Hi I am planning on putting a 9" Ford rear axle in my 41 coupe. I measured the flathead axle and it is 52 inches brake drum backing plate to break drum backing plate . What year/model fords had a 9" axle with that measurement ? Will I have to have one narrowed ? Any info will be greatly appreciated. Thanks Joe
You will need to determine what with you want wheel-mounting-surface to wheel-mounting-surface (wms to wms). Between backing plate offsets, brake offsets, and shoe/drum widths changing over the years/applications, the backing plate measurement is almost useless. Grab a friend, two straight objects, and a tape measure. Measure where the wheels mount, side-to-side. Also, post what bolt pattern you'd like to have on it. EDIT: If 58" is the measurement, and you want 5-on-5-1/2", you want a first-generation (1966-1977) Ford Bronco (U100) axle.
Might get more accurate results if you measure from the wheel mounting surface (drum to drum), since brake width varies depending on what brakes it has. But generally you need a relatively narrow rear, like one of the early ones from a late 50s car, or maybe an early Mustang.
Backing plate to backing plate is not a good way to measure (need to know axle offset and brake shoe/drum width). What you want to measure is wheel mounting surface to wheel mounting surface. Most cases you will want 56-58" depending on tire/rim package. Yes more than likely you will need to have one narrowed or buy one already done. Earl
Joe, One link you can check out about 9" Ford rear ends is kevinstang.com also at bottom of page there's links click on the Mustangs & more & it will give rear end widths. If you do a google search for rear end widths some will give measurements for backing plate to backing plate or (WMS) wheel mounting surface to wheel mounting surface. The 57'-59' 9" rears had the narrowest brakes them 3 years & believe 2" brake offset. You can still get brake parts at Macs from there 49-59' catalog. I believe the brake offsets for the Ford 9" rears is 2" - 2 3/8" - 2 1/2". So if you decide to buy used make sure you get it with backing plates, brakes & axles with it! But 9" rears your looking for are, 57-59' Ford auto 52.25" BP to BP 65-66' Mustang 52.25" BP to BP. And then mid 70's Granada's It can get confusing! Big bearing small bearing, spring Perch widths, 28 or 31 spline axles, brakes, open or posi rear? Do your research, learn about the axle tags info if looking at used, example on tag 3L.50 would be a "locker" with 3.50 gear ratio & if it reads 3.50 it's a "open" with 3.50 gear ratio, but look for the L on the tag if your wanting a posi. Joe I've been thru this with my brothers 55' Ford! He had a 57' Ford 9" in it... On the other hand if you want to buy new call Brydon at Quick Performance out of Ames, Iowa. Or check website, they can do a custom rear or buy the housing/axle package for 65' mustang... Also define what your goals are? How much power? drum or disk brakes? Open or posi? But do it right the first time & be done. Jim... Posted using the Full Custom H.A.M.B. App!
I've used 5 early Bronco 9'' rear ends in 3 '32s, 1 '36 and a '40 Ford. They are 58'' outside to outside of brake drums. The main reasons are they have a 5 1/2'' bolt pattern and they are the right width.
Bronco rear ends aren't easy to find either. The bronco guys want them to save broncos. Have you considered ford 8.8 rear ends. Good gear ratios, available "posi" units, mustang, ranger, explorers are candidates so there's plenty available.
I agree, Explorer 8.8's (95-01') are Heavy duty! 3.25" tubes, disk brakes, 3.73 or if lucky 4.10 Gears, & believe 31 spline axles! 4.5x5 bolt pattern. Plus you can find them for a reasonable cost... On Craigslist or Pick & Pull... Definitely an over engineered piece! Plus you can use rear Explorer disk brakes on 9" rear with new style bearing ends... Jim... Posted using the Full Custom H.A.M.B. App!
I don't want disc brakes and I like old Ford wheels with the 5 1/2'' bolt pattern. The axle flanges on most other rear ends are not big enough for the 5 1/2'' pattern.
Listing of rear end width and donor vehicles. A measurement of the rear in your vehicle mounting flange to mounting flange will help us help you. Do you plan on using stock rims or do you want a rear axle that is any narrower to add rim width? http://www.jalopyjournal.com/forum/threads/ford-9-width-chart.302774/
I really don't think the 66-77 Bronco rear axles are that hard to find but you do have to look a little harder to find them. Production numbers show there were 225,900 built in that 10 year period. I have located 4 in the last few years,yes they are desirable because of the bolt pattern that matches the early ford and are darn near indestructible. HRP
They are big enough on the 8.8. There were early Explorers with drum brakes. The axle flanges on 8.8's have no backing plate access holes, so they can be easily redrilled (disc or drum), even to 5-on-5-1/2".
I'm with you,I prefer the 9" Ford,you don't have to worry about re drilling to fit the early wheels and to me they just look better than the later model rear axles. HRP
IIRC, the 8.8 Ford is a C-Clip axle retainer setup. If you run them on a car with a modified engine, NHRA says you gotta use C Clip eliminators. And I don't know about other brands of rear axle components, but Moser recommends NOT using the C Clip eliminators on the street because curves and corners put a side load on these retainers that they aren't designed for and they will wear out and fail. Couple that to the 8.8 being a "Sailisbury" type that requires a full tear down to change to another ratio ring and pinion vs. a pumpkin change for a 9", and I think it's worth spending some more time looking for a 9" with the correct width and either correct bolt pattern or axle flanges big enough to redrill.
Thanks to HRP's advice I'm on my way home right now after spending $600 for a Ford 9" out of a 76' Bronco. It's the correct width and bolt pattern and a 3.50 gear & factory posi to boot! I couldn't of pieced one together for that.
I was pondering the same question for my '35 Ford Pickup build. I have a 9" out of mid sixties Ford Pickup that is 61" outside flange to outside flange. With BARE 5 & 1/2" wheels from a 50 Merc--inside wheel flange distance is 53 & 1/4" and outside to outside distance 66 & 1/4". For comparison, the truck now sits on Buick wire wheels with the stock banjo and wheel adapters. The best measurements I could get on this set up were as follows: inside (widest part of tire) is 53 & 1/2" and outside (widest part of tire) is 70 & 1/2". I realize my measurements aren't exactly apples to apples, but seems like the 61" axle will work ok too. Please let me know if you disagree and thank you in advance. Pete
Thank you, I found a guy who does 66-77' Broncos as a hobby 2 1/2 hrs from me. When I first contacted him about a rear axle he said he would sell a complete axle drum to drum 3.50 factory gear open differential for $300 but it wouldn't be taken out of a chassis till new yrs. I called him this last week to leave a deposit for one. He had to check his inventory and called back saying alls he had right now was a factory 3.50 posi drum to drum for $600 and I jumped on it!
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