Hello all. I am trying to work out what my options are to achieve the following using traditional HAMB parts or make something that would have worked from the era. For the sake of this discussion if I have a 261 Chev and want overdrive gearing, how can I achieve it. I am happy for both auto and manual suggestions. I prefer manual but auto looks more attractive as I age and traffic constantly gets worse. The 261 will be going into a 1941 Chev pickup with later diff(not torque tube). I know I can get a T5 or T700, or an expensive new OD unit but I am not keen. I am in Australia and a Holden 3 or 4 speed would bolt up but they are not overdrive. I like the idea of a 3 speed column shift with a traditional style mod behind that wont cost the earth. Or is it possible to convert a diff to 2 speed and run a high diff ratio. With the tires I am using I could get away with around 2.8:1 diff for the high speed. How can I do this? Steve
261s were installed in larger trucks, and were designed to be running at high rpm, and moving slowly....why don't you just put in 3.90 gears from a 55-62 Chevy pickup (this center section fits the 41 truck housing and axles), and whatever 3 or 4 speed non-OD transmission you can find, and drive it? How fast do you want to go, anyways? 80 mph?
The obvious answer is I don't want to. For more detail I find low revving relaxing and high revving engines on the highway stressful. It is not about top speed but highway revs. Also the 261 will be rebuilt with a focus on low end torque, because that is what I like. I know you are a fountain of knowledge and normally give good technical responses but in this case it is as I commented in another post. Educate me on how it can be possibly achieved, if i didn't want to know I would not have asked. It was not like I asked how I can put a modern transmission behind a 261. Steve
Can you find one of the Borg Warner overdrive equipped 3 speed transmissions used on Chevys from the mid 50s to late 60s? They will give you what you want. I don't have any idea how hard they are to find over there.
This is the early style, non-synchro low gear, Muncie SM319 This is the later style, Saginaw, full synchro
I shopped around a bit for one of the trans pictured above, for my '56 Vette, but they won't work with the floor shifter, plus the tunnel is too small. Anyway I saw a couple around $500 here in the USA. How about a second 3 speed backwards? Crazy, but cheap!
Either the Borg-Warner @squirrel posted or a Ruckstell where used back in the day . both trans posted are good options, I used a T5 out of a v6 s10 when I built my 261 with a 373 rear . if you get a bell housing from a 55 and newer Chevy car or truck a modern trans will bolt in, some trimming of the input shaft maybe required or a adapter plate ( shim) is necessary.
@Reidy, I have exactly what you need. Saginaw 4 speed with O.D. adapted from Saginaw 3 speed. The only problem is that it weighs about 100 lbs. and is here in Michigan. If you know how I could ship it to you reasonably, send me a personal message and we can work something out.
If you can find one of the Saginaws like in @squirrel post, the OD unit can be merged with a Saginaw 4 speed to create a 4 speed with OD. Probably not easy to find. .bjb
Thanks Squirrel and others for the suggestions. I did not know such a box existed. I don't know how hard it will be to find but at least I know what I am looking for. We imported a lot of US cars and trucks, what were they mainly fitted to? Steve
Use the 6 cylinder/ 253 Aussie M20 wide ratio 4 speed [which is not a muncie] , then use a 2.77 :1 Borg Warner 78 rear end [XE-XF Fairmont Ghia] aka the 9 Bolt in the USA You need the low ratio 1st of the wide ratio M20 to get it off the line, and the 2.77 will give good cruising manners The 6 cyl / 253 M20 has a 3.07 first gear , x 2.77:1 rear would yield a total of 8.50 : 1 [in first] This compares to a Muncie M20 2.54 first with a 3.35 Rear end , or a Muncie M21 2.20 first with a 3.86:1 Rear end But you will have the tall 4th Gear. [which is the same as a 3+1] Another alternative is the Aussie / Kiwi Toyota 5 speed Transmission to Chevy/Holden conversion The internals from a Hi-Lux, Cressida, Hi-ace are all interchangeable in these transmissions. Now thinking outside the box here, the Toyota HiAce van has a different casing with cable shift, And the early Hi-ace and Some Lite-Ace trucks had a 5 speed column shift. I have a friend with an off-road truck that has a huge engine setback, He used a Supra close ratio internals inside a Hi-ace casing. This allowed him to use the cable shift and a van floor shift [in normal shifter position] Dellow do conversions in Australia.
The manual 3 spd with a Borg Warner o/d were and option from '55-'56 to '73ish (?) cars and trucks, V8 and 6cyl. The Saginaw trans has a synchronized 1st gear and are harder to find. Here's a link to the old manual for one. https://www.oldwillysforum.com/forum/TechData/BWOverdriveManual.pdf
also known as the MY6. Just about unknown downunder. It would be cheaper to install a TKO 500 than import the Chrysler/GM 3+1 trans. Plus they have a unique bellhousing , and the 261 needs the factory bellhousing with engine mounts pads.
A 48/53 Chevy truck bellhousing should be a bolt in in the 41 behind the 261 and has the transmission bolt pattern that matches the "Muncie pattern" that is on the transmissions that Squirrel posted in post 6. I'll have to go out in the shed tomorrow and take a couple of photos of one from a 51 that I have for show and tell. What I am thinking is that there should be a common in OZ overdrive transmission that you have readily available adapters to bolt it to the later style (48 and up truck 55 and up car) bellhousing bolt pattern. They won't be inexpensive but if you could use something like a W56 out of a Toyota pickup the cost of the adapter may be far less than trying to get something from the states.
@Reidy , a 253 M20 will work well. With a 2.8 to 1 rear end you will get the following rpm/speeds. 1st gear (3.05:1) at 3500 rpm you will be doing 53 kph (33 mph). 2nd gear (2.19:1) at 3500 rpm you will be doing 74 kph (46 mph). 3rd gear (1.51:1) at 3500 rpm you will be doing 108 kph (67 mph). 4th gear as overdrive (1:1) at 2150 rpm you will be cruising at 100 kph (62 mph).
Forgot about that. I’m plan on using a t-5 behind mine unless a run across a 3spd od gm offering. Using the 48 up bell opens up more opportunities
How about the Ford toploader 3+1 OD four speed commonly used in many '80s Ford pickup trucks and vans? They are rugged and relatively plentiful, thus cheaper and meant for trucks. I had a couple with floor shifters in my vans of that era. BTW, if the thought of having to modify your tunnel is not an option for you that is going to severely limit your chances of a solution. Tunnel and crossmember mods would not deter me on a project like this.
GM built an overdrive five speed back during WWII. Great transmission but wasn’t sycroed. You can find them in the early GI trucks. Might be a bolt in and have a floor shift! Bones
That 253 trans seems like a good solution that you should be able to find in AU. The wide ratiio helps with a taller rearend gear. Also given that you said your engine build was going to be for more lower end torque, that helps with the wide ratio trans.
Are those option O/D's that came with Fridge F100's worth considering? I think they were and electric switch arrangement!
They came in a lot of Studes(don't know how available they are down there. A friends' friend imports a lot from CA - or did - but mostly hi-po Stude stuff), ~46->64 (Champion6, Commander6, v8) when equipped w/manual trans. Borg Warner T86(R-10), T85(R-11). Both 3 sp. Longer input shaft, iirc, but that makes it easy to adapt. T86 wasn't super strong, but iffen you aren't using it hard, should work. Another way is using the Volvo OD box, from 50s->60s, maybe 70s. I don't recall the box #s. Tough box. Or, turn around a 3sp running it backwards after the 1st trans, & use it like a Brownie Box, but the jump in ratios might be a bit hard to deal with. GearheadsQCE would be a good deal, iffen it doesn't cost the earth to ship. Marcus...
Chrysler royals came out with a 3 Spd OD box here in Oz. Column change just like you’re talking. Make an adapter plate and away you go.
I’ve been curious about this. Could a tail shaft from a non OD trans that was common to have an R10 unit be used to create this?
I did what you are talking about in my 59 Ford, but not with HAMB era parts. Used a '79 Pony car 3+OD. Known as a top loader imposter.
Hey, Anthony; Have seen similar, but they used a flat plate w/a seal at the front of the OD, & then used an internal splined coupler on the (I think) resplined input shaft. But not the tailshaft box being used that way, does look like the way to go. I don't know if the bolt pattern(s) are symmetrical to easily swap around. Still, a nice useful idea. Also, in the 50's->mid 60's, Rancho made an R-10 OD w/an adapter(flat plate) to bolt onto the rear output of the Dana18 transfer case. Only useable in 2wl dr. Hard to find now. IIRC, Barney Navarro(?) made an adapter for an R-10 to be placed in the driveline, somewhat like the pic you showed. Never read anything more of it. Guessing that went thru a few folks, eventually morphing into GearVendors OD. Which shares nothing w/any BW R-10/11. Marcus...
Hone made a planetary overdrive, manually shifted, that could either bolt to the front of a 9" ford rear end housing in place of the pinion support, or it could be purchased with a Ujoint yoke at each end. Long out of production. The GV overdrive is the British Laycock de Normanville unit, totally unrelated to the BW stuff.
The thing is, you don't want to search forever for some esoteric transmission that is difficult if not impossible to get parts for..........and then have a problem later on. 5 speed transmissions have become an acceptable alternative on the Hamb and virtually everywhere else in hot rodding. Some people even install them in "restored " vehicles just so they can enjoy driving them. Most are strong enough for your 6's power and they will give you a much better low gear than a 3 speed/OD as well as a really nice crusing rpm in OD. They should be reasonably easy to find, reasonably cheap to buy, and repair parts available for years to come. Usually never hear anyone who has gone from a conventional 3 speed to a 5 speed wishing that they hadn't. You might even find a 6 speed from a "foreign" car that could be adapted. Gears is your friend...........
Reidy, this article may help: https://www.motortrend.com/how-to/gear-vendors-vs-warn-vs-ranger-overdrives/ The Ranger went ahead of the trans. Moves the can of worms to the other end (bell housing, input shaft, clutch). Could be interesting, if you could find one. Good hunting, Mike
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