I need help decoding a couple codes on my '81 F100 2WD:

Axle Code "07"

Transmission Code "B"

Axle tag is missing and am trying to find the right speedo gear. Transmission says Borg-Warner, but is it a T10, T18, T19, etc??? It is a 4-speed (granny being 1st) and has the 4.9 (300) engine. I'm pretty sure it is all original. I searched the threads on here and couldn't find info for the 1980-86 F100s???

THANKS!

 

The chart I have shows the 07 code for 81 as a 2800lb capacity 9", with a 2.47 ratio.

If the trans is a B/W & original, it will be a T18.
T19's were 460 & diesel......... & T10's weren't factory-installed in the 80-86 trucks.

 

Thank You for the axle info! The trans is a B/W......not 100% sure it is original. Just want to make sure a "B" transmission code meansT18 in 1981, right?

 

I'm not sure on the trans - I had those codes but, with a computer melt-down, lost a lot of info.
I'm sure someone else will be able to provide it.

 

1880/89 Trans Code B is a Clark 4 spd OD

If yours is a BW then somebody put that in there.

 

Understandable swap.
With an OD trans, a 2.47 axle would have been pretty limiting.

 

I wondered why this truck (out of my many 80-86 f-series pickups) does so well on the freeway......80 mph with no problem! It also does very well taking off in 2nd gear. I'm sure it would have been easier to change the rear end gearing??? It does say Borg-Warner on the side, and it is a 4-speed (w/granny first)...........is there a way to ID the transmission? Casting numbers on the side???

THANKS!

 

The Borg-Warner T18 & T19 Transmissions - Novak Conversions

Domestic Truck Tranny Guide

 

While changing the rear gear ratio may seem to be easier, the 4OD trans was not that great. Many failures have occurred with this trans, and the most common "cure" was swapping to the granny 4. Partly because they were much easier to find in a salvage yard in a useable condition.

As for the speedo gear, the exact trans model is not really needed to be known. Ford made it pretty simple. Most standard trans had the speedo cable located on the same side, and autos were typically on the other side. This means simply knowing which side the gear goes on, and the number of teeth needed, results is determining which speedo gear is needed.

Does the speedo work, but read high or low, or not work at all?

 

The speedo reads low (says 60 when going 70). Just took out a 17-tooth speedo gear and put in a 20-tooth..........haven't test driven yet. My '65 Comet C4 transmission and this BW (??) transmission in my pickup both have the speedo gear on the driver's side and are both the same......that's why I have a few speedo gears! Thanks again for the trans info! I just found the casting numbers and am going to research more on the website ctubutis sent me!