Would a aod transmission out of a 88 F250 4x4 be good to use on my 72 cougar with a 351cleveland?
Not sure if there is a difference with tail housing lengths between car and truck AOD’s.
I am probably going to go with this route:
Monster AOD: https://www.monstertransmission.com/Custom-Built-Monster-AOD-Heavy-Duty-Performance-Transmission-2WD_p_5067.html#.XdG_nx_Qipo
With the conversion kit from WCCC
https://secure.cougarpartscatalog.com/store/p/15237-Transmission-A-O-D-Conversion-Kit-Repro-1967-1970-Mercury-Cougar-/-1967-1970-Ford-Mustang.html
Reason being is because I am probably going with this top end kit and the Monster handles up to 450 HP so that gives me room to grow if I add more power later.
https://www.summitracing.com/parts/EDL-2027?utm_source=bm23&utm_medium=email&utm_term=%25%25$cart.item.name%25%25&utm_content=10/28/2019&utm_campaign=Cart+Recovery_Cart+Abandon+Message&_bta_tid=14201433725476414856976525606277323725837413846181406241671308872663444496239844116800666668966829224778
If you have a choice, I would not recommend the AOD at all. In stock form, they are sluggish, and ill-suited to performance use. One of the big problems they have is a mechanical lockup for the torque converter that gives 33% lockup shifting into 3rd gear, and 100% in 4th. At full throttle, the friction materials are all fighting each other to snap that shaft going into 3rd and 4th. Eventually, either the shaft fails, or you burn things up.
There are rebuild kits to eliminate the torque converter lockup, and put in better parts to help them shift crisply, but by the time you spend all the effort and money, you still end up with a transmission that’s sub-par compared to a 4R70W anyway.
The 4R70W is the AOD’s direct descendant, and has the benefit of a lot of tech advantages. Asynchronous shifts means you can pick any gear, at any time, and it doesn’t have to wait for other gears to be engaged or released. Same with the torque converter lockup. The old 2-piece input shaft with its weak mechanical lockup is gone. Because shifting is handled electronically, the controller can engage gears gently, firmly, or bang into gear like a dragster, by simply changing the settings any way you like it. You can even have different behaviors programmed in, and switch between ‘modes’. For example, you might want a gentle ‘cruise’ setting, and a ‘sport’ setting, selectable with the flick of a switch. Even without modification, the 4R70W can handle around 600 horsepower without fuss.
And last but not least, it has a lower first and second gear than the AOD, which will let you get off the line quicker, which is nice for a street car that’s going to get highway use.
Either way, if you do the swap, make sure you upgrade your rear gears to something 3.50 or steeper to take advantage of the overdrive, and put in a non-steel (lightweight) driveshaft. If you spin a stock driveshaft with 3.73’s+, during high speed driving, the shaft will flex, causing driveline vibration and possible damage to the pinion, tailshaft, u-joints, or driveshaft itself. Harmonics being what they are, the only way to prevent this is to use a lightweight aluminum or composite shaft. With those, their natural harmonic frequency is much higher, so they can spin to far higher speeds without creating resonance problems.
Now that a mouth full!
Very informative! How much is this 4R70W?
How do you make the 4R70W (electronic shift) work with my 72 cougar with a linkage for shifting?
With a computer controller of course!
So, I must know, how did you finally make out with your engine troubles?! It was quite the saga…
Regards,
Robert
Hey Robert
Ended up pitching the so called CJ and going threw my original motor. Everything I did was right when it can to installing the pistons and rings, cam lifters. It looks like the intake gasket was allowing oil to blow by. Hence the smoke and crapy vacuum.
So how that work with a computer controller? And is it a lot of work and even worth putting the OD in?
You could find a 4R70W behind a V6 Mustang pretty easy. Best years for our cars would be 98-2001 because they still have the mechanical speedo gear, and all the best upgrades for reliability and strength, like the mechanical diode in place of the old sprag clutch.
The controllers are not ‘super cheap’. Get one from Baumann Engineering, and save yourself fuss and hassle. They’re the best, and offer them in a few price ranges.
However, given that you can literally take a junkyard 100k mile transmission and it’ll have virtually no wear for about $200 or so, add the price of the controller, and you’re still way cheaper, stronger, and much better than any upgraded AOD would be that can handle the same power.
I found one from a 1996 4R70W with 84,000 km for $350
What I ask him for (torque converter, wire harness)? And what else would I need to adapt it to my motor and rear diff?
The '96 would be ‘okay’. For $350, I’d hold out to find a '98-2001. Definitely get it with the torque converter. You’d have to have a flexplate with 164 teeth, balanced to match your engine (either 28oz or 50 oz). When it comes to transmissions, your bellhousing determines the number of teeth on the flexplate, and the starter. Your engine determines the weight of the balance.
With any overdrive transmission, you will want to upgrade your rear gears to something like 3.73 or so. You’ll also need to have a different transmission crossmember, lightweight driveshaft (you might be able to use an aluminum Explorer shaft), and your exhaust might require some work, because they’re wider than the C4. If you have an FMX, it’s about the same width.
Wow! Change one thing and then your pretty much changing everything.
Why does it matter with the number of teeth on the flex plate? And how do I get the right gear for my starter to match the flex plate?
What year explorer should I be looking for?
'98-2001. You can also find these in the Mercury cousin of the Explorer - the Mountaineer.
But keep in mind, the driveshaft may or may not be the right length. The tailshafts of transmissions vary from year to year and model to model, and even the rear end you have in your Cougar will affect the length that you need, so count on a little bit of modification no matter what. If possible, try to get the driveshaft from whatever vehicle the transmission comes out of, or at least the front yoke, to make things simple.
The size of the bellhousing and the starter placement is different for each model of automatic transmission. Most C4’s use a 157 tooth flexplate, and it’s not quite as big in diameter. Some of them later did use a 164 tooth flexplate, as do the AOD and 4R70W transmissions. If you tried to use the stock C4 flexplate you probably have with an AOD, the starter would be mounted in a place that would never even touch the ring gear.
But because Windsors use different external weights to balance the engine, the flexplate and harmonic damper both need to match the crankshaft for that particular engine. Most flexplates for the AOD and 4R70W will be set up for a 5.0, with a 50 oz imbalance, but they are very common with the 28 oz because they were also used with 351s, and that’s the correct weight for a 289 or 302 as well.
Definitely don’t get a ‘mod motor’ 4R70W because the bolt pattern for the bellhousing is very different from the Windsor six-bolt pattern.
So, simply said, once you settle on the right transmission for you, make sure you get a flexplate and starter that is made for that year of transmission, but make sure it’s got the right balance for your particular engine.
I think my head hurts!
Thanks for the lesson on transmissions and flex plates. You ok if I PM you for more information if I need it?
Don’t forget about block plate from the donor car and TV cable if use AOD.
'98-2001. You can also find these in the Mercury cousin of the Explorer - the Mountaineer. Question, I guess you would want the D/S from a non 4wheel Dr.Vehicle !!
The AOD is a much simpler way to go IMO.
AOD and 4R70W work out to be basically the same thing, externally. About the same size and weight. Disregarding how well they perform and handle power, the only real difference is that the AOD has a TV cable that requires a special linkage on your carburetor to operate. If adjusted improperly, your transmission will not only shift improperly, but it will burn itself up due to inadequate lubrication.
The 4R70 uses a throttle position sensor, and a controller box that plugs into the transmission to tell it how to behave, without the cable and its attendant linkages.
So in the end, they’re both about the same level of fuss to make work. Given the better durability, shift quality, better gears, and lower overall cost of the 4R70W (unless you want to use a stock AOD with all its attendant problems), for me it’s a clear choice.
Hey Smilodon, back to the driveshaft, this would come from a 2 wheel rear dr. Right?
I’ll keep an eye out for the 98-2001 4R70W and if some knows of one pm me. Thanks