This has Probably been asked before, but Are Model A rears strong enough for a Flathead AV8 conversion? I don't want a 9 sec Flathead but an angry street car would be cool. Im going for a early 50's style lakes car and I would like the look of the A diff. Is there any threads on this? opinions?
Will last a long time if you baby it. Let the car develop some momentum before you open the throttle. Rev it up and drop the clutch at every stop light and it won't last long. A V8 diff will be a better.
I'm interested, too! What is the weak link in the A banjo? What is included/improved with the hot rod works conversion? Nevermind on the axle conversion...for $1300, I'd do a later banjo or even a used swapmeet quickchange.
The 37-41 and later have a bearing and support for the end of the pinion where it meets the ring gear. You could run that center section with the A axles/spiders and bells i think. Use the rest of the 37-41 guts.
Even with the V8 rear end we used to regularly spit out the axle keyways with a healthy flat motor. Wouldn't even consider a banger rear end. A V8 Banjo with the Hot Rod Works axles seems to hold up pretty well to hooliganism.
There's a thread somewhere here on installing a bronze snubber bolt into the housing to stop the crown wheel climbing up the pinion under power. That, plus a rolling start will make it last long time. A rears used to be commonplace in AV8s back in the 50s. There's also info on installing hydraulic brakes. Search threads by Gashog, he did an excellent thread with pics.
The Model A rear axle can handle a stock 40 hp 4-banger and skinny 4.75 X19 tires just fine. That's about it. Mart3406 ============
The support for the end of the pinion started in late 1932 and was the standard from 1933 through 1948. Charlie Stephens
Axle keys are the weak link. A stock, wore-out four banger will strip axle keys all day long if you abuse it. My sense is that they were desinged as a "fuse", that could be easily replaced and prevent more serious damage. I solved my abuse problem by swapping in a heavier AA truck axle, but 7.25:1 gears are no solution for your average hot rod.
You also need to be careful with the wishbone if you split it. (Even if you don't split them, I'd guess) They're pretty flimsy and I've seen them fold up under flathead power. Someone suggested using A bells, axles, and spiders with a V8 center. Not sure I see the benefit with that. Why not just use a V8 assembly and add the A spring perches...??.. HRW's work and service are superb.... Well worth the investment if you have the money to spend.
If you have an A axle already it's cheaper, (and less work the welding on perches if you have bells with them already on them) to swap the parts if you're doing a rebuild. I figured that was kind of obvious but, well.....
Been running 31 banjo for 20 years behind a flattie. Been through 8 transmissions so far but no rearends. Butch
Awesome thanks guys. If I could run something else watch should I look for in banjos? Anything between 39 & 45 is very difficult to get here Because during the war we got bugger all passenger cars. It wold be cool to run an A' rear but I don't wanna break it everytime I want to scare the shit out of someone. ;p
Yep, nothing worse than trying to be Cool or Scare someone, do your little burnout and then have it break only to limp away with your tail between your legs
Well I ran a 296 Flattie with a 25 tooth box and A rear and never had a issue with the rear,trans YES!! T RPU with 7+inch wide 8.20 X15 stock car specials.Replace the U joint every time I blew up a trans 'cause the yoke ears were spread apart a 1/4' Did have the axles laped to the hub and 200+ flbs of torque on the axle nuts.
I agree with you about cost, etc, but how do you adapt the early A bells to the later V8 center given the difference in diameters?? A axle bells are 9 3/4" V8 axle bells are 10"
Model a rear ends will hold up just fine behind a healthy flathead. Top fuel drag racers used ford flathead rear ends all the time and won many races. They where closed drive shaft torque tube rear to keep everything strait and in line. If hemi , olds and buick engines didn't break em the flathead wont.
Thanks guys very helpful. I think I'll just run it and if breaks it breaks. Of course a quick change is on the list, so maybe if I. Break it she'll let me re mortgage the house haha Posted using the Full Custom H.A.M.B. App!
Get a hub puller, and some extra axle keys. Carry them. Neither are a common part, in any hemisphere.
I have a model A rear in my '30 pick up, drove it for 10 years daily with a merc flatty. It broke 1 axle in that time, & that was cruising on the freeway. I'm just putting a fresh flatty as we speak & the A rear is staying put, maybe I have been lucky. Good Luck.
Hopefully a bit that luck stays with me. Especially at 60 mile an hour haha Posted using the Full Custom H.A.M.B. App!
Now you have put in the extra piece of info about wanting a QC, I will add my thoughts. Standard Model A rears are still pretty easy to find here, and can be treated as a disposal item when you blow one up.......... but blowing apart a QC equiped Model A will bring tears to the minister for war and finances eyes, and yours shortly there after The only readily available QC's I know of for a Model A rear are original Halibrand 101 series QC and the KiwiQuickchanre repro of the 101H. The repop is A$2200 landed at your door in Oz (last I checked) and I have seen an original 101 fetch anywhere up to $6k I would only do either if I was building a parts correct late 40's Model A ........... which I am, and am lucky enough to have a bloody nice, first pattern 101, circa 1946. Behind a mildly breathed on Banger, but with a more radical B with OHV head waiting in the wings. I consider the 101 marginal behind a serious Banger, but have it and want to run it. BUT ........ given the dollars involved, and relative strength ....... if I was starting from a clean slate, and wasn't after a parts correct late 40's car then I would go with a Halibrand 201 or repop. KiwiQuickchange do them for the same price, and Rodsville and a few others also do them. The 201 is significantly stronger, and take 35 - 48 gizzards and housings which are also stronger Give me a bell on 0421 052 341 if you want to chat about these diffs, I have done a few early Ford diffs, but this is my first QC
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