I did a search but came up empty handed for an answer on this question. I'd like to use my 33 ford torquetube and driveshaft on my 40 ford rearend. It's going into a 34 ford coupe with a 59AB flathead and a 40 ford transmission. Is the 40 rearend that much stronger than the stock 33 rearend or should I just bolt the 40 brakes onto my complete 33 rear axle assembly? Also, I've heard one has a 6 spline sleeve and the other has a 10 spline sleeve. If I decide to use the 33 driveshaft/torquetube on the 40 axle, will I be able to use a Speedway 6/10 spline adapter and not have to cut my 33 tube and shaft? After all, it's going into a 33/34 ford. Unless my 40 transmission is a different length than the original 33/34 transmission [I don't have one to measure] this should all bolt up without needing to shorten any tourqetube or driveshaft. Right?
1. Although there are many dimensional differences between a '34 and a '40 rear, the overall design strength is the same. 2. The '40 banjo is longer than the '34 banjo, so the torque tube will be 7/16" forward. 3. The inner diameter of the '34 t-tube is smaller than the '40. It will drag on the cage of the '40 pinion bearing unless you machine it. 4. The '34 drive shaft is tubular. You would have to cut out the 10 spline coupler, machine the 10/6 adapter to fit in the tube, and weld it in place. If the '34 is in good shape (ring and pinion etc) I'd use it with '40 brakes.
Yeah, I just measured both of 'em this evening but with the "bent-in-the-middle" 33-34 spring, I believe it puts the rear wheel centered in the wheelwell. The 40 was about 4.5" from spring to housing and the 33 was about 2.5". But, the center of the 33-34 spring is about 2 inches further back than a straight 40 spring. The rub is gonna be the "bend" in the 33-34 crossmember to receive a straight 40 spring...would take a little welding to repair.
Check the gear ratio. Not very highway friendly on most 33-34s.... You can use a 35-48 r&p , but you have to machine it. That is what i did on my '33 Michael
Not for sure but at least now I see several options I can use, including Micky's advice. I still don't know about this 6 to 10 spline adapter. Will it add length to my 33 driveshaft? Is it a bolt-in deal? I'd rather use my 40 [I also have a good, complete 41 rear axle that appears to be identical to my 40 axle except it has stabilizer bar mount ears...a great place to mount tube shocks or even a stabilizer bar] axle because it's got 3.78 gears....I'd imagine the 33 has 4.11s but I can't see the stamped-in number on the 33's housing.
when i just did my 32 tudor i used a 40 rear, i shortened the 40 torque tube, the 40 drive shaft, the 40 bones, and i also used the 40 spring with the stock spring mounts etc etc, i just ground the 40 spring to fit into the 32 crossmember, a buddy told me that the center line of the axle to the center line of the spring is supsose to be the same, i put it in my 32 that way and the wheels seem pretty damn close to the center of the wheel well, now i dont have fenders so it could be off a little bit but very little. JEFF
Good to hear of progrees Rock........things on my projects, the state switched computer systems and they STILL dont have the bugs worked out. Waiting for a less stressfull day than now
No. It's not a bolt in deal. The '34 driveshaft is a tube, not a shaft. The rear of the '34 drive shaft tube has a 10 spline coupler welded into the end of it. It must be removed, then a new 6 spline coupler must be machined to fit and welded in. We machine the 10/6 adapter to fit the end of the '34 driveshaft tube with the 6 spline end extended to fit the 6 spline pinion gear. We use a 6/10 coupler because the 6 spline couplers are too small to fit into the '34 driveshaft tube.
yes. You must machine the pinion shaft to accept the '34 pinion bearings, and the tooth OD must be turned down to fit into the '34 banjo housing. The drive shaft must be shortened, which you do when you put in the new 6 spline coupler.
How much wider is a '40 axle than a '33-'34 one? I'm trying to decide what axle to use to put hydraulics on my '34 Tudor - the simplest way would be to fit the late brakes to the original axle, but as it is at present with the stock axle the rear wheels ('40 steels) are tucked under too far. If I just change the brakes and then fit 7.00-16s on 4 1/2" Ford wheels they are going to be pretty tight to the chassis/wheel well.
All the more reason for me to use a 40/41 rear. A quick and dirty measurement tells me the 40/41 rear is about 1.5" wider at the backing plates. This assumes the distance from the backing plate to the wheel mounting surface is the same 33 to 40 and I believe it's a safe assumption. Thanks for the info on the coupler/spline differences. Seems it would be best for me to use my entire 40/41 rear and shorten both the tube and the shaft.
If you are going to the 40 and have to shorten it, check into putting in the 9" axle adaptor kit that HOT ROD SHOP has. If you are cutting and welding, why not upgrade while you are there? And get away from the keyed shafts.
Andy - I bolted '46-48 brakes onto my '34 in the UK & ran 16 x 4.5" wheels & 7.50 x 16" tyres. I had no clearance issues. The hydraulic brakes are canted forward a bit when bolted to the '33/34 banjo, but nothing too dramatic - I've got pics somewhere I can dig up if you need them.
Good advice here!!! especially if your bearing surfaces are shot(which they are most of the times anyway) then you have to machine the housings anyway. Like the last two years before i forgot to call HRW before LARS and bring a conversion for my 40 rear.............too late. Michael
Hi Ernie, thanks. It just seems that when looking at the rear the tyres are well tucked in, and I figured that as the extra 1/2" on the Ford wheels all seems to go on the back side it would move the tyre centre in another 1/4" (if I ever find another 5" rim to make a pair, it'll be 1/2" further in!).
I don't recall mine being tucked in too far - not sure I have any close-up pics of the centre of the wheel/tyre in the fenderwell. I do know I did not have any rubbing issues anywhere... The 7.50x16 tyres are actually slightly narrower than the 7.00x16 tyres, so perhaps that was the difference?? Only pic I could find...
Mine's got these big old Delco lever arm shocks that hang outside of the chassis, making it worse. I'm hoping to fit some tube shocks as well while I'm messing about under there.
I had to remove the Delcos that were on mine - you can actually see where they rubbed on the inside of the tyre in that pic. I think I ended up putting stock lever shockers on...
So if I put a straight spring on and run 36/ wishbones u think that will center my axle on a 34 frame I'm building
What is it with all the old threads? What axle are you going to use? A 40 front spring will go into the bent crossmembers and is shorter than the bent springs. A 40 rear spring will require surgery to the crossmember and may not clear your backing plates.
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