Axle shaft troubles

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Oct 30, 2010 | 07:59 PM

ilovemy60ford

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Axle shaft troubles

Here's a question that has me stumped!

I bought a 9" rear end with 4.10 gears to put in my 1971 Ford F100 truck. The AOD tranny along with 30" tires and 3.50 gears did not yield a good RPM at highway speeds. I dropped the new carrier in my existing housing, then notice that this required larger axle shafts. The larger axles shafts that came with the new rear end are too long to fit my old housing by somewhere around 2.5" per axle.

Is there a stock axle that will fit this application? I measure 29"+, not quite 30".
I don't think that these stock axles can be shortened...am I correct?
Any ingenious ideas to get this resolved well for cheap are welcome! My budget is just about dry as usual.

I may be forced to just swap the whole assembly for now. I'll bet that would look GREAT.

Oct 31, 2010 | 01:14 AM

NumberDummy

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There were two different 9" rear axles used in 1968/72 F100's:

C8TZ4234A .. 9" Axleshaft-28 spline / Measures 29 15/16" long from inside the flange to the splined end / 1968/72 F100.

C8TZ4234B .. 9" Axleshaft-31 spline / Measures 29 13/16" long from inside the flange to the splined end / 1968/72 F100 with Traction-Lok and a 9 3/8" ring gear.

Ford increased the distance between the rear frame rails beginning in 1973 to 37 1/2 inches. Prior years, it was 33 1/2 inches.

The 1973/86 axleshafts vary in length, as there were different applications and spline counts. For example, the 1973/79 9" 31 spline axleshaft (D6TZ4234A) measures 31 51/64" from inside the flange to the splined end.

Why not just swap the ring and pinion? The 4.11-1 R&P is the same 1957/86....fits all except the 9" w/the 9 3/8" ring gear.

Oct 31, 2010 | 09:26 AM

ilovemy60ford

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Honestly, I don't know how to swap the gears. But it does sound like a good option. I hadn't thought of that. I may look into that! Thanks NumberDummy.

Oct 31, 2010 | 08:00 PM

4x4jedi

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Swapping gears in a 9in is as easy as gears get. I havnt done it myself but have done danas and Toyota. I'm shure if you started up a new thread you could get step by step directions no problem.

Mar 29, 2011 | 03:05 PM

mrjodoco

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I have a 1927 ford f100.
Broken rear L axle.
I have purchased a 68-72 axle on ebay It doesn't fit. Seller tells me it is a 68 - 72 axle, mechanic tells me not. Difference is the measurement form the spline end to bearing retainer. Mine is 26 4/16. Seller is 26 11/16, so when axle is placed in the sleeve it doesn't bolt up rcorrectly to hub. Also the flange is different. MIne is a simple rectangle 4 hole in the 4 corners 4.5 x 3 3/4, seller's flange has "oil" drip curves and is my huse shaped.
28 spline on both of them, overall length is the same.

I have photos if i helps?
any help?

Mar 29, 2011 | 03:32 PM

NumberDummy

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From: Simi Valley, CA

Quote:

Originally Posted by NumberDummy

Quote:

Originally Posted by mrjodoco

I have purchased a 1968-72 axle from ebay.

If neither of the above is correct, it's not from any 1968/72 F100. It could be from a Bronco or Passenger Car, or for another year truck.

1957/67 F100 is the same (B7TZ-4234-A 29 11/16" long). 1973/86 F100/150: There's a gazillion different ones.

Measure the axle the way I typed above...measuring it to the bearing retainer...which is not part of the axle (sold by itself originally)....means I won't have a clue as to what it's from.

1974/79: Some 9" axles use a bearing/seal combination. Otherwise 1957/87, the seal is separate from the bearing.

btw: You might ask the ebay seller (many haven't a single clue what the parts come from) what size the rear brake shoes are on that supposed 1968/72 F100.