Anyone using aod's in their bumpsides?
I am thinking about the ins and outs of a swap.
Happythanksgiving

 

Others will chime in.....

Meanwhile, read this for detailed nfo: Ford AOD Overdrive Transmission | Hemmings Motor News

 

Lots of people have installed the older AOD. This transmission was produced from 1980-1993. It's best to avoid the '80-'87 models. They had various factory internal flaws --one primary flaw being a lack of lubrication to the tail housing bushing. These flaws were addressed and corrected with the '88-'93 versions.

In stock form, the shifting characteristics of the AOD are lack luster. With a valve body kit, shifting is much better.

Initially, I was considering installing an AOD in my truck but, after I did a good amount of research comparing the AOD and the 4R70W, it was clear to me the 4R70W was a MUCH better transmission choice.

The 4R70W was the 3rd generation transmission that evolved from the old AOD. It was produced from 1993-2004. It's initially more expensive to install than the AOD, since the 4R70W will require a stand-alone shift controller (4R70W is electronically shifted through solenoids in the valve body) but, the 4R70W has way more capabilities that the old AODs can't come close to matching.

The best 4R70Ws to have are from the '98-'04 3.8L Mustangs, 4.2L Ford trucks or the 5.0L Explorers.

This is the '98 3.8L Mustang 4R70W transmission that will replace the C-4 in my '69 F-100. This was a U-PULL-IT item --$138.00 dollars.



This is after I pressure washed all the grime off of it.





I made a transmission holding fixture to attach to an engine stand so I can rebuild the transmission before I install it.

 

thanks for the info guys, needing something to do Thanksgiving morning ive been crawling under my 69 and made a startling discovery
it has what appears to be an AOD!
pn/is RF-E3SP-7006
the PO insdtalled what looks like a mustang floor shifter which is not my favorite as its short and hits the seat in low.

 

I wonder if it's easier and cheaper to just change the rear end ratio? For example, I have 3.0 gear in the rear end. I am slow as a snail off the lights but the truck comes alive on these Dallas Highways. I can tell it's not working hard at 65-70mph.

 

I put in an AOD, now I'm putting 4.11 gears in the back to compliment it.

To anyone considering an AOD swap, think hard. If you drive your truck fast for long distances, the AOD helps a lot. But you'll need at LEAST 3.50 or 3.73 gears depending on your tire size. The OD gear is very tall. There are ratio calculators online to find what you need. You want to be cruising at about 2,000rpm.

If your truck is only a weekend toy, or is a hot rod kind, a C4 performs much better and is cheaper. Just run a higher ratio rear gear. 3.25 3.00 or 2.72 are good. Depends on your driving style.

 

I say do it! It was probably the best upgrade I have done to my old truck, and then efi is second. I have the 4R70W bolted to my 460 and what an amazing transmission, I highly recommend it.

D

 

With any transmission other than one with overdrive, high gear will be 1:1. If you go to a high rear end gear ratio --3.00:1 for example, you'll get better fuel mileage but at the expense of losing your low end torque and rapid acceleration.

If you have a low rear gear ratio --3.70:1 and a non-overdrive transmission, you'll have low end torque and fast acceleration but at the expense of higher fuel consumption, higher engine RPMs at highway speeds, higher decibel level inside the cab and a greater reduction in your top end cruising speed ability.

An AOD has an overdrive ratio of .677 or, rounded off, .68:1. To figure final drive equivalent, multiply the rear end ratio by the overdrive ratio.

If you had a 3.70:1 rear end ratio and a .68:1 overdrive ratio, the final drive equivalent would be 2.52:1. In overdrive, it would be as if the rear end gears were a very high 2.52:1 ratio.

An overdrive would allow you to run lower rear end gears for low end torque, pulling and quicker acceleration but, at highway speeds in overdrive, the RPMs would be much lower, gas consumption would be lower and there would be a greater reduction of noise in the cab. --an overdrive gives you the best of both worlds.

An AOD doesn't have as good of lower end torque multiplication in 1st gear as a 4R70W. An AOD has a 2.40:1 1st gear ratio. A 4R70W has a 2.84:1 1st gear ratio.

If you were building a hot street truck, you need a torque multiplication factor of at least 9:1 to be a strong performer. To figure this, you multiply the transmissions 1st gear ratio by the rear end ratio.

An AOD and 3.70 rear end gears would give you a torque multiplication ratio of 8.88:1 [2.40 1st gear x 3.70 rear end gear = 8.88] (that comes out a little on the weak side and is short of the 9:1 threshold to be a strong performer).

The same rear end gears with a 4R70W will give much better results. 2.84 x 3.70 = 10.51:1 --much stronger torque multiplication ratio than the AOD.

 

^ thus why I am installing a set of 4.11 gears. 1st gear will be 9.86, while overdrive will be a mild 2.75. And with 31" tires, that's a sweet combination!

 

Ahh, but if you had a 4R70W with the 4.11s, the torque multiplication ratio would be 11.67:1.

Final drive equivalent would be 2.88

 

I would also need an electronic trans controller, something I don't want on my all mechanical truck.

 

You could take the internals of the 4R70W and install it in an AOD case and have a non electric OD.

D

 

Maybe I'll do that when I blow up this AOD. Haha.

 

If anyone needs any help from advice to whatever on a swap like that just let me know. I have done many swap setups where they wanted to either swap the 4R70W gearset into an AOD or the AOD gearset into a 4R70W. I have also worked with both the PCS and Baumann controllers.

D