Speedo gears

[laserjock]

Folks,

I'm switching from 4.10's to 3.55's. I have not pulled the speedo gear out yet to look at it but does anyone know off hand what color gear I need to correct the speedo?

Thanks!

 

[crash-harris]

First you'll have to check that driven gear, IIRC also the drive gear in the t-case. What size tires do you have, 235/75r16?
Edit: Stock size is 235/85r16 = 31.73" diameter

I'm going to guess you have a BW1345 t-case, drive gear should be 8 tooth. Guessing the driven gear is a pink 19 tooth. Plenty of calculators out there. I'll update this post with the link to the one I used and a rough estimate on the new driven gear.

Here's a couple of calculators.

http://jimroal.com/drive.htm

http://www.tciauto.com/tc/speedometer-gear-calculator/

I could be wrong at guessing the numbers of teeth. It's been awhile, but I had a light duty '89 F250 with a 302 as a parts truck a long time ago. Stock tires, BW1345 t-case (currently on Bruiser) and 4.10 gears. Speedo driven gear on the VSS was a pink 19 tooth. Out of stock replacement output shaft drive gears I've found for the BW1345 say 8 tooth, but mark one tooth and count yours to be sure. And here's the site that I get speedo driven gears from.

http://www.transmissioncenter.org/Ford_Speedometer_Gears.htm

 

[crash-harris]

^^^ post updated.

 

[F350camper]

+1 on checking out the drive gear. If its the 1356, its more than likely worn and you'll want to replace it anyway. Very simple to replace.
also +1 on this calculator http://jimroal.com/drive.htm