I know this is a amateur question but what needs to be done to put a 1940 rear in a 29 model A using a model a spring and v8 halibrand centersection I have never done this before and know alot of you guys have. any or all help would be great thanks
I put a 41 Merc rear in my coupe. It needed to be cut down almost 24 inches. I had Bear Metal Kustoms do it.
You can put the A spring on the '40 rear with the stock bones, but it will move the wheels up about three inches. I haven't tried to search but that might be the option, or pick up the book everyone recommends, "How To Build Early Ford Hot Rods" -
Tardel/Bishop Book "How To Build A Traditional Ford Hot Rod" explains it in further detail. Use the 40 Banjo Rearend & Wishbones. Use the Model A Rear Spring. Buy a pair of ductile steel spring hangers and weld them to the top of the axle housings. Done.
Spring on top of the axle, like a model A - no chassis lengthening. However, you can't get as low without stepping the frame, reversing the spring eyes and you have to weld spring hangers on as described by TexasHardCore - get them from Pete & Jakes through Riley Auto Spring behind the axle, like a later car - the spring is now 7" or so further back and mounted much lower, so you have to extend the mount by lengthening the chassis or bumping the rear crossmember back, but you don't have to reverse the spring eyes (but you can to go lower). Depending upon the bones you use, you may still have to weld on spring mounts, but not the same style, because some of the later bones have integrated spring mounts. This style of weld-on mounth are also available from P&J. Good luck, keep searching. I did the weld on, top mount spring on my A. Pretty simple to to do. The hardest part was finding a spring shop to shorten and reverse the eyes on my spring. Its still not 100% right, but that is on the list of things to fix later.
model A rear bones are kind of weak. i think you are better off with the 40 wishbone. just mount the A rear spring over that 40 banjo
I'm running this setup on my A roadster, (pics on Hardtop57's post #4070688), with a '39 style trans. I set my spring on top using a Posie's narrowed, 46", spring and homemade hangers kinda' like the Speedway ones. My car sets kind of high intentionally. I carefully cut the radius rod mount off the torque tube with a cutting wheel in a die grinder, relocated it to reuse the '40 bones, and shortened the torque tube and driveshaft myself about 22 5/8". There is some play in that number depending on where you set your trans at. If you like, PM me and I'll talk you through how to shorten an early Ford driveline without a machine shop, ( I know a dozen people are going to tell me you can't), but you can if you go about it right. My Dad taught me how to do it in the fifties at his Texaco station on a wooden work bench. They used to run this combination under a very potent Olds powered 29 chevy roadster. Mine works great. This is a really good combination.
I talked to some rodders and read some jobs done in a mag. Measured and cut the drive shaft and mounted the a spring on top of the axle housing just like the stock A mounting. In fact used the A hanger, welded it on. Heated the spring to drop the ends. ggggg [close but don,t do it this way today Dave M ,1956]
In reference to the reply above. It is really very easy to shorten a Ford torque tube. Using any early Ford tube that is not tapered, (like a '34), you want a tube that has, at least for the part your cutting out, a consistent diameter. My favorites are the '41 to '48 but just about any will do. Determine the lenght of the torque tube you will need. This will vary from car to car, and even among cars using the same setup depending on where the engine is mounted etc.. You just need to accurately determine the lenght you need, no rocket science here. Using a plumbers pipe cutter, the kind with the wheel in which every plumber, pipe fitter, sprinkler guy and a hundred other trades use, cut as close to the rear flange, (where it bolts onto the banjo), as possible. You can usually get about a 1/2" away and take the flange off. Now remove whatever length required to make your torque tube the right lenght from the tube you removed. The pipe cutter, for this application, is as accurate as a lathe cut. Now I gently chamfer the cut ends about halfway through to assure a good weld penetration. Remember early Ford rears were not only a driveline component but the rear suspension as well. Record the lenght you removed from the tube as you will need to remove the same amount from the driveshaft. Clamp the two pieces together, (I just use a piece of All Thread through the center thats been laying around forever with some plates on the ends), making sure the two pieces are properly aligned. Weld carefully and competently. Next take the driveshaft and remove the coupler. Using whatever dimension you removed from the torque tube, remove the same amount from the driveshaft. I just use an abrasive cut off saw for this work but just about anything except a torch is OK. I prefer to use the solid steel driveshaft but you can use whatever you have. On a solid shaft layout the splines on the cut end of the shaft and as accuratly as you can and cut the splines into the shaft using a small cut off wheel in a die grinder or angle grinder. As the coupler is a slip fit on the shaft the accuracy of these splines is not critical, just get them decent. Tap the coupler, to the same depth as it origionally was, onto the splines you just created and weld it to the shaft. If you have a tube driveshaft I just remove the appropriate lenght from the tube as close to the rear as possible, chamfer the cut ends for weld penetration, and insert about a 6", .120 wall DOM tubing sleeve into the joint to align, and weld. Reassemble the thing. Carefully remove the front clip that holds your radius rods with a cut off wheel and assemble your radius rods and the clip to the rear hangers. Clamp the clip to the shortened torque tube and weld away. As always when welding any drive line component be aware of weld pull caused by cooking the parts. Another words, skip around while welding so as not to warp the tubes. This is important when welding anything that alignment matters and has been covered many times in other threads. This is caveman tech at its best. I will say that I can't imagine how many of these my Dad did in his shop between '40 and '69, nor how many I've did since but I've never had even one that broke, (at least from the shorten job, I can pretty much break anything), or had balance/misalignment problems. Be careful and use common sense and this works every time. I'd be interested in other techniques and comments on this method. If anybody's interested I have another one to cut next week for under Sr's modified, ( Aces & Eights), and maybe I can have Hardtop 57 photograph while I do it and post the details. I'm a really good fabricator but suck at computers and the like. Good luck, and let me know if you need any additional info.
Can you use the '40 bones on any open rear besides the late 40's pickup banjo? Like say a 9" Ford? Or is that a dumb question.
Remember all early Ford bones were really lateral stabilizers and the torque tube was the structural component in the banjo setup. I've never felt comfortable using early Ford rear bones as suspension components in an open driveline setup. I know it's been done many times but that doesn't mean it's a good setup. Rolling Bones uses these as lower components in a traditional triangular ladder bar arrangement using them as only a part of the suspension, (the part you see), and using what I assume to be 7/8 x .156 wall DOM as the other. One of the rod magazines recently did a tech on this but I can't remember which one, probably Street Rodder.
As a side note, most early Ford bones are relativly easy to switch from rear to rear. I find the '41 to '48 ones to be the most useful. They seem to be the beefyest and are a good lenght under A's and other cars of similar wheelbase.
Koz thanks for the tech ya it would be great if you could get Hardtop 57 to take some photographs while you do the next one and post the details
May I suggest you step it up something like this, as it has so much more strength than welding the bottom rail onto the top rail. A length of tubing was welded onto the mail chassis rail, after both were tapered. When finished both methods look very sililar from under the car, but this one is a hell of a lot stronger
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