Rebuild an AOD??...what should Poorman do??

[Mustmatt]

Project Poorman is underway and I need to address the transmission dilemma. Should I go for a complete AOD swap & rebuild the AOD myself or rebuild the C4?? I'm on the fence with this (or maybe looking for some encouragement with the AOD swap.)

A C4 will cost me $350 to have someone rebuild it...it's a good enough deal for me to pay this expense and do the uninstall/install myself.

Or

I've been reading up on the AOD swap. It sounds like the AOD isn't too difficult to rebuild for a better-than-average DIY guy like myself. I don't have any fabrication tools, so I'll have to buy the conversion parts for it. A little concerned about the exhaust because I have Hooker headers. I also understand that I'll have to buy and install 3:55 gears for drive-ability as well.

All this on a budget!! Any DIY guys do this on a budget? How did it turn out?



I'm doing a lightly mod'd car (see below)...

[Blues Power]

id go AOD and dont worry abuot the 3:55 for now until you drive it a while.
it may be good as is that is unless your rear is shot and needs some attention
then i take of it at the same time.

[jahearne]

I got lucky and came up with enough dough to buy a Silverfox AOD... good fortune. Awesome tranny!

I never rebuilt an AOD but PATC AOD, AOD Performance Transmissions from PATC, AOD Transmission, AOD Mustang, AOD site will give you an idea of parts/costs and tools. I've purchased conversion parts, flexplates, etc. from them. I've put overdrive transmissions in two cars and about to do a third. Highly recommend AOD over C4. AOD is a large tranny and heavy compared to C4 however.

[bartl]

My $0.02....

If the majority of your driving is at speeds above 55mph, like turnpikes and interstates, you may find the AOD gives you better mileage and less wear and tear on the engine at the expense of additional weight and more parasitic power loss.

If most of your driving is at speeds of 55mph and below, like country roads, etc., then the C4 will give you a more "comfortable" driving experience without the constant shifting in and out of OD and converter lock-up/unlock. I think the gear ratios also keep the engine in the right part of the power-band more of the time.

If you were to go AOD I would opt for a gear ratio between 3.23 and 3.55, depending on how much grunt you want from low gear.

If you go with the C4 I would opt for a 3.00:1 ratio.

JMHO.

[LindenBruce]

The AOD is a pretty straight forward rebuild. You can use readily available seal tools for most of the pistons yourself, just go nice and easy and take your time. I only need the special AOD seal tools for one piston, so to save me some money I took that assembly down to a local transmission shop and they popped the assembly together for me for free! If you go and buy a used transmission try and locate an 89 or newer with a short tail shaft like out of a Mustang. They have some upgraded internals and oil system mods from the factory. You can also further upgrade the internals by using parts from an AODE/4R70W if you want, but that's not really necessary just an option.

You maybe be able to use your crossmember by drilling two new holes for the mount, so don't go buying that part until you know. I made my own since I had the welder on hand. If you have access to a welder and a band saw, you can make your own crossmember.

You also don't need to go hog crazy on conversion parts like shifter linkages for instance. You can use your existing shifter rod, but it will need to be modded to get it to work. It will save money, but add a little time to the conversion. And if it's your time it's a good learning experience. One thing you will need to really take a hard look at it the Throttle Valve cable arrangement. You will need an adapter at the throttle but those are available for not much dough. You can use the factory TV system or go Lokar, which I hate myself. If you go factory I have pics of my system I can forward to you if you like that will show you how to mod the factory EFI/AOD brackets and use the Ford TV cable.

The AOD is wider in the waist and your headers may not work with it. But that can be resolved by using a different header or going with a set of shorties. I bought my rebuild parts from Silver Fox Performance Transmissions. You can also go to clickclickracing.com for a ton more info on the AOD. Bad Shoe Productions has a video on rebuilding the AOD and it's a great tool. Bruce

[Mustmatt]

Thanks guys for the advice and links. I'm still raising cash for the transmission and other parts, so I have a little bit of time to do the research and figure out an affordable path.

I really don't need an AOD since I work about 2 miles from home and I'll rarely use the over-drive. However, since I need to go through the transmission anyway, I may as well do the swap anyway.

I have a Mig 135 welder which I've only used for for sheet-metal. Would it be sufficient for thick metal like a crossmember?

Thanks!!

[LindenBruce]

Yeah your welder will do 3/16" thick material on a single pass so yeah you can build a crossmember. If you use 1/4" metal all you need to do is run an extra bead if you feel you have to. But even then I don't think you really need to worry about it. I have pics of my crossmember too if you decide to go that route.

With such a short commute you might consider keeping the C4 for now and do the AOD in a few years, if you are like the rest of us with cash being in short supply. The C4 is cheap to rebuild and can be made to handle power and torque. B

[Rebel Racing]

Originally Posted by bartl

If you were to go AOD I would opt for a gear ratio between 3.23 and 3.55, depending on how much grunt you want from low gear.

JMHO.

Just my .02............our car came (from the PO with a 3.50 rear). In our collection of resto parts I got a 3.80 R/P at Summitt. since I already had them, we installed them. I like them with the AOD. Just saying that if you will be looking for gears, I'd personally go right to a 3.80 for an AOD. Just my .02

[DesertCoupe5.O]

Originally Posted by Rebel Racing

Just my .02............our car came (from the PO with a 3.50 rear). In our collection of resto parts I got a 3.80 R/P at Summitt. since I already had them, we installed them. I like them with the AOD. Just saying that if you will be looking for gears, I'd personally go right to a 3.80 for an AOD. Just my .02

X2, I have 3.73's in mine and they're perfect. The AOD swap is straightforward, but there is quite a bit involved. If you're not going to use the OD i'd stick with the C4 and avoid doing the 1-2-1 shuffle.

[Kenster]

Originally Posted by bartl

If you go with the C4 I would opt for a 3.00:1 ratio.

JMHO.

Bartl, does the engine make any difference in that? Does a 289 with a C4 need a different rear end than a 200?

I have a 2.83 rear end on my 68 vert with a 200-six. That's the way it came from the factory according to Marti. My understanding is that the 2.83 was a good compromise. Not real strong on the low end but good for cruise/gas mileage. Does that sound about right?

I can't see ever changing my C4 or rear end but just like to learn more about my car.

Thanks!

Ken

[GypsyR]

Yes, if you're after just a driver that won't "scream" on the highway a 2.83 is a fine choice for a 200. Sure you're giving up some oomph when the light turns green but if you're happily cruising a 200 I'm guessing that isn't a priority anyway.
From above, I used a similarly sized MIG to make a crossmember. It should be fine. Just remember to crank it up and go more slowly for solid weld penetration. I've been known to practice weld a couple of pieces together and then clamp them in a vise to see if I could break them apart.
I'm addicted to overdrive and like AOD's. With light throttle I can float SWMBO's into OD at 45 mph and happily cruise at 1500 rpm at 50 mph. Incidentally, AOD's son't have "lockup converters", that came with the later AODE/4R70W's. So there is no lock/unlocking going on with them. 3rd and 4th are mechanical lockup (which I like). One of my drivers has an AODE/4R70W with the lockup converter which I find barely noticeable. If it constantly shuttled in and out of lockup I'd be tearing it down to find out why.

[Roddster]

I had a self built/modified AOD in my 66 Coupe. Worked alright. Then I noticed my wife not driving it anyway, so I put in a T-5. Slightly more money, way more enjoyable to drive. More valuable too.

[wheelsup351]

what kind of power are you making? the AOD's that came in foxbody's don't hold much and the OD goes out on them often.