Technical What Franklin element should I use?

What Franklin rear end “element” do I need for this rear end? This was a spare truck rear end I purchased that I think came from a NASCAR team selling their old junk. It was never run. It is going into a 1929 Model A roadster build. The frame is newly build and will be part of a drivetrain including a Navarro supercharged 59AB flathead through a T-5 xmission. Let me know and thanks.

 

What elements are you referring to? It looks fine just as it is to me. Here’s my almost identical Winters rear. I like yours the way it is. I am ***uming it has a differential and not a spool…

 

Gears inside of the rear cover? A differential instead of a spool?
The only other stuff I see missing in the picture are brakes, shocks, and a driveshaft. None of which need to be from Franklin.

 

Element as in
Oiler / pump & filter ?

 

There are no gears that couple the driveshaft to the axles.

 

I am ***uming that you are referring to the change gears behind the rear cover? If so, first find out the ring and pinion ratio. One set of change gears can provide two ratios depending on how you install the gears. Typically the sets are numbered. But the overall gear ratio you end up with depends on with what ring & pinion ratio you match them with. Typical r&p ratios are between 4.11 and 4.86. The numbered change gear sets typically have a chart showing the overall ratio with a given r&p ratio saving you doing the math. If you are talking about having no ring & pinion set installed that's a different conversation but the above will still apply at some point.

 

A big ol huh? What is an “element”? I’m not understanding your term.

 

I think he means there is no differential and ring and pinion. It looks like the lower shaft is in place since the driveshaft yoke is attached.

 

What number splines are used for the quick change gears?

 

They would be 10 spline.

You just need to look up an online gear calculator that will either give you numbers in the quarter or eighth mile based on hp, weight, and tire diameter, etc and go from there.

Or if it's just a street car, then pick an RPM/MPH calculator for the revs you want to run at the highway speed you want to go with the tire diameter you have. Then pick the spur gears from one of many online charts available to pick the ratio you need.

-rick

 

What are the axles, double spline with drive flanges or 9” Ford style flanged?

Also what is the bolt pattern?

The most common oval track patterns are Wide 5 , 5 on 5 1/2, and 5 on 5

Some do run the “new” 5 on 4.5” Ford and a few run the Chevrolet 5 on 4.75”