Gear Vendors on a A833

[matthon]

What exactly is the A833OD. Is that a factory Chrysler.

Yes sir.
Made in cast iron and aluminum case for a-bodies, iirc just cast iron for b-bodies.

Have a 76 cast iron one in my a-body, a cast iron one on the way for my b-body.

Forgot to mention, need to get the correct 3/4 arm and rod for the shifter.

These are not the Chrysler truck trans or the GM A833, yes GM Chrysler A833, that have a different trans to bell bolt pattern.

If interested:

 

[kreauto]

I bought 3 Passion hemi overdrives. Put one in my 440 6pac cuda with 410 gears. Overdrive is very nice now in that car however it is like driving a three speed with overdrive. I’m not sure I would like it as good with 3.23 gears. That said I put one in my 66 Satellite that was a original three on the tree 273 stock engine with 2.76 gears and you just can’t get a better quieter and driving car. Torque is great down low and unlimited high speed cruising. The third is for a 73 Duster 340 currently original floor shift auto with 3.23 gears. Can’t get myself to switch the most original car I own. Have fender tag 2 build sheets original engine and trans and rear.

 

[HawkRod]

I installed a Gear Vendors overdrive for my 73 Road Runner 340 (416 stroker) with a 727 automatic.

The unit works the same regardless of if it is installed on an automatic or a manual transmission. You can put it in manual mode, and every time you push (or press with your foot) a switch, you engage or disengage the overdrive. This way, you can shift to first gear, first overdrive, second, second overdrive, etc.

The auto mode engages the overdrive whenever you reach a speed of about 47 MPH, regardless of gear (with an automatic, this is almost always third).

I found that the manual mode sucks. Too much going on, and it is really hard to time hard acceleration shifts to optimize acceleration. So the whole idea of a four speed becoming an 8 speed is BS. You'll never use it.

BUT, the unit is strong as hell, and it does work very nicely as an overdrive. Yes, it is "only" .78 to 1, but I found with my 3.55 rear it worked very nicely. I always left it in auto mode and I was happy with it. My 70 Road Runner has a .70:1 overdrive, so it is a more "steep" overdrive, but the GV worked OK with my 3.55 rear in my 73.

Installation: "You need to just dent a few spots on the transmission tunnel to install the GV." BS. I had to significantly bash/modify my tunnel to make it fit nicely.

Bottom line: Once it is installed, it worked very nicely. The reality for me is I left it in auto and used it as a highway overdrive.

Other options are to convert a A833 to an overdrive (Passon Performance does this), but then you end up with 3 gears and OD (I've done this too, and it works well). If you ask me about a choice between a A833 and GV, or a Passon Oberdrive built into an A833, I'll pick the GV OD. It gives you "standard" performance with the four speed plus an extra gear. The Passon setup works well, but you get one fewer gear and about the same OD gearing.

The only other option is a Tremec TKX. Good gearing and a 5 speed, but then you have to cut your transmission tunnel to fit the shifter and that has its own set of issues.

Hope some of this helps...

 

[andrewwoz]

Bottom line: Once it is installed, it worked very nicely. The reality for me is I left it in auto and used it as a highway overdrive.

Other options are to convert a A833 to an overdrive (Passon Performance does this), but then you end up with 3 gears and OD (I've done this too, and it works well). If you ask me about a choice between a A833 and GV, or a Passon Oberdrive built into an A833, I'll pick the GV OD. It gives you "standard" performance with the four speed plus an extra gear. The Passon setup works well, but you get one fewer gear and about the same OD gearing.

The only other option is a Tremec TKX. Good gearing and a 5 speed, but then you have to cut your transmission tunnel to fit the shifter and that has its own set of issues.

Hope some of this helps...

Any chance you have any photos of the tunnel massaging you did for the GV? I have been mostly happy with the Passon OD trans but have been missing have 4 regular gears around town and have been keeping an eye out for a regular hemi transmission.

Also, have you ever driven a manual trans with the GV? I recall someone saying engagement is a bit more harsh than with an auto.

 

[YY1]

Its going to depend on final drive and tire size but it should be more than 200rpm, example in photos below.

Another option is the Passon Hemi OD trans. I currently am running one of these and have been mostly happy with it. With every option it seems like there is a compromise, TKX is big $$ and involves some cutting but seems like the best option from a functionality point, passon hemi OD is less expensive and requires no cutting but the RPM drop from 1-2 and 2-3 is noticeable over a standard a833. Gear vendors is I believe the least expensive option but might require a little cutting still. Also, I believe in addition to the activation via button there is an option to automatically turn it off below a certain speed, but I may be wrong.

View attachment 1958055View attachment 1958056

Is that the unit they redid the gear ratios on to match a 727?

I'm running an 833 OD and find I have to do a LOT of cross gate 2-3 3-2 shifting.

Wondering if the new ratios help this.

By chance is there a comparison of the std 833 and Passion Hemi OD ratios?

 

[Mackman]

Any chance you have any photos of the tunnel massaging you did for the GV? I have been mostly happy with the Passon OD trans but have been missing have 4 regular gears around town and have been keeping an eye out for a regular hemi transmission.

Also, have you ever driven a manual trans with the GV? I recall someone saying engagement is a bit more harsh than with an auto.

Engagement is plenty harsh WITH an auto.

 

[RR Fan Dan]

By chance is there a comparison of the std 833 and Passion Hemi OD ratios

What gears with OD A-833?

Not exactly what you are looking for but close.

 

[ckessel]

800 rpm drop is HUGE.
My rpm at 70 mph used to be 3,100 with the 727. Switching to a TKX with a .81 O/D it dropped to about 2,400 rpm.

That 700 rpm drop makes a massive difference, to noise, mpg and mechanical wear. Heck, even 500 rpm is significant. Ask others who've done similar swaps e.g. @Kern Dog

I had a 300rpm drop just going to 255/70-15 tires[ 28.94"] from the 215/70-14's[ 25.75"] with my 3.23's. I do plan on a GV behind the 727 in the future.

 

[RR Fan Dan]

How did that affect the acceleration going to a taller tire?

I had a 300rpm drop just going to 255/70-15 tires[ 28.94"] from the 215/70-14's[ 25.75"] with my 3.23's. I do plan on a GV behind the 727 in the future.

 

[matthon]

800rpm drop is definitely huge.
My daughter and I can have an actual conversation, hear each other, and don't have to crank the radio so much, but we still do.

Fwiw, in my case, going to the OD and a slightly taller tire increased acceleration, most likely due to the OD 1st gear.

 

[ckessel]

How did that affect the acceleration going to a taller tire?

It's slower since the overall gear ratio changed. No big deal as the wagon is a cruiser and I am more interested in cutting the rpm when on the road.

 

[YY1]

What gears with OD A-833?

Not exactly what you are looking for but close.

Yeah, I was looking for the Passon Hemi OD vs the standard 833 OD.

Thanks, though.

 

[RR Fan Dan]

Yeah, I was looking for the Passon Hemi OD vs the standard 833 OD.

Thanks, though.

What’s the difference in the two? Passion sells both.

 

[YY1]

What’s the difference in the two? Passion sells both.

That's what I want to know.

Previously, I had read that Passon was working on a manual trans with the same gear ratios/spread as a 727.

Not sure if that ever made it to production.

 

[YY1]

BTW "miraculously" a member has listed an 833 OD for sale, just a few minutes ago.

 

[matthon]

Here's what I did for my a-body, plan on the same for my b-body.

To swap from the regular A833 to the A833OD:
On the OD turn down the bearing retainer from 5.125 to 4.805.
Have/get a bell with the 4.805 hole.
Verify runout and get appropriate offset dowel pins.
Get the OD 3/4 shifter arm and rod.

On a b-body, may be able to just flip the existing 3/4 rod. I've been told this works on the forums, doesn't work from someone who actually did it. Maybe specific to model/year.

To swap back to the A833:
Have/swap a 4.805 bearing retainer to the standard A833, or use a ring on a 4.354 retainer.

 

[andrewwoz]

Is that the unit they redid the gear ratios on to match a 727?

I'm running an 833 OD and find I have to do a LOT of cross gate 2-3 3-2 shifting.

Wondering if the new ratios help this.

By chance is there a comparison of the std 833 and Passion Hemi OD ratios?

Yeah, its actually just the complete trans they sell. I dont do a ton of gear hunting between 2-3 but the stroker might help with that some, its pretty happy anywhere about like 1800rpm.

Passon ratios are
2.66
1.59
1.0
0.8

OEM OD ratios are
3.09
1.67
1.00
.73