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I have a '68 302 4v C4 auto cougar. Its going to be my daily driver when I get my license in a few months. The C4 transmission in the car now works just as it should except its a pain to drive around because it only goes up to 3rd gear. I want to swap it out for a AODE trans from like a 80's or 90's crown vic or grand marquis, so it'll keep the RPM's down on the highway and be more enjoyable to drive. So my question is, will this transmission bolt right on to my 302 engine?

Much appreciated, Nate B
 

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I have a '68 302 4v C4 auto cougar. Its going to be my daily driver when I get my license in a few months. The C4 transmission in the car now works just as it should except its a pain to drive around because it only goes up to 3rd gear. I want to swap it out for a AODE trans from like a 80's or 90's crown vic or grand marquis, so it'll keep the RPM's down on the highway and be more enjoyable to drive. So my question is, will this transmission bolt right on to my 302 engine?

Much appreciated, Nate B
Check out my thread:
http://www.mercurycougar.net/forums/showthread.php?50657-4R70W-AOD-Swap-Details
 

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AOD will work from a late '80s 5.0 Marquis/Vic or Mustang/Cougar/T-bird. Early '90s will be an AODE. Or you can use a 4R70W from a 351W (5.8L) truck or van through 97, or even a newer one from a 3.8 Mustang or 4.2 V-6 truck/van. Bear in mind that for your '68 Cougar, you'll really want a trans from a car with a floor shift for the correct linkage arms, or at least you'll need the linkage arms.

The AODE and 4R70W are essentially the same trans. The 4R70W has the added advantage of having a lower First gear, 2.84 vs 2.40, which gives a better off-the-line acceleration, yet they maintain a respectable .70 o/d ratio.

AODE and 4R70W are computer-controlled, so you'd need a stand-alone control unit conversion (~$400) to use one in your '68

That's why I stuck with a 'regular' non-computer-controlled AOD in my '89 Crown Vic, but swapped out the internals with the wide-ratio gearing from a 4R70W to make the hybrid known as a wide-ratio AOD (WR-AOD). My Vic's 3.55 rear gears feel like 4.19s off the line, yet are 3.55s in D and act like 2.48s in o/d. At 60mph, my engine is only turning around 1800rpm in o/d.

You'll probably want to do the same with your Cat's rear gears so the engine doesn't lug down too low in o/d. with 2.73s, the effective gear ratio is only 1.83 in o/d.
 

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Dang, AZCat beat me to replying again! That thread of his has all sorts of good info.
 

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If it comes from a column shift vehicle - be sure to rotate the shift selector 180 deg --- I got bit it the a$$ by that one....you won't be ablr to fix/change it in the car. I had to invent my own linkages to compensate for it! AZCAT has it down for you....not to bad to do and you will enjoy the ride.
 

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put an aod into mine in the spring due to the fact i put 3:80 ring and pinion into the rear end
bought the new crossmember ,lokar tv cable etc.. to do the swap
the only problem i had is my old headers hit the trans pan on both sides
caused a hell of a vibration
so, it was replace the entire exhaust or put the c-4 back in
c-4 is going back in.
 

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My hooker long tubes clear the trans pan - barely.....67/68 may be different bends? I wonder if you could just cut and re-angle the collector slightly? What about going shorties?
 

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Tri-Y's had same issue with AOD swap. Solution was to replace Tri-Y with JBA shorties. I admit I prefer the exhaust note of the tri-y over the shorties but I really do like having the overdrive.

my old headers hit the trans pan on both sides
caused a hell of a vibration
so, it was replace the entire exhaust or put the c-4 back in
c-4 is going back in.
 

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kind of have the same idea
my engine with long tubes and flowmasters just sounds bitc*en'
hate to loose that sound
and i don't really go that far with this car anyways

How much b.s. was involved with putting the shorties on ???
 

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Overdrive> longtubes!

I 'only' have Fox chassis Mustnag 351W-swap shorties on my 393W, then a 2-1/2" Fox-chassis Mustang off-road H-pipe. 2-1/2" pipes to 2-1/2" Mustang-fit DynoMax Super Turbos, then custom 2-1/4" tails. Sounds quite wicked for a Crown Vic! Since the Fox Mustang stuff was already made to fit around an AOD, I was good to go. The only 'problem' is the trans crossmember humps are not the same for Mustang/Vic, so it is a bit close (and had to cut off the Mustang rod-style exhaust hangers)... I ran back-to-back passes at the track both uncorked and through the complete exhaust - no difference in ET or top speed, so I can safely say that my full exhaust isn't holding me back! The shorty headers might be, but nobody and I man nobody makes longtubes for a Vic, let alone a 351W Vic!

To get back on topic, do the overdrive trans and find another solution for your exhaust. The o/d makes it much more pleasant to drive and your gas mileage will thank you! I was getting 15+ mpg out of my 393/WR-AOD/3.55 combo.
 

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Not too much BS. Cougar Bill did have to modify the tail pipes between mufflers and headers a little but the shorties allow you to clear the AOD and to use your factory P.S. bracket if you have P.S. which is a bonus.

 

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Question for people running AOD transmissions. Are any of you running flat tappet cams? If you are you could be in for a surprise. Back when AOD's were first used many cams failed do to lack of RPM's at cruising speed. Flat tappet cams need around 2500 RPMs at cruising speed to live a long life. You might get away with 2000 RPM's at a cuise but no less. The main reason Ford and other manufactures installed roller cams in the mid to late 80's was do to cam failures not to increase economy or performance. An extreme example is my 91 Crown VIC. At 60 MPH its turning about 1400 RPM's. This is do to tall gears and an AOD. BTW I get over 25 MPG on the highway driving an aero brick that weighs close to 2 tons at 70 MPH with the air on.

Bill
 

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As a fellow Crown Vic driver, I can surely vouch for the econo-gearing these cars had from the factory. Most common were 2.73 rear gears. With a stock tire diameter of around 27.4", that calculates out to only around 730 tire rotations per mile. That would only be ~2000rpm at 60mph for the engine in Drive, and with the .67 overdrive ratio that takes it all the way down to 1335rpm in O/D. With optional 3.08 rear gears, that goes up to 1500rpm, 3.27s (trailer tow I pkg) to 1600rpm, and 3.55s (HD Trailer Tow Pkg) to 1740rpm.

With the smaller 26" diameter stock size tires that came on our Cougars, that means that there are approximately 770 tire revolutions per mile. With a non-overdrive trans and OD trans, the engine RPMs at highways speeds are as fallows with the various RAR (Rear Axle Ratio):

RAR ------non-OD ----- w/OD
2.75 -------1630 ------ 1090
3.00 -------2310 ------ 1550
3.25 -------2500 ------ 1675
3.50 -------2700 ------ 1800
3.70 -------2850 ------ 1900
3.89 -------3000 ------ 2000
4.11 -------3165 ------ 2120

So as you can see, a car with an AOD with even 4.11 rear gears will be cruising at less engine RPM on the highway than a stock (non-OD) trans with 3.00 gears. The lower rear-end gearing makes for spirited driving around town, yet you still have economy at cruise. Now are you wondering why you haven't done an AOD/AODE/4R70W trans swap yet?

@ Wonderwrench, I seriously doubt the 'cruising RPM longevity' factor since cars had low gearing even back in the 60s and 70s. Look at that chart above again. My 351C-2V Cats all had 2.75 rear gears. They'd cruise at waaay less than that 2500rpm number. Wife's 460-powered '77 Marquis had 2.40 rear gears. That made for a cruising RPM of only ~1680 at 60mph. Same goes for my '73 Electra... I think the roller cam/overdrive trans combo was more about reducing engine friction and stricter CAFE standards. When I swapped from a flat-tappet to a retrofit roller cam in my 393, I could feel the difference in engine friction (resistance to rotation) when turning the engine over with a breaker bar on the crank bolt. I wish I would have measured that with a torque wrench..
 

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As a fellow Crown Vic driver, I can surely vouch for the econo-gearing these cars had from the factory. Most common were 2.73 rear gears. With a stock tire diameter of around 27.4", that calculates out to only around 730 tire rotations per mile. That would only be ~2000rpm at 60mph for the engine in Drive, and with the .67 overdrive ratio that takes it all the way down to 1335rpm in O/D. With optional 3.08 rear gears, that goes up to 1500rpm, 3.27s (trailer tow I pkg) to 1600rpm, and 3.55s (HD Trailer Tow Pkg) to 1740rpm.

With the smaller 26" diameter stock size tires that came on our Cougars, that means that there are approximately 770 tire revolutions per mile. With a non-overdrive trans and OD trans, the engine RPMs at highways speeds are as fallows with the various RAR (Rear Axle Ratio):

RAR ------non-OD ----- w/OD
2.75 -------1630 ------ 1090
3.00 -------2310 ------ 1550
3.25 -------2500 ------ 1675
3.50 -------2700 ------ 1800
3.70 -------2850 ------ 1900
3.89 -------3000 ------ 2000
4.11 -------3165 ------ 2120

So as you can see, a car with an AOD with even 4.11 rear gears will be cruising at less engine RPM on the highway than a stock (non-OD) trans with 3.00 gears. The lower rear-end gearing makes for spirited driving around town, yet you still have economy at cruise. Now are you wondering why you haven't done an AOD/AODE/4R70W trans swap yet?

@ Wonderwrench, I seriously doubt the 'cruising RPM longevity' factor since cars had low gearing even back in the 60s and 70s. Look at that chart above again. My 351C-2V Cats all had 2.75 rear gears. They'd cruise at waaay less than that 2500rpm number. Wife's 460-powered '77 Marquis had 2.40 rear gears. That made for a cruising RPM of only ~1680 at 60mph. Same goes for my '73 Electra... I think the roller cam/overdrive trans combo was more about reducing engine friction and stricter CAFE standards. When I swapped from a flat-tappet to a retrofit roller cam in my 393, I could feel the difference in engine friction (resistance to rotation) when turning the engine over with a breaker bar on the crank bolt. I wish I would have measured that with a torque wrench..
Well I spent about an hour writing an in depth reply only to blow it away by accident. #$*%&#! The short version, highway gears in 60's and eary 70's cars were not a problem as speed limits were 70 MPH plus so cruise RPM was high enough. The problems started in the early 80's when the manufactures figured out how to pass emissions by using computer controlled engine management systems. This improved engine performance especially low end torque. This allowed the use of AOD's, lockup converters and tall rear end gears. Over the next several years flat tappet cam failures became a big problem. The fix was to spend the extra money and use roller cams. A side benefit was roller cams are more efficient have wider power bands etc.

The main reason for my post was to explain that increasing the final drive ratio by installing an AOD may lead to flat tappet cam failures. Will it? If history is any clue I'd say yes. If I was going to install an AOD to improve MPG on the highway at a minimum I would change rear gearing to something like 3.90's maybe 4.10's even. In a perfect world I'd also use a roller cam to eliminate possible cam failure all together.

Another thing to keep in mind is higher final drive ratio's will only increase MPG if the engine has enough torque at cruising speed to keep the throttle angle low. A gasoline ICE engine is a self driven air pump with a CFM limiter, aka throttle plate. Using a taller final drive ratio to turn less RPM at cruising speed will only improve MPG if the throttle angle is small enough to lower the CFM of air going into the engine.

Finding the perfect final drive ratio for a given application would take much trial and error or some smart software and leased time on a super computer. This also means a big cam and tall final drive ratio will get less MPG than deeper gears that keep the engine closer to its power band. Using a roller cam widens the power band substantially which is just another good reason to go roller if you want an AOD. If you install an AOD without some serious research expect little or no gain in MPG or a big hit more than likely.

I would guess the easy way around this problem would be to use an RV grind roller cam and sacrifice some top end. This way you would have the best chance at getting the highway MPG up without spending a huge amount of time and money figuring out the best combination.

So much for the short version

Bill
 
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