Ford automatic

So I'm getting to choose the transmission for my model a roadster build.I am running a 302. I already have an aod out of a 88 van.I don't know much about tranys but was wondering If a c4 or c6 would be better. Any thoughts are appreciated. Thanks Brian

 

I put an AOD in my Fairlane last year. It has a lower 1st gear than the C-4 so it scoots pretty good and it gets about 17 mpg now with 4:11 gears and a stock engine. Just hard to get used to the way it just sort of "dumps" into overdrive though.

 

If the aod is good I would use it- especially if its gonna be driven a lot-- but you need to run a rear gear of at least 3:50 or more. IMHO

 

Yeah, I would stay away from the C-6. It's overkill for a 302. Saps too much horsepower to run it. For my money I would stay with the AOD.

 

The upside to the C-4, it should be cheaper to rebuild if necessary down the road than the AOD. That said, you will have more fun with the overdrive and a favorable rear gear. Fun and decent fuel mileage are a good thing.

 

I have two cars that used to have C4 transmissions, but now have AODs. I can't imagine any reason I would want to go back to the three speed on a street car. The balance of better acceleration in town (my rear gears are 4.57 in one car, 3.90 in the other) and easy cruising on the highway can't be beat.

 

Thanks for the info.I appreciate it

 

In the MPG Dept. the extra gear only helps out on the highway. In town you'll get just as bad a mileage with 3.50 & up gears with the AOD as a C4. The early 80s Crown Vic Police Interceptors had 3.08s (351W & AOD)and were fast enough even with the weight of a Crown Vic for Cop work. The shift pattern of Van AODs is reversed from car AODs,take that into account when setting up your shifter.

 

Your differential ratio should dictate your choice of transmission, unless you plan on swapping the rear anyway.

 

One thing about the AOD is throttle valve cable adjustment. The trans uses throttle position to control clutch pressure. If the cable is out of adjustment the clutches may slip and burn up, especially the OD band.

I have a 5.0 HO with AOD in my daily driver. With the cable adjusted to spec, it upshifted early, and was slow to downshift. I hated it. I tightened the cable up a little so the trans thought more throttle was being applied. Now it shifts later, and firmer, with quick downshifts and is a lot nicer to drive.

By the way, it's a 3800 lb car with 3.27 gears, 27" tires and scoots along just fine. In a light A roadster, I think you could run highway gears, or taller tires no problem.

 

The 1988-93 AOD is prefered as it has the improved valve body and lubrication upgrades and is still non-computer,if you have a pre-1980 302 it has a 28 oz balance factor the AOD cars 1981 and later are 50 oz so a matching flexplate will be needed.For a real education on the AOD go here: www.clickclickracing.com

 

The C4 & C6 have 2.46/1.46/1.00 gear sets. The AOD has 2.40/1.47/1.00/0.67. The AOD-E/W, later changed names to 4R70W got a 2.84/1.55/1.00/0.70 gear set but is also computer controlled.

The gear set from the 4R70W can be swapped into the AOD. The AOD is a good transmission with a bad rap. It must have a TV cable and that cable MUST be set properly. Once you do that it'll give you few problems. There are things you can do to it to make it perform well and last a good long time.

One of the best sources for info on the AOD is www.becontrols.com

 

So my 92 AOD has the same first gear as my old C-4? Thats good to know.

 

The TCI constant pressure valve body is supposed to take the gnat's ass adjustment out of the kick down, though it must still be used.

 

I think this is a worthless product. All you have to do is install and adjust the AOD correctly. There are several websites that tell you how to do it. Why spend money to get something you don't need if you take the time to do it right to begin with?

 

That's the rub, isn't it? Seems like a lot of reports of people toasting their new AODs.

 

I'd go with the AOD. Setting the TV pressure is really pretty simple

 

I've got a C4 in the 40. If I had it to do over it would be an AOD.

 

True 'dat Jeff.

I've got one of Dan's (Silver Fox Performance Transmission) constant pressure valve bodies along wit' a Trans-Go governor n' a 2300 stall (and a whole buncha' other shit) in my E3 PKA tagged AOD.

Dan builds each one of his valve bodies to your individual specs- I can't speak for the TCI valve body but with Dan's constant pressure model, the throttle valve cable is just a cable to adjust shift points and nothing more- shifts are positive and progressively firmer with throttle position.
At WOT, my shifts are in 4000rpm range.

Would I put another AOD in another car? Hell, yeah!

 

Thanks to one of our 52-59 Ford Social Group members this is available:http://www.youtube.com/watch?v=jZwsQViZilQ However the gauge set shown is now $26.99