Someone Please Explain Torque Converters (And How to Pick the Right One)

[AngryMcMuffin]

I'll start by saying that I've tried searching, and there are a lot of results, but I typically don't touch automatic transmissions in any case where it can be avoided, so this is a new venture for me.

I have made the key information in this post bold as a sort of TLDR;

Car has been fighting me at every turn, but I just got my Transgo AOD-HP shift kit installed. Well, the valve body part so far, car feels a lot better, though I wish I had opted for 'even more firmness' between 1-2 shifts. Maybe later on.

However, To install the new parts for the governor and whatever the two seals on the front of the trans are that the kit describes, I've gotta pull the AOD, and regrettably, put it back in the car.

This means I should put a non-stock torque converter in while the trans is out. What brand/stall are you all running with what setups?

1987 Grand Marquis.
Car has Explorer intake and TB, AFR 165 heads, TFS1 cam, 1.6 Scorpion rockers, stock Lopo bottom end, and if I remember correctly, 3.27 gears (been a few years, does this sound right?).
Operating range for the cam is listed as 2000-5500rpm.

I'm not looking at re-gearing yet, though I know that'll be something to consider in the future when I start caring about having fun running from redlight to redlight in this one, my 1999 BMW 540i (factory V8) 6 speed already does that really well, if it decides to actually ever hook, and still pulling in 5th at 160mph.

Use case will mainly be cruising, sounding cool, and probably interstate pulls in the 60-130ish range. With a few runs down our local 1/8th mile, purely for fun.

Just looking for advice on what brand, size(?), and stall might make me not hate the car being an auto, as much as I'd love to T5 swap it, I just want the car to work, work well, and not grenade the AOD for hopefully a couple years.

There are other things I'm still working on, but would like to go ahead and get the part for when I get to pull the trans out, as I intend to daily drive the car for at least a month or two while I replace the clutch in my actual daily.

I DO NOT CARE ABOUT NVH or really anything comfort/noise related when it comes to the drivetrain. Though, it would be nice to be aware of before purchasing anything.

[gadget73]

the governor does not require removal of the trans. The tailshaft housing has to come off but thats it. The gov lives just forward of where the speedo cable goes in. Not sure what seals they want changed, off the top of my head the only thing I can think of up front would be something related to the pump itself.

If you pull the governor just make sure you put it back on the correct way. It basically will install either direction but only functions one way.

[AngryMcMuffin]

the governor does not require removal of the trans. The tailshaft housing has to come off but thats it. The gov lives just forward of where the speedo cable goes in. Not sure what seals they want changed, off the top of my head the only thing I can think of up front would be something related to the pump itself.

If you pull the governor just make sure you put it back on the correct way. It basically will install either direction but only functions one way.

I have read to just jack the rear up, so you don't lose all your trans fluid when you remove the tailhousing to get to the shift governor.

But I did look at the instructions again while I was with the car last night, and they're talking about the Pump Stator. The instructions did say 'over 300HP' to do that, because apparently stock seals won't last with the higher line pressures. I'm imagining they mean crank, and I figure I'll be in the neighborhood once I get the car tuned right. So, it's more of "better safe than sorry" thing for me. Along with the torque converter question.
And since the trans has to come loose to change the converter, I figured it'd be wise to do all at the same time.

I've burned up a TH350 and a 700r4 behind a Chevy 307 that was stock besides a 4bbl intake and true dual exhaust, so I'm just trying to not repeat that. Granted, 1/4 mile long power brake burnouts on a hurt transmission are what did it in the last time. This car won't see abuse like that until I'm ready to replace the trans.

[gadget73]

ok pump stator seals makes sense, there just isn't very much up there.

I blew up a 4L60E (electronic 700R4) behind a bone stock 4.3 V6 in a Chevy S10 by backing out of my driveway. I wouldn't really rely too heavily on that as a predictor of AOD longevity but an old high mileage one with extra hp in front of it is probably not going to survive a long time in stock form. I have one behind an HO with 230k on it that works fine, but most of them have not been anywhere nearly so fanatically maintained. I did put a shift kit in there but that was more about swapping to a known working valve body to fix a sticking forward clutch than anything else. The spare VB I had just happened to have a regular Transgo kit in it.

anyway, I have a stock converter in mine so I don't have a lot of specific advice for you. There are two basic types though, lockup and non-lockup. The AOD doesn't exactly have a lockup torque converter like basically everything else has, it actually bypasses the converter entirely and drives the inner shaft directly from the converter shell in 3 and 4. The non-lockup converters just have a two-step spline on the turbine inside that drives both shafts from the turbine instead of one from the turbine and one from the shell. This does make more heat and costs some fuel economy but it will improve performance a little in 3rd. Make sure you have a stout cooler if you go this route or it will cook itself. You really ought to have a cooler anyway.

also might want to consider an upgraded inner input shaft. it just slides out. Bare minimum, pull it and grind an X across the transmission end. If things wear a bit in there, the shaft will bottom out and plug an oil passage which will trash the planetary set. The grinder notch will keep that oil passage from being blocked off.

[Brown_Muscle]

Sounds like a 2200-2500rpm stall torque converter would work well for your application, similar to what I have. I'd link you to what i got a few years ago but apparently they are discontinued. I'd get a lockup style one, and like Gadget said, the hardened input shaft. They are easy to snap when you're putting out decent power.

[AngryMcMuffin]

Heard that heard that. I guess I'll be rocking the stock for a little longer than anticipated, because I didn't factor in an input shaft into my imaginary "budget" yet.

I had understood that the input shaft is good up to around 350hp. Maybe it's just the amount of time I've spent on Miata and RX7 forums, but is that reference to wheel or crank horsepower? As on the foreign car forums it's always safe to assume they're only talking about WHP and WTQ figures.

I forget the details about the failure points in AODs, as it;s been three years since I was reading up on it.

[P72Ford]

I would have a custom converter built, but in order to do that you need to nail down the rear gear. The difference from a converter standpoint from 3.27 to 3.73 in a heavy car is very significant. The reason I mention 3.73, is because I think its a pretty ideal compromise for a heavy car that you want to accelerate and still behave on the highway.

These guys are right about the input shaft; a must have if you are going with a lock-up converter.

Many moons ago I had Alan at Dirty Dog build me a 3600 stall non lock up converter for the AOD in my coupe. 302, GT40P heads, 600 DP/ Air Gap, 3.73s. The car was a riot for such a mild build. I will say the converter and Silverfox valve body were a great combo. In retrospect I would have done a lock up converter, but I was too cheap to pull the transmission and do the input shaft when I was going through the car. Despite the 3600 stall speed, the car still drove great. You could footbrake to about 3200, and it would flash to 3400ish with the pedal on the rug.

[AngryMcMuffin]

I would have a custom converter built, but in order to do that you need to nail down the rear gear. The difference from a converter standpoint from 3.27 to 3.73 in a heavy car is very significant. The reason I mention 3.73, is because I think its a pretty ideal compromise for a heavy car that you want to accelerate and still behave on the highway.

These guys are right about the input shaft; a must have if you are going with a lock-up converter.

Many moons ago I had Alan at Dirty Dog build me a 3600 stall non lock up converter for the AOD in my coupe. 302, GT40P heads, 600 DP/ Air Gap, 3.73s. The car was a riot for such a mild build. I will say the converter and Silverfox valve body were a great combo. In retrospect I would have done a lock up converter, but I was too cheap to pull the transmission and do the input shaft when I was going through the car. Despite the 3600 stall speed, the car still drove great. You could footbrake to about 3200, and it would flash to 3400ish with the pedal on the rug.

Word word, I'm thinking about this Boss Hog converter the lady at Summit reccomended actually: https://www.summitracing.com/parts/ape-26422

I finally got the car driveable and after nearly 300 miles, that stall range seems appropriate with where the engine seems to have power come on. Definitely the stock shift governor keeping me from hurting the trans right now.