I have a chance to acquire a 9" rear from what I was told was a 1966 Ford F100. I know no other information on the donor.

I hope that some people here can help me out, perhaps confirming some information as well...

What I have been able to research is that it is 61 3/4 inches wide (which will work for my application).

The gearing is 3.04 (which I would be changing anyway).

What I have not been able to confirm/deny is the bearing size and spline count on the shafts. I am kind of thinking it is a 28 spline, but would someone here know for sure? How about big/small bearing?

I tried to search for some information (here and google), but couldn't seem to find the answers I am looking for.

Any help would be appreciated. Any other infor you think I should know would help as well.

I would be cuting off the spring perches and welding on some other ones anyway, so information in that regard (measurements and such) wouldn't be needed.

Thanks
Chris

 

There is no way to know for sure without pulling the chunk, or punkin, or third member as it is variably called.
MOST likely, it is 28 spline, and MOST likely, it is small bearing.
That is assuming it is original to the truck as well, which is usually the case as well.
Sorry I cannot be of more help.

 

I know that I cannoot find out for sure until I have it to check the third member. I am kinda fishing for some trends, or most likely scenarios.

I kinda assume it is a 28 spline, small bearing thoguh.

Thanks for your answer and any others that chime in.

 

If V8 it's most likely a bottom rung, entry level, 9" -28 spline, open "legged", small bearing, bare minimum, which is both the common rear axle than, and still a lot better than most other rears by other OEMs. But if it is a 240 CID I-6 it could be a Dana 40, which IMHO isn't worth trouble of taking out to install in another "Slick".

If rear has a back cover plate, that unbolts for access to differential, it's a Dana.
On the other hand if a 9" it will be a front loading centersection and pinion housing will distend down so deep socket & extension can't be used to remove botom bolts holding center section in axle housing.

Ratio will be determined by engine type, transmission, & sometimes Build site or DSO. If you are not sure what rear axle assy it is don't pay for it until you are sure. A lot of people have been "stuck" buying stuff they aren't really certain of, ya know?

If you determine it to be 9" you have a good price on it, you can't get hurt unless it needs major attention/ work, or rebuilding. . . . Some people do run their rear ends dry & ruin them. Others have been known to ride around with faulty rear axle bearings and ruin them, and some people actually manage to break them in various ways.

SO check thrice and pay once.
FBp

 

If I can find a 9" differential pinion ((4/11?)) does anyone know how much space (or play) is used for the differential and pinion?
Also know how a press may be used to get the pinion off to replace the seal?

 

Ford didn't offer a 3.04-1 ratio in anything.

The cars from this era mostly had 3.00-1's. The trucks highest (lowest numerically) rear end was 3.25-1 as original.

All 1957/67 Ford 9 inch F Series axleshafts are 28 spline (and are the same R/L). Most 1968/72 rear axles are 28 spline, but 31 splined axles were optional beginning in 1968.

You don't have to remove the pinion gear to replace a pinion seal. You'll do yourself a great service if you buy a shop manual.

 

ok seal no problem... is there any space between the differential and pinion gear... if so how much?

 

ok seal no problem... is there any space between the differential (ring )and pinion gear... if so how much?