A833 overdrive V8 bellhousing?

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Evan Dutch

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Hello,

I’ve got a slant six with an a833 overdrive 4 speed. I would like to swap the slant 6 for a 360 I have and I would like to keep the 4 speed. I know that I would need a v8 bellhousing since the starter is in a different location. Is there any difference between a regular a833 bellhousing and an overdrive a833 bellhousing? Also where could I find such a bellhousing and what else would I need to complete the swap?

Thanks.
 
The o/d trans has a larger front bearing retainer than a non-o/d trans. The o/d bellhousing has a corresponding larger hole.
 
The 833OD bellhousing has a 5.125" register because the input bearing retainer on an 833OD transmission has a 5.125" diameter. The regular 833's are either 4.3" or 4.8", all the A-body 833's had a 4.3" retainer.

The bellhousing you're looking for has casting #3743859, it came on 75-76 A bodies, 1975-80 F bodies, and 76-80 light trucks. This what you need, you'll just have to find one
Brewer's Performance - Mopar A833 4-Speed Transmission and Component Specialists

As for other differences, all the linkage is different. Z-bar, clutch linkage, etc will all have to be changed.
 
I have an A833 Overdrive on my 318, I ran into the same issue. ME and my friend swapped the guts from the transmission with the aluminum housing into an iron case. To do this you need to grind off a small part of the part in which the reverse shaft gear goes. After that it was smooth sailing used my same bell housing and have the added strength (and weight :D) of the iron case!
 
Hello,

I’ve got a slant six with an a833 overdrive 4 speed. I would like to swap the slant 6 for a 360 I have and I would like to keep the 4 speed. I know that I would need a v8 bellhousing since the starter is in a different location. Is there any difference between a regular a833 bellhousing and an overdrive a833 bellhousing? Also where could I find such a bellhousing and what else would I need to complete the swap?

Thanks.
 
Im new here and to mopars. Did you find a bellhousing and did it all work out? I swear i viewed this post before and there were two replies of members claiming they had this bellhousing with the 5.125 index, but now I do not see those replies.
I have a 76 duster with a 225 I just picked up and a small block waiting for me to acquire all the parts!
 
I have a 76 duster with a 225 I just picked up and a small block waiting for me to acquire all the parts!

/6 A833s also have the smaller mainshaft that fits 904 yokes versus the V8 shafts that take the 727 yoke. Bearings are also different; 307-type on the small and 308TYPE on the v8s.
In most cases the cast-iron case will have to be clearanced for the big overdrive cluster gear.
BTW
I used the alloy overdrive case for several years behind my Hi-torque 367. Butum I installed a steel front clusterpin bushing, and thus eliminating the backlash.
The 904 yoke takes 7260 U-joints that don't take much torque to shatter.

Opinion coming
The gear ratio splits in that od box, are
IMO
lousy for a warmed up SBM
They are fine for a lo-po, low-rpm engine, or a hi-torque engine
The ratios are;
3.09-1.67-1.00-.73od, with splits of .54-.60-.73
So when you outshift first into second, the rpm falls to .54. Shifting at 2800, the Rs fall to 1512, so your engine better have some grunt down there. .. Shifting at 5600 the Rs will fall to 3024 so your cam will have to be selected for a powerband of 3024 to 5600=2576; good luck with that.
If you gear your car for use in Second gear, low gear will be borderline outrageously lo: I like Second gear to be my go-to gear, so about 6.80 overall. This makes 35mph to be 3000 rpm ready to rock with a hi-torque engine.
With the od box , 6.80 /1.67=4.10s in the back. This makes your starter gear to be 4.1 x3.09=12.67; borderline ridiculous.
My combo never liked it no matter what rear gears I ran.
Maybe you will have better luck.

Like I said, it does work well with a lo-rpm torque-monster. And you just know that with a 4.125 stroke, the 225 does really well on the bottom.

Jus my opinions.
 
You can change the front bearing retainer for the smaller size. I have an od trans and big block bellhousing. I got the new bearing retainer online with the 4.8 register for the bellhousing
 
You can change the front bearing retainer for the smaller size. I have an od trans and big block bellhousing. I got the new bearing retainer online with the 4.8 register for the bellhousing
Ok, pretend I know nothing. Your saying I can change the front bearing retainer from 5.125 to something smaller? this is easy? Once done i can use a more common bellhousing?
 
Ok, pretend I know nothing. Your saying I can change the front bearing retainer from 5.125 to something smaller? this is easy? Once done i can use a more common bellhousing?

Yes, you can switch the input bearing retainer from one that’s 5.125” to one that’s 4.8”. But you have to remember that there are two different 4.8” diameter input bearing retainers, one has a smaller bolt pattern (307 bearing). The one you need is the 4.8” diameter retainer that came with the 308 input bearing and has the larger bolt pattern.
 
Yes, you can switch the input bearing retainer from one that’s 5.125” to one that’s 4.8”. But you have to remember that there are two different 4.8” diameter input bearing retainers, one has a smaller bolt pattern (307 bearing). The one you need is the 4.8” diameter retainer that came with the 308 input bearing and has the larger bolt pattern.
now that makes sense. thank you.
 
I have a 833od behind my 340 and I hate it. Shifting up is hard, shifting down is really hard and the OD gear is noisy. I can hit 60 in 2nd gear with 3.55 rear. and first is only good up to 30. I may have gotten a bum OD, but nun the less I am switching back to a standard 833.
 
Yes, you can switch the input bearing retainer from one that’s 5.125” to one that’s 4.8”. But you have to remember that there are two different 4.8” diameter input bearing retainers, one has a smaller bolt pattern (307 bearing). The one you need is the 4.8” diameter retainer that came with the 308 input bearing and has the larger bolt pattern.

Yes ^^^^^ as said above. I just measured the bolt pattern and ordered the one I needed. I got mine from Brewer's Performance. They have all of them in stock.
 
I have a 833od behind my 340 and I hate it. Shifting up is hard, shifting down is really hard and the OD gear is noisy. I can hit 60 in 2nd gear with 3.55 rear. and first is only good up to 30. I may have gotten a bum OD, but nun the less I am switching back to a standard 833.

That’s not an “overdrive” problem. That’s a hammered, busted transmission problem. In proper working order an 833 OD has none of those issues.
 
Isn't the OD trans just have the 3rd and 4th gears flipped essentially in some way?
 
Isn't the OD trans just have the 3rd and 4th gears flipped essentially in some way?

Yes, the overdrive gear actually sits in the normal 3rd gear location, and the shift levers are flipped.

Because of that when the transmission is in overdrive there’s more force going back into the shafts (since it’s not a “direct drive” gear), which is why the larger bearing retainer was used. And the rollers between the input and output shafts get more wear because the shafts aren’t locked together by the collars like they normally would be in the 1:1 fourth gear.

Way better info on all of that here
4 Speed Transmissions transmission

A lot of people dog on the strength of the overdrive transmissions. They’re not quite as strong as the standard 833, but they’re still plenty strong enough. And they can be strengthened, you can bush the shafts in the case to improve their strength (or remove shaft play if the case is worn).
 
I have a 833od behind my 340 and I hate it. Shifting up is hard, shifting down is really hard and the OD gear is noisy. I can hit 60 in 2nd gear with 3.55 rear. and first is only good up to 30. I may have gotten a bum OD, but nun the less I am switching back to a standard 833.
If yur buying, choose a Commando 3.09-1.91-1.40-1.00
If you wanna fix the slow-shifting, I know the cure for that, PM me
But the best Idea is really to get rid of that box, the splits as you have found out, are really far apart.
 
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Isn't the OD trans just have the 3rd and 4th gears flipped essentially in some way?
No silly, the 3-4 lever is flipped so you can shift a regular H-pattern, but the guts inside the box are almost 100% different.
About the only parts you can swap to a regular box is/are
the 1-2 synchronizer assy,
and maybe the Mainshaft first gear,
and maybe the 3-4 slider,
and of course the brass..
The Low-gear tooth count is the same as in the regular box, but I haven't tried it, to see if they mesh. But no big deal cuz in over 50 years, I have never replaced a first gear,lol.
 
If yur buying, choose a Commando 3.09-1.91-1.40-1.00
If you wanna fix the slow-shifting, I know the cure for that, PM
But the best Idea is really to get rid of that box, the splits as you have found out, are really far apart.

There’s nothing wrong with the 833 OD transmissions. It just depends on the application, just like everything else. For a stock to mild performance engine the splits are wide, but they’re not unmanageable. And for a street car that sees freeway time the utility of the overdrive gear is hard to beat, especially for the price you can usually pick the 833OD’s up for.

If you’ve got a high winding small block car that sees mostly strip time they’re the wrong choice for sure. But that doesn’t sound like application of this particular car.

Besides, if you’ve built some high winding small block for track use you probably have the money for something else in the transmission department. But for a street car on the cheap an 833OD can be pretty handy. Not everyone can afford to drop $3k (or more) on a gear vendors or a 5 or 6 speed.

The splits aren’t any worse than most of the cars that came with 3 speed manuals, people made those work just fine for decades. Hell the NP435 in my ‘71 Ford F100 goes 6.68, 3.34, 1.66 and 1:1, talk about wide splits. I drive it like a 3 speed ignoring granny low, and I put a decent number of miles on that truck every year too. Are there transmissions with better splits than that? Absolutely. But it works just fine the way it is too, and a lot of people love the hell out of those NP435’s.
 
Just an FYI- those SB OD bell's were also made with NO casting number.

The one I have just has a series of blank rectangles.
 
There’s nothing wrong with the 833 OD transmissions. It just depends on the application

I ran that A833od for 4 years, and know exactly what @trapster means in post 13.
I took it apart and fixed it, then it broke
I bought another cuz yur right, they are cheap. It broke too.
I bought another, and it broke too.
But the whole time I had one, the splits were horrible, like I keep saying, for anything but a hi-torque AND low-rpm engine.
I bought the GVod, to use it as a splitter, thinking that was gonna be pretty good. with ratios of
3.09-2.41-1.67-1.30-1.00-.78-.57; GV in red..yes seven useable ratios. and splits od .78-.69-.78.77-.78-.73
Butum, I was wrong. It was fine when upshifting, but the GV is not made to be downshifted into. And I got tired of having to work around the wide splits again. And honestly; seven ratios was 2 too many.
So I got the Commando.
3.09-1.92-1.40-1.00.. And split it with the GV, for ratios of;
3.09-2.41-1.92-1.50-1.40-1.09/1.00-.78; EIGHT ratios now, but I only use five of them; different gears at different times. Most of the time as a regular 4+1.
And I have not been able to break the Commando.
Now, that 367 engine of mine, at that time, was running a 223@.050 cam, and 11/1 Scr with pressure of 185psi. So it was a nice hi-torque engine with a powerpeak not much higher than the old 340.. but with more pressure than the 340, and 27 more cubes. So when I say I didn't like it, yes, that's my opinion. But with open-chambered iron heads, you'd be hard pressed to run more than 160 psi at full timing, so it's gonna be worse. If you marry that to a slow shifting box,behind a 340,with 3.55gears..... I can guarantee that it will be frustrating.
Mine STOPPED being frustrating after
I installed the GVod AND
4.30 gears, and
converted the od box to slick-shift, and
learned how to split-shift.
That's a lot of dedication to trying to make the crappy splits work. Almost $4000 worth of dedication. So I'm not real excited to be lectured at. It's a good thing those overdrive boxes were so dirt-cheep, making the whole exercise a lil less frustrating.
Oh and after breaking three of those boxes, in various ways, I was just ....... done with the whole dumb idea I had had. The ratios are just too far apart;
the whole time I had one, the splits were horrible, like I keep saying, for anything but a hi-torque AND low-rpm engine.
And that is my opinion.
and I will never change it.
And shoot; I can break that weakazz 20tooth mainshaft overdrive gear, in a heartbeat. Zing, here we go again; when it breaks, the shattered pieces do not just fall to the bottom........
 
I'm running an 833 OD behind a '69 440 with a mild cam upgrade, in a 1980 short bed D100.

No issues.

Not a daily or even weekend driver but when it does got driven, it gets some thrashing.

Kinda hard not to.

I've been told by members on FxBO that the splits are the same as an NP 3 speed, and we all know 340 and 383 HP cars came with those from the factory.

The difference is that the common shift on the OD is across the gate whereas on the 3 speed it's on the same side.
 
Not to go on too far of a tangent, does anyone know of a flywheel for 400 big block that is externally balanced other than McLeod? Would the externally balanced 360 flywheel bolt up?
 
Not to go on too far of a tangent, does anyone know of a flywheel for 400 big block that is externally balanced other than McLeod? Would the externally balanced 360 flywheel bolt up?
360 is different. We have 400 externally balanced wheels in both 10.5" and 11".
 
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