41 Ford F15a CMP

[Bob Carriere]

Just to expand a bit on other replies - F15A came with 16" wheels and 6/39 toothed diff (6.5:1 ratio), while the 3 tonner Fords (F60S and F60L) came with 20" wheels and 6/43 toothed diff (7.16:1 ratio). Ditto for Chev series - as Bob says the axles were designed to be interchangeable.

The MB C2 shows a ratio of 6.5 and the GM Major Assembly manual shows ratio as 6:39......... and 6:39 is what is usually stamped on the outside of the gear cluster and I remember now that this was previously discussed on the MLU at the "Tooth" count on the ring gear.

Bob

[Tony Wheeler]

Originally Posted by Bob Carriere

and 6:39 is what is usually stamped on the outside of the gear cluster

You've just reminded me Bob - the diff ratio on Fords is stamped on the outside of the housing, adjacent to the filler plug, so it should be a simple matter for Rob to confirm. Here's a few examples on my own Fords, and a stores tag I found wired to a Ford diff housing recently. Presumably a replacement axle assembly - rather important to choose the correct ratio!

[Bob Carriere]

Here is the stamping from a Chev 15CWT.

Bob

[Kootenay Cruiser]

Thanks for the info guys, I'm going to replace the rear crossmember with a piece of 4" square tube and then mount a 10000 lbs winch in front of that with the fair lead bolted to the top of the tube