1975 A833 od, any useful parts for non od boxes

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cpearce

cpearce

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Today I picked up an A body transmission of unknown origin. Didn't pay a whole bunch for it so I didn't investigate it to thoroughly. Once home I looked it over and saw it was a cast iron case with 1975 side cover 1976 case. I performed a tooth count and found out that unfortunately it is an od box. To bad because it is in excellent condition. I bought this hoping to use the main shaft to convert a 1965 trunion style trans over to standard output shaft.

Can you guys tell me if anything in this transmission will be worth keeping for either my 2.47 box, or the 3.09 box I have coming? Perhaps I should just sell the whole thing.
 
That's what a lot of guys are looking for when it comes to the od transmission, its the strongest. The aluminum cases ...they suck.
 
The input shaft/gear might be the same as your 3.09 trans. Check the tooth counts. Other than the synchro assemblies and the side cover and shift forks, the rest is different.
 
Hmmm not sure about the input shaft, thought it might be different too. You can swap the whole set of guts from an OD trans into a standard case or vice-versa (assuming you have a large bearing case), but you can't mix and match components.

Why is it too bad? An iron case 833 OD is almost as strong as a regular 833, plus an overdrive gear to boot. Gear spread is a little wide, but they're still great for a street car. If it doesn't work for your application you should be able to sell it complete for a decent chunk of money, the iron case OD's are more desirable.
 
Hey cpearce.

Are you in Alberta ? I have an A body main shaft and tail housing in BC if you are interested. Perhaps some kind of trade for the OD box? PM me for more info.

David
 
You can cut off the little tits, nubs or whatever you wanna call the of the (should be steel) shift forks & then use then in the early detent side cover. 1-2 syncro assembly should swap to up date old style 1-2 syncro assembly.
 
Thanks for the responses everyone. It seems I have no use for this box. The good news is that last night I scored a mint a body non od main shaft only 40 miles away. I likely will sell this one complete as a runner. The factory od transmission does not appeal to me with a strong 408.
 
A strong 408 is actually a decent application if it's not too crazy, the flat torque curve would help minimize the gear spread.

As far as strength, the 833 OD's don't get the credit they deserve. No, they are not as strong as a regular 833. But knowing people that have run aluminum case 833 OD's behind 440's at the drag strip for several seasons, in B/E bodies, I think most people really underestimate them. Same phenomenon with the 8.25 rear. Sure, you can break them and they aren't right for all applications, but they're capable of a lot more than people give them credit for. An iron case 833 OD eliminates one of the biggest issues that comes up with the OD transmissions, it really isn't that much weaker.

Sounds like you got it figured out though, and someone will buy that iron case 833 OD.
 
Mr Pierce, if that tranny is the one I steered you towards,I'm so sorry that deal went south.
Both synchronizer are bolt-ins for any other box,and the forks can be made to fit as well,either with the late cover, or cut off as mentioned for the early cover.But none of the gear-train will interchange with anything but exactly the same other box. And the mainshaft only fits the O/D box,no other.There are at least two O/D ratios that I know of and the only one gear that they share is the low-gear.
On another note;
A small-cam 408 streeter,would love that box, with 3.55s.
This will get you a 10.97 starter gear, and a 2.52 hiway gear.And everything Blu said above is right.That's a hard combo to fight. Heck, even I'd leave you alone.
So if you got it cheap enough, you might want to hang on to it for a bit. Perhaps the bug will bite, to check it out at some time in the future.
BTW, I think that extension of yours carries a rear bearing. The replacement M/S you just scored does not have provision for that. IDK if the tail is long enough for this shaft, but I guess you will find out. If you can't make it work, give me a shout, and I will send you one that will, as a token of apology.
 
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AJ/FormS said:
Mr Pierce, if that tranny is the one I steered you towards,I'm so sorry that deal went south.
Both synchronizer are bolt-ins for any other box,and the forks can be made to fit as well,either with the late cover, or cut off as mentioned for the early cover.But none of the gear-train will interchange with anything but exactly the same other box. And the mainshaft only fits the O/D box,no other.There are at least two O/D ratios that I know of and the only one gear that they share is the low-gear.
On another note;
A small-cam 408 streeter,would love that box, with 3.55s.
This will get you a 10.97 starter gear, and a 2.52 hiway gear.And everything Blu said above is right.That's a hard combo to fight. Heck, even I'd leave you alone.
So if you got it cheap enough, you might want to hang on to it for a bit. Perhaps the bug will bite, to check it out at some time in the future.
BTW, I think that extension of yours carries a rear bearing. The replacement M/S you just scored does not have provision for that. IDK if the tail is long enough for this shaft, but I guess you will find out. If you can't make it work, give me a shout, and I will send you one that will, as a token of apology.
Click to expand...
No,no its all good AJ. The one from bud is non od. The one I bought yesterday locally for a main shaft for Buds turned out to be od.
 
cpearce said:
No,no its all good AJ. The one from bud is non od. The one I bought yesterday locally for a main shaft for Buds turned out to be od.
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I think I will keep the cast iron od Trans also. I picked up an a body main shaft today to convert the one I bought from Bud to slip joint style tail.
 
Thank you everyone for all your responses, I always learn a lot from this site and you folks who are willing to share your knowledge and experiences.

I have decided to keep all three of my transmissions, the 2.47 box in all aluminum direct connection case, the cast iron case 3.09 OD, and the 1965 3.09 non od box I have coming. This certainly isn't my last Mopar and I'm not an automatic guy at all. Who knows what I will need down the road, these things are not exactly falling from the trees anymore.
 
AJ/FormS said:
There are at least two O/D ratios that I know of and the only one gear that they share is the low-gear.
Click to expand...

????

Never heard of that, unless one of the ratios is from Passon. Only ever heard of one set of OEM OD ratios in the A833.
 
The two ratios are .71od and .73 od
They both come with the 1 x 23 input and the only one gear they share between them is the m/s low. Even the clusters are different. The two o/d gears , IIRC are 18tooth and 20 tooth.I have examples of both. The 18 toother shatters with just the tiniest too much input, you have to be very gentle with it. My teener took it out just like that!
I suppose it would be fine with a slanty or even a 2bbl teener, but my teener had a big TQ and TTIs. And I gotta admit I made the mistake of banging into it with pretty good throttle. I forgot what tranny I was shifting that day. That teener was a test mule of sorts, and it experienced at least 3 or 4 different trannys in 4 or 5 separate winters, sometimes with the GV.
 
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The rest of the gears are the same ratio? Any documentation for this?

Not pretending to be an expert just never heard of anything like this.
 
Well since you are so persistant; hang tuff and I'll give you a tooth count.
OK here they come;
.....22-18-30-35
.....33-37-27-17
the calculated ratios are 3.088-1.67-1.00-.73od

.....24-20-30-35
.....36-42-27-17
..........and the ratios are 3.088-1.67-1.00-.71od

AFAIK, all mopar boxes have the same 35tooth first gear. Ima thinking that is as big a gear as they can fit into the box.
 
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I also ripped the teeth right off the 22tooth input gear,with my 360.IIRC I was going into 2-od with the GV, and a CFII disc. I believe this was with the 223/230/110 Hughes cam. That thing made some pretty good torque.
 
Hyup, got it documented in a binder I titled "Gearage"

As to which one you have, because the ratios are so very close together, I think the only way to know for sure is pop the cover and count the teeth. I tell you what tho, I sure hope you got lucky and have the 20Toother, cuz that little guy, won't take no crap I've seen more robust gears in much smaller 4-banger trannys..That guy should have an interlock connected to the carb, so you can only get into it on the primaries, cuz any secondary at all is enough to shred all the teeth off it.
Yeah so I retired those boxes many years ago.
 
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The od I just picked up is the .73 od.
 
MR P, good to hear from you again.
The .73 is the most common. In fact I have never seen another 20 toother, besides mine. I bought it as a spare, cuz I had already blown up two other od boxes. I was very surprised to find a completely different set of gears in there.
First and second gears in the .73 box , appear to be as robust as any other box. The input gear appears to be the same as the 3.09 direct box with 22teeth.
My 3.09/direct box also has the 22tooth input, and I have been unable to hurt it.
The regular mopar 2.66 box has a 24 tooth input, which being plus 2 teeth, we all know that box is tuff as nails.
The 2.47 box has the biggest input of all at 25 teeth;that box probably has the most robust gears of all.
 
AJ/FormS said:
The two o/d gears , IIRC are 18tooth and 20 tooth.I have examples of both. The 18 toother shatters with just the tiniest too much input, you have to be very gentle with it.
Click to expand...

Is this maybe backwards? Based on the below, the .73 OD uses the 18 tooth gear, but it almost seems like you prefer the .73 OD. Am I misunderstanding?

AJ/FormS said:
.....22-18-30-35
.....33-37-27-17
the calculated ratios are 3.088-1.67-1.00-.73od

.....24-20-30-35
.....36-42-27-17
..........and the ratios are 3.088-1.67-1.00-.71od
Click to expand...

How about the output size? Any relation between the gears and size of the output? Pretty sure mine is a 727 size output, and seems like it came out of a '76 Feather Duster. I know it is an all aluminum case, too.

Lastly, here is a link to some old info I posted some time ago about swapping OD parts into a non-OD case. Just some more info. Old Hot Rod Article about converting a std 4 speed to OD
 
Oh no,The 20tooth o/d gear is much stronger, and I prefer it. But it seems to be somewhat rare.
The output shafts between the od and the std are completely different and there is no possible way to make one fit the other. Well you could adapt the od m/s into the std box by manufacturing a bushing at the 3rd gear position and using the od hub; but I don't think that hub would last very long. It was never designed to accept any kind of torque.
And yes, I have seen two flavors of od mainshafts; the 904 size, and the 727 size and even a GM size. There was also a 10spl input for chebby trucks, in a case with a chebby front end,IIRC. I think the application was for a chebby pick-up of late 70s early 80s, and a big 6banger;250 I think.I had opportunity to buy a half dozen of those a few years ago but the only useful parts for me were the syncronizer assemblies and the o/d gears themselves. And I felt the firm asking price was too high. Turns out it was a good decision, as I very quickly got away from od boxes.
Don't worry about the 18 toother; just be nice to it,going in.
 
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