I would appreciate some feedback on your thoughts of replacing a C4 with an AOD. My truck will have a 351W that I pulled from a '79 LTD II complete with the C4. I drove this car into my shop to remove the running gear. I removed a perfectly good 9" rear and replaced it with an 8.8 (3.55 gear) out of an Explorer. My thoughts were to go with the AOD as I intend to Cruise in this truck and I'm looking for dependability and mpg more than neck snapping acceleration. I have heard that setting up an AOD is not an easy task and now I'm having second thoughts. Help please!! thanks for you input. Steve

 

The biggest issue is chaging over the throttle bracket to accept the TV cable, then adjust the TV cable is a snap. I've seen many aftermarket brakets for bolt in installations.

You'll most likely have to change/relocate your tranny mount crossmember and shorten the drive shaft.

The AOD I'm using in my swap, still uses a 3 position gear selecor...1 D and OD, so you should be okay with your current gear selector.

 

You sure it is a C4? Most trucks had the C6, which is not so great on mileage.

Assuming it is a C4, the most important thing is the final drive ratio - with the C4 it will be 1 to 1, but the AOD will be like 0.7 to 1. You can correct the difference between the final drive ratio by changing the gears in the rear end - high gear with the C4 and a rear end ratio of about 2.5 will be the same as the AOD in overdrive using the 3.55 ratio rear end.

The only functional difference is that the AOD has 4 forward gears and the C4 has only 3.

I would go with the AOD as it allows the use of a lower rear end ratio for street use and still gives a economical ratio for highway use. But if you want to use the C4 it need not cost you mileage.

 

Just do the linkage correctly and you will love the AOD. I first did the change in my '49 Merc,(car) 351W and went from FMX to AOD about 12+ years ago. Never looked back and that same trans is still in place and I have since changed to a 5.0 HO in front of it. I had to fabricate my linkage at that time, but I think Lokar has what you need now. I started out with a adjustable rod type linkage and now am using the cable that the '90 Mustang engine used. 3.55 is a great rear ratio with an OD.
However, don't even drive around the block until you have the TLV linkage in place and adjusted.

 

The LTD II could be had with three different transmissions...a C-4; an FMX Cruiso; or a C-6. The trans pan gaskets for these 3 trannies are all different...with the C-6 being the largest with a big cutout.

If you plan on using an AOD...please be aware that they are expensive to rebuild and don't function well when hot. Stay out of Overdrive in heavy traffic, and add a tranny cooler.

When the AOD was introduced in 1980...it had tons of warranty issues.

 

I have an AOD in my 53, would not even consider going back to C anything. The normal rebuild [carry out] price around here is $600. C4 cost $450. TV adjustment with a guage is mandatory. Even with my Lokar setup it required adjusting with a gauge to set pressure to function properly. I have a C4 in my 46 coupe and can't wait to switch to AOD. Have one ready on a cart, just waiting it's turn.

 

AOD is the way to go.....I had the original tranny in my 54 and it couldn't holdup to the 302's power band setup I have....if the right shop sets you up, you can still snap a couple of necks in the cab...I do it frequently when a little rice burner pulls up next to me....

 

Thanks to all for the replies. I'm relatively new to truck building but with retirement approaching in the next 5 years I'm starting to get serious about this hobby. The trans that came from the LTD II was definitely a C4. I forgot to mention that I bought that car new-special ordered even- and was thoroughly disappointed at the time that a 351C / 4 speed option wasn't offered. I have already puchased the AOD. It was pulled from an '82 LTD with a 302 that was a driver being parted out. I also got all the linkage but since I've already bought Lokar shifter,gas pedal, brake pedal, I like the sound of Lokar linkage. I have a trusted transmission shop that will do the set up for me. I just wanted to make sure I wasn't making a big mistake. This site is my mechanic's helper!! Thanks again guys. Steve

 

Howdy,

I have a next door neighbor that has an 85 F250HD 4x4 with a 351 and an AOD.

He swears by it.


I'm planning an E4OD in my F-600.


Regards,


Rick

 

When the trannies were new...I remember that there were hordes of people who swore at it.

The largest Limo company in SoCal converted all their 1980-1985 Town Cars from AOD to C-6's. Once a kit was figured out...the dealer I worked at offered to change over anyone's truck or car.

Maybe enough time has passed...maybe since I retired, Ford figured out how to make the AOD more reliable.

 

Yes and yes! Set up properly, the AOD is a very good tranny. As someone else said, a tranny cooler is a great idea/good insurance for the little added cost.

 

My son had a '85 TBird with a bad early (linkage type) AOD. Three trans shops told us that the parts that are supposed to be replaced during a rebuild cost $800, without labor. That was using factory-quality parts. I did some research into AOD's to see if there was a way around it. There was a definite series of improvements in AOD's so that by '90 they were "fixed". Earlier ones can be upgraded easily and cheaply to strong enough by replacing the OD servo with the HD model used on V8's. There were three servos, light, medium and HD -- hope Ford saved a ton of money with the smaller ones, they cost a lot of people confidence in their cars! The OD band/servo failure was the biggest problem.

 

I have had two rebuilt, neither one was over $600. One $525, one $600. Both are performing just fine. One was 84, other 86. Both rebuilt by a quality local independent shop. These are the same things people say about the early GM 700's. The one in my 84 GMC pickup only lasted 225,00, at least that was on it when I sold the truck.