Visual differences between AOD and C4 torque converter

[hyghlndr]

Hi, trying to find the torque converter correct for a AOD transmission. The shelf is loaded with more than a dozen, most I am told are from c4s. Any way to tell visually?? If not best suggestion for a new/rebuilt one for a AOD going behind a newer 302/ 1990's 5.0?

 

[Broncobowsher]

I don't know an external way to tell them apart.
I know internally that AOD has 2 sets of splines driving 2 separate input shafts (outer is driven off the turbine for 1st and 2nd gear as well as 40% of 3rd gear. The inner shaft bypasses the turbine and is driven from a sprung hub from the front shell of the convertor to power 60% of 3rd gear and all of overdrive.
All other convertors only have one set of splines. Well there is that oddball ATX transaxle that has a planetary gear set inside the convertor, but I don't see that getting mixed up as it won't have a matching bolt circle.

 

[hyghlndr]

I don't know an external way to tell them apart.
I know internally that AOD has 2 sets of splines driving 2 separate input shafts (outer is driven off the turbine for 1st and 2nd gear as well as 40% of 3rd gear. The inner shaft bypasses the turbine and is driven from a sprung hub from the front shell of the convertor to power 60% of 3rd gear and all of overdrive.
All other convertors only have one set of splines. Well there is that oddball ATX transaxle that has a planetary gear set inside the convertor, but I don't see that getting mixed up as it won't have a matching bolt circle.

Thanks, would there a way to see the difference down inside the "snout" of the torque converter?

 

[Broncobowsher]

Thanks, would there a way to see the difference down inside the "snout" of the torque converter?

I would expect so, but have never done it. May be obscured by fluid sitting in the convertor as well.
I'm not even sure where to look for part numbers. If you see one, AOD started in '80 so the engineering code should start with E0 or newer as revisions happened.
I also have zero idea what varients and revisions exist for the AOD either. I know of the AOD, I do my best to avoid the AOD.

 

[hyghlndr]

For future reference, looking down inside of an aod converter snout you will see three sets of spline rings. A c4 will only have two.

 

[Broncobowsher]

I was only thinking of driving splines, forgot to add the stator splines. Counts are correct and make sense.