18.78 teeth on Driven gear so use 19 tooth, 19 tooth's popular color is tan/beige

The smaller the tires the more teeth on driven gear, because you travel less distance per RPM of the tire
The larger the tires the less teeth on driven gear, because you travel more distance per RPM of tire, i.e. 31" tire would use 17 tooth driven gear with your 3.73 ratio