Transmission Options

[T. Fritz]

Hello all, its been a while since ive posted in this forum, but! I have a 70 Duster with a 340 bored and stroked to about 422ci and currently a cast aluminum case a833od trans behind it. The engine has way more power than that tranny can handle as ive already broken it once but had it repaired to get me through the rest of the season. But now im looking into getting a trans that should hold up to the unknown amount of torque and horsies this engine has to offer. Ive read several threads about possible Hemi OD trans from Passon Performance as well as possibly a Tremec TKX 5 speed swap and frankly im not favoring either one of them for differing reasons. Are there any other options for us A body guys out there other than just a normal A833? Id prefer to have that OD gear if possible as I plan to drive my car when I can trust it enough.

Thanks.

 

[Dave999]

B body A833 with a gear vendors on the back
expensive
gets you your overdrive without cutting the cross member
need to address stick position problems tailshaft problems and potentially clearance the tunnel further back with a big hammer
i only know this cos someone here did it. read it all he had numerous trials

New build A833 18 spline with Gear Vendors OD.

the only tremec i have seen that you can fit to an A without cutting the crossmember out was the never very strong TR 3550 box provided by keisler
it had the mid shift tower machined flat to make space for the cross member and worked with a standard bell and 1/4 inch steel adapter.
but still needed a new hole for the shifter and the front of the tunnel slit expanded and patched

it would not be good behind your motor in the same way a t5 would not be good behind your motor tko or tkx might be but both involve surgery as i belive you have already recognised in your post

Dave

 

[Newbomb Turk]

Hello all, its been a while since ive posted in this forum, but! I have a 70 Duster with a 340 bored and stroked to about 422ci and currently a cast aluminum case a833od trans behind it. The engine has way more power than that tranny can handle as ive already broken it once but had it repaired to get me through the rest of the season. But now im looking into getting a trans that should hold up to the unknown amount of torque and horsies this engine has to offer. Ive read several threads about possible Hemi OD trans from Passon Performance as well as possibly a Tremec TKX 5 speed swap and frankly im not favoring either one of them for differing reasons. Are there any other options for us A body guys out there other than just a normal A833? Id prefer to have that OD gear if possible as I plan to drive my car when I can trust it enough.

Thanks.

The clutch is breaking your gearbox. You can put a different gearbox in it. If the clutch doesnt break that one, it will find the next weakest part and kill it.

You need to address the clutch issue. You either need an adjustable clutch or you need a clutch tamer.

You can keep spending money on parts you will break or you can address the clutch.

 

[T. Fritz]

B body A833 with a gear vendors on the back
expensive
gets you your overdrive without cutting the cross member
need to address stick position problems tailshaft problems and potentially clearance the tunnel further back with a big hammer
i only know this cos someone here did it. read it all he had numerous trials

New build A833 18 spline with Gear Vendors OD.

the only tremec i have seen that you can fit to an A without cutting the crossmember out was the never very strong TR 3550 box provided by keisler
it had the mid shift tower machined flat to make space for the cross member and worked with a standard bell and 1/4 inch steel adapter.
but still needed a new hole for the shifter and the front of the tunnel slit expanded and patched

it would not be good behind your motor in the same way a t5 would not be good behind your motor tko or tkx might be but both involve surgery as i belive you have already recognised in your post

Dave

So it sounds like im limited to either cutting up my floor, use a non OD A833, or take the risk with Passon

 

[Newbomb Turk]

So it sounds like im limited to either cutting up my floor, use a non OD A833, or take the risk with Passon

Or fix your clutch issues.

 

[jbc426]

Hello all, its been a while since ive posted in this forum, but! I have a 70 Duster with a 340 bored and stroked to about 422ci and currently a cast aluminum case a833od trans behind it. The engine has way more power than that tranny can handle as ive already broken it once but had it repaired to get me through the rest of the season. But now im looking into getting a trans that should hold up to the unknown amount of torque and horsies this engine has to offer. Ive read several threads about possible Hemi OD trans from Passon Performance as well as possibly a Tremec TKX 5 speed swap and frankly im not favoring either one of them for differing reasons. Are there any other options for us A body guys out there other than just a normal A833? Id prefer to have that OD gear if possible as I plan to drive my car when I can trust it enough.

Thanks.

I heard the case aluminum case 833's were not as strong at the cast iron case ones. What was the failure point on your transmission when it broke last time. I've been running close to 700hp with a big block through my 833 and Passon 5 speed without breakage.

 

[T. Fritz]

It broke one of the mounting ears off where the trans meets the bell housing.

 

[72bluNblu]

You do know that you can put the guts from an 833OD box into a cast iron case right?

Although, breaking the ear off the case doesn't sound like a transmission problem to me. That sounds a lot more like a chassis/driveline mounting issue than a transmission problem.

 

[T. Fritz]

You do know that you can put the guts from an 833OD box into a cast iron case right?

Although, breaking the ear off the case doesn't sound like a transmission problem to me. That sounds a lot more like a chassis/driveline mounting issue than a transmission problem.

Dually noted. I'll look into the rest of the driveline while im at it. And yes the clutch too

 

[AJ/FormS]

So it sounds like im limited to either cutting up my floor, use a non OD A833, or take the risk with Passon

Or just run a Commando-A833, with say a 2.94 rear gear, and learn to use the clutch. (I installed a GVod behind my Commando, .78 od.)
A 2.94 and 27s will get you 65=2400, and it get's hard enough to get full cruise timing at 2400, never mind any lower than that.
Your engine might want 56 Degrees for cruising; IDK. But, if you don't give her what she wants, she cannot make fuel economy to her true potential.
Some days, my 367 wants up to 60 degrees. One time, she made best fuel economy at 63*!
Cruising at a lower rpm, say 1800, with not nearly enough timing will kill fuel economy faster than, say 2400 with the right timing. I know, cuz I've tried it all.
I currently cruise at 65=2240, at optimum timing, cuz that's the lowest rpm that my cam wants to spin, and I can just make 55* there..
>>Figure out your lowest rpm, then gear your car to do it. With a 422, you should have a preponderance of low-rpm torque already, so 2.94s on the street should not be a problem.
The only difference between a Commando box and the regular box, is the first gear ratio.
Here are the ratios;, the Standard first
2.66-1.92-1.49-1.00
3.09-.192-1.49-1.00
Here would be your roadgears with the Commando, and 2.94s
9.08-5.64-4.12-2.94. What's not to like?! Your A833od, with 3.55s wouldda been
10.97-5.93-3.55-2.59
Notice the similar Second gears, and even Thirds are not that far apart. Obviously, with 3.73s your cruise-rpm would have been too low; at 65=2100, for best fuel-economy.
I just guessed at your rear gears.

The Commando is better in every way.
>> Now, go back to the 2.66box, add the GVod, and switch to 3.73s, and watch this;
9.92-7.16-5.22-4.07*-2.91 Badaboom. *This is shifting into overdrive, using the the GVod as a gear-splitter, after third, and then finishing in 4od. This gives you a short fourth, and a deeper overdrive. The splits are .72-.73-.78-.71od

If you want to drive a little slower, then keep the Commando ( I would). This would change nothing but yur starter gear, from 9.92 to 11.53, and 600rpm in-gear and idling could get you down to 4.2mph.
If yur cam is small enough, 550 rpm would be 3.8mph and now you can parade the beast. yet still cruise the hiway at 65=2350.

BTW
Passon will sell you a HD alloy case, and the guts of any A833 should fit in there. My Commando gears dropped in no fuss.
And/or, my Commando gears also fit into the standard FMJ alloy housing, which I had been running previously. Boy! that' alloy case is a game changer when hoisting that thing up into the tunnel.
Ok so those are sumore options.

> BTW -2
my engine makes enough Power to go 93 in the Eighth. so, she's no slouch. She's broken two overdrive gears, but never a case, nor anything else, in the trans.
But man, she's hard on clutch discs.

 

[matthon]

A833 OD iron case here with a healthy 383.

Swapped out my A833 for long hauls and won't be swapping it back.

The Mopar 5 speed is defunct, the Hemi OD gear set is made by the same company, which took down their website over a year ago.

A833 Swap to A833 OD

 

[72bluNblu]

Or just run a Commando-A833, with say a 2.94 rear gear, and learn to use the clutch. (I installed a GVod behind my Commando, .78 od.)
A 2.94 and 27s will get you 65=2400, and it get's hard enough to get full cruise timing at 2400, never mind any lower than that.
Your engine might want 56 Degrees for cruising; IDK. But, if you don't give her what she wants, she cannot make fuel economy to her true potential.
Some days, my 367 wants up to 60 degrees. One time, she made best fuel economy at 63*!
Cruising at a lower rpm, say 1800, with not nearly enough timing will kill fuel economy faster than, say 2400 with the right timing. I know, cuz I've tried it all.
I currently cruise at 65=2240, at optimum timing, cuz that's the lowest rpm that my cam wants to spin, and I can just make 55* there..
>>Figure out your lowest rpm, then gear your car to do it. With a 422, you should have a preponderance of low-rpm torque already, so 2.94s on the street should not be a problem.
The only difference between a Commando box and the regular box, is the first gear ratio.
Here are the ratios;, the Standard first
2.66-1.92-1.49-1.00
3.09-.192-1.49-1.00
Here would be your roadgears with the Commando, and 2.94s
9.08-5.64-4.12-2.94. What's not to like?! Your A833od, with 3.55s wouldda been
10.97-5.93-3.55-2.59
Notice the similar Second gears, and even Thirds are not that far apart. Obviously, with 3.73s your cruise-rpm would have been too low; at 65=2100, for best fuel-economy.
I just guessed at your rear gears.

The Commando is better in every way.
>> Now, go back to the 2.66box, add the GVod, and switch to 3.73s, and watch this;
9.92-7.16-5.22-4.07*-2.91 Badaboom. *This is shifting into overdrive, using the the GVod as a gear-splitter, after third, and then finishing in 4od. This gives you a short fourth, and a deeper overdrive. The splits are .72-.73-.78-.71od

If you want to drive a little slower, then keep the Commando ( I would). This would change nothing but yur starter gear, from 9.92 to 11.53, and 600rpm in-gear and idling could get you down to 4.2mph.
If yur cam is small enough, 550 rpm would be 3.8mph and now you can parade the beast. yet still cruise the hiway at 65=2350.

BTW
Passon will sell you a HD alloy case, and the guts of any A833 should fit in there. My Commando gears dropped in no fuss.
And/or, my Commando gears also fit into the standard FMJ alloy housing, which I had been running previously. Boy! that' alloy case is a game changer when hoisting that thing up into the tunnel.
Ok so those are sumore options.

> BTW -2
my engine makes enough Power to go 93 in the Eighth. so, she's no slouch. She's broken two overdrive gears, but never a case, nor anything else, in the trans.
But man, she's hard on clutch discs.

Did you miss the part where the issue with the transmission was a broken ear on the case?

Has nothing to do with the gears or shafts at all. And yeah, you can put an 833OD gear set into a cast iron case. If the case is even the issue with that particular problem.