I want to put a 48 ford rear end center section in my 34 ford rear end. By putting the 34 ford axels and axel housings on the 48 ford center section it will give me the proper rear end length with the advantages of the newer ford center section. Has anyone done this conversion?
that doesnt work. the bolt pattern to attach the axle bells is clocked different 35&up. also, the 35 & up center section has the face where the torque tube mounts 9/16" farther to the front to accommodate the larger pinion bearings. best bet is to get a 37-41 rear end, use the spring for that rear and grind it to fit the 34 curved cross member. then shorten the drive shaft and tube by 9/16". yup, and the center is wider too, forgot that part!
here's the scope on center sections. on the left is a 32-34, narrower, smaller pinion bearings, and no web cast in for support of the pinion. the center is 35 to? not sure when the change occurred, but bigger pinion bearings, wider case, 5/16"if i remember, 9/16 longer snout on the front flange/tt mount, and some small webs cast in to help support the pinion bearings. on the right, the later case, not sure when it started, but notice ford now put a much longer web to support the pinion. so the point being, if you are a guy that likes to side step the clutch and burn rubber, the later diff is only slightly better. if you have big horsepower and you like to use it to impress your friends, you may opt for a different rear altogether. i am a low hp banjo guy myself, tires cost money !
I was hoping someone on The Hamb had done this before and would comment. It looks to me that the clocking problem can be solved one of three ways: 1) go to an open driveline, 2) cut and re-weld the axel housings at the spring perches and 3) possibly heat and bend the spring perches. As far as the driveline being 9/16 too long, that should be fixable also. The problem I see as most concerning is the carrier bearings. The 34 bearings are smaller than the 48 bearings. Are they interchangeable? Which one should I use? Is this going to be a big problem? Am I barking up the wrong tree?
I have seen it mentioned here on the HAMB that the conversion of '32 - '34 axles and axle housings to mount the later '35 - '48 center sections can be done with "special" modifications. However, I have never seen a description of how it is accomplished given the differences in various dimensions. Perhaps someone knows the details. The other choice to consider is to modify the later ring and pinion to fit into the early banjo, if the goal is merely to get a different ratio.
What is the ultimate goal? I have a late 32 rear with 48 ring and pinion inside it. So I know that can be done.
I have a '34 rear axle in my 3W coupe and a built stroker Flathead that I launch hard when drag racing, to me it seems like a lot of work/machining to the have a slightly stronger later Banjo center section, the truth is '32-'34 Banjos differentials are plenty strong for a built Flathead and stronger than you think, the '39 gear box actually the weaker link, you can destroy a cluster before you break a rear end, remember tight drums and tire spin are your friends.
i have a 34 rear with 36 ring and pinion. to do that, you have a crankshaft grinder grind the later pinion bearing surface down to the bearing size of the 32-34. this is usually done to change the ratio, or the spline count, and or to use a gear set you have in stock and want to save some money. you do not gain any strength because you are still using the small pinion bearings. the late great rumbleseat claimed to put the wide/late center in his 34 by machining the ends of his 34 axles shorter to accommodate the wider center. he did not discuss the clock on the bells. its all possible if you are the machinist and want a fun project, but if you have to hire this all out you will have an expensive rear that is still not bullet proof.
You asked me what the ultimate goal is. I have two rear ends. One is a 34 and the other is a 48. Neither is in the best of shape or complete. Banjo rear ends complete or not, in any shape, are hard to find and are too heavy and large to ship so I am hoping to make one good rear end from the two of them that will accept an aftermarket gear set. I plan to install it in the flathead powered 33 Ford Tudor sedan I am building.
I am surprised at the lack of banjo rearends around your area. I've got a pile of about a dozen behind my garage, and could probably find another dozen in a day if I needed them. Don't make more work than is needed just because you haven't found the right base for the project. Spend a little time asking around. I'm sure there is somebody near you that has one, or knows of one for sale. Sounds like the best thing for you would be a 33-34 rear, and you can modify some late gears to get the ratio you want. Or, I think there may even be 33-34 gears available new in desirable ratios.
since you have a good set of 34 tubes and axles, why not install a QC? Talk with the guys at Hot Rod Works. they can help you out. personally I use the 35-36 rears in the 32-34 cars, just slightly wider. the 37 and up are to wide and mess up the aesthetics.
I came to the conclusion that due to the larger bearings the 48 center section will not work with the 34 axel housings so I am presently looking for a 35-36 rear end which use the smaller bearings.
I have a stock model A rear under the roadster I built..It has a stroker flathead in front of it and has been raced at many events with no breakage.. Also built this 33 coupe with a blown, stroker flathead with a stock 34 rear and again, no breakage..I raced the shit out of it.. IMHO,run the stock 34 rear..forget trying to reinvent the wheel here..If you break the rear diff, replace it..If you're afraid of breaking stuff,put a 9" ford behind it and forget about it...
The bearings I am referring to are the carrier bearings. The carrier in my 34 rear end has problems and needs to be replaced. I am located in southern Oregon.
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