AOD to flathead
 

I know this message board is not for “hot rods” or customs, this AOD is just about the only thing I’m upgrading on this car. Everything else will be pretty stock.

Anyway, my question is the kit from speedway motors came with a bunch of nuts, bolts and washers. I have four star washers. Do they go on the flex plate to crank shaft bolts or torqu converter to flexplate nuts?

And then which ever one they go on do the other ones require some sort of lock washer?

They only gave me four star washers so those go on one or the other. They gave me 6 split washers and 6 nuts which I’m fairly confident those go to the studs that attach to the trans.

I appreciate all you guys’ help!

Re: AOD to flathead
 

I don't have your answer for ya, but why wouldn't you call Speedway's Tech line to get this question answered authoritatively, rather than from a bunch of us opinionated old farts, some of which are likely to pull an uninformed-BS response right out of their butts? After spending all that money with Speedy Bill, I think the least they owe you is the correct install info! But what do I know? DD

Re: AOD to flathead
 

Thought about that. Tech line closes at 5 CST. But I think I figured out that the star washers fit the flexplate to crank Bolts. They are a little too big for the converter studs. I think I’m good now. Thanks.

Would you put lock washers on the converter to flexplate studs?

Re: AOD to flathead
 

Not trying to be a jerk, but this is an example (in MY case) of having to pull an answer out of my butt. That certainly doesn't mean that MY answer would be accurate. And I DON'T want to BS you, my friend. I just don't do flex plates! DD

Re: AOD to flathead
 

Don't apologize for wanting to put an automatic behind your flathead. The 3 speed in my '39 p/u came from an older gentleman who could no longer work the clutch in an absolutely gorgeous '39 convertible. His options were either give up driving a car he loved and had forever or install an automatic. Personally I'm glad he chose the automatic because I got a great trans but more importantly he got to continue to enjoy his old Ford. JMHO.

Re: AOD to flathead
 

A note here. I think this kit uses the late starter. If it does, the block must be ground to clear it. Simple job for a hand grinder, you don't have to take of much. The AOD is a good choice, however it does need allot of power to operate, car should have 3.78/4.11 rear.
Good luck
Gramps

Re: AOD to flathead
 

Ford used a bolt lock ring on the Ford-O-Matic flex plate. The lock ring had two tabs to bend up for each of the four flex plate to crank bolts to keep them from coming loose. Star washers (usually the internal type) are relative thin for close fits should work OK for the flex plate when the torque up it relatively tight.

Some torque converters use lock washers and some don't. It depends on the design of the nuts. A person can always use a lock nut if they want them to stay more secure.

If your kit came with a decent pressure gauge, you're all set to adjust the TV cable. It has to be right or the transmission can be damaged. A well built Ford AOD can take anything that a flathead can put out. C4s also work just fine but the rear axle needs a lower numerical ratio for them. The AOD would like a higher numerical ratio to pull better and still take advantage of the overdrive.

What vehicle is this going in?

Re: AOD to flathead
 

I put an AOD in my ‘53 8ba (Speedway Adapter) and used stars on Flex to Crank bolts. Used an Econoline 6 cyl flex plate and re-centered the holes. Used a modified late starter and ground the block. My rear gears are 3:90s. Was a problem with eratic and late shifting. Put in a Transgo shift kit (about $30 at Summit) and it cured the problems. I run about 2200 rpms @ 65 MPH.

Also used Lokar Linkage and suggest you have someone that knows AODs setup the throttle pressure. If incorrectly done, it can ruin the AOD. Only takes a few minutes and best done with a pressure gauge.

I am very happy with the AOD as I am gentle with my car. No complaints.

Attachment 431694
Attachment 431695

Re: AOD to flathead
 

As others have already stated you will need to grind a little bit off the block for the starter to fit. I pulled a starter off a Ford 400 small block automatic I already had and put on my 8ba with AOD and it engaged to far and blew apart. I got one for 1972 Ford 289/302 engine manual transmission it has the shorter gear and it works great.

Re: AOD to flathead
 

Thanks, guys. Much appreciated.


So this is going in a 50 Ford Coupe. Originally had the overdrive trans. I'll check the gear ratio and see what it is now. I already ground the block a little for the starter. I bought the kit with the starter from Speedway so I think I'm good there. It came with pretty thorough instructions which I thought good of them. They were thorough but didn't come with torque converter nuts, and didn't really specific where the washers went. The only shortcoming I could find. I ended up using grade 8 nuts with some Loctite. I don't think there would be much room on the stud for a split washer. Maybe a star washer.
Also, Riverside Transmission in Riverside, CA supplied the AOD. They're good guys, he told me to bring it back once it's running and they'll adjust the TV cable for me.


Rebuilt with a mild shift kit.

Re: AOD to flathead
 

Suggest you adjust the throttle pressure as best you can before driving or pay someone to come out and adjust. The company that rebuilt my AOD did that at no charge. However, I would have paid. Also good to check rear end ratio before driving. Putting the kit in before you put in the oil is a lot cleaner. I would guess your rear end ratio in the 3:70s. That is still to low for proper AOD shifting and downshifting. The valve body kit corrects this. As mentioned, I was very unhappy until I installed the kit.

Re: AOD to flathead
 

Let us know how it works, Quite a few people would like to know.

Re: AOD to flathead
 

I believe "shoeboxes" with O/D had 4.11's, while non-O/D cars had 3.55's. My '51 (which came without O/D) is 3.55. I think Fordamatics got 3.23's. I believe "chunks" from up to '55-'56 can be used, but I think the later ones need matching axles.

Re: AOD to flathead
 

The precursor to the 9-inch doesn't have many sources for ring & pinion gears.

Re: AOD to flathead
 

The use of a heavy axle at threar of the car, gives a harsh ride like a pickup. Something like a spicer 35 is light but will handle 300 plus hP, and gives a much better ride. and their cheaper. Most come with the 4 1/2 on five bolt pattern wjich is an improvement over the 51/2 on 5. It's much easier to find these rims in the junk yard and converting to the 16 wide profile tire will also give a better quallity ride. Pretty soon the 15" tire will go the way of the 14" Gota plan ahead to keep our old cars on the road.

Re: AOD to flathead
 

I have two 50’s and a ‘51 and there all 3.73 rears...... Mark

Re: AOD to flathead
 

I think I have heard about more 3.73's in non-OD shoeboxes than 3.55's. It's probably a regional thing; hills and mountains or flatlands. My car which, I absolutely know was original, was made in the St. Paul plant, and an optional rear end is not specified on either the order or the invoice.

Re: AOD to flathead
 

Be sure the TV is set as best you can before driving it to the shop to set it up. A bad TV adjustment can destroy an AOD in short order.

Re: AOD to flathead
 

Actually Ron, I don't think an AOD needs any more power to operate than any other automatic trans. Almost all automatics operate on the same basic principles and run pretty much the same line pressure, so power requirements are about the same. An AOD is 100% lock up in 4th gear and about 70% lockup in 3rd so little to no power is absorbed by the torque converter in 3rd and 4th. Thus, the AOD is actually more efficient and uses less power than 3rd gear in a C4, etc.

Re: AOD to flathead
 

I agree with others about setting up the pressure before even thinking about driving the car. It can be done up on jack stands or a lift but it has to have the correct pressure at idle to operate above idle. If the clutch plates slip, it doesn't take much slippage to burn them up. The AOD has no vacuum modulator. The TV cable is what controls the pressure when properly correlated with the throttle. All you have to do is adjust the cable until it has the correct pressure at idle. Most of the TV cable kits are easy to adjust. Most are universal type kits and come in different lengths. Your AOD kit should have come with one for the price.

At worst case, a person can always have a roll back wrecker take it over to the shop to adjust it. Torque converter nuts are easy to source. They all pretty much look like these.
https://www.monstertransmission.com/...E#.XtGCvyN_Pcs