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LTDII AOD conversion?

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72 RS 351 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 72 RS 351 Quote  Post ReplyReply Direct Link To This Post Posted: 25-August-2020 at 3:43AM
Originally posted by fordpower fordpower wrote:


how do you identify the yr on an AOD


You should want an 87 or newer, and the application is very important. You should avoid older units, a police CV(the shift pattern(2nd, no 1st)), and the plain model versions(low power commuter cars).

They all need help, but some are much better to begin with(the 302 HO cars etc).
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W
73 Ranchero GT 351C-4V &4R70W for sale later.
92 Lincoln Mark VII SE GTC, OBDII 347/4R70W
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Steve M. Quote  Post ReplyReply Direct Link To This Post Posted: 25-August-2020 at 7:43AM
The Fox body guys swear by their AODs. I  noticed that there're not very gentle on them either. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 72 RS 351 Quote  Post ReplyReply Direct Link To This Post Posted: 25-August-2020 at 8:28AM
The Mark VII's were about the best to begin with, most Lincoln owners would never manually shift their cars. All of those HO version AOD's are virtually identical, the 1987ish range is where the last output shaft improvement was made.

All AOD's need the "A" OD servo, and the AODE/4R70W intermediate pressure plate(it's thinner and allows four clutches instead of three. The early AOD's had only two of those clutches, and most low powered versions had "C" OD servos. Throw away those low end parts, those are what burned up very fast in early 80's AOD's. The police destroyed tons by the OD band burning up, someone must have been able to force WOT and 4th gear, which is stupid for an OD band. I read ages ago of how to do that in the VB, but I'd never consider it.

The guts of the AOD are all the same internal hard parts by name, as any AODE or 4R70W. The hard parts are not inherently weak links, but in above average/stock power, those parts are very important for reliability etc. So upgrading those parts is simple for anyone who builds Ford trannies, given the knowledge and finding the later trans to donate parts from.

Grab any 98+ 302 Explorer trans(4R), and you have almost all of the best parts to stick in an AOD(the rotating guts). They don't all swap over, but what does are all better than what's in all AOD's. The AOD still has to rely on the weird input shaft arrangement, and the rest of the control system(VB and servo's etc). Install the right shift kit, VB parts and upgrades, and it can be very strong. Aftermarket companies do VB's in many ways, full manual stuff mostly, and some automatic versions that just work better than stock.

I liked the TransGo HD VB kit the bet of the many I did in the 90's, it made almost everything way better, especially the driveability. The trans would downshift far sooner than any other VB kit, at throttle amounts below WOT. Getting onto a highway on ramp at a low or medium speed, the trans effortlessly went down a gear or two as needed. Basically it very quickly went to the lowest gear possible that you would want if performance was the goal(think road course instead of fuel mileage).

That's the AOD I rebuilt last, with the AODE wide OD band parts in it and Kolene steels, thin frictions in the direct. Years later we find out thinner frictions and steels is generally a bad idea. So I will be R&Ring that AOD to change the guts some. I need the sun gear shell from it to build my Lincoln's 4R70W(again I want the close ratios(requires that rare AODE sun gear shell(obsolete))). I had that before rebuilding it, shifting at 5400-5600rpm, 2nd/3rd was again lower(maybe 5000).

That difference between the first two gear shifts is very hard to fix(even out). I've read this past Spring of how the 2nd/3rd shift can be raised, that would be a huge improvement assuming it works.

The AOD needs a bunch of special building processes done to increase reliability above mild power, few place know of them or have done it. I've read of all of that, but most didn't exist before 2000 when I built that last AOD. So if you want an AOD, research carefully about the myriad of possible upgrades available, from parts to building steps. None of that is basically available at any local shop, but every shop could do it all if they knew what to do.
Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W
73 Ranchero GT 351C-4V &4R70W for sale later.
92 Lincoln Mark VII SE GTC, OBDII 347/4R70W
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Rockatansky Quote  Post ReplyReply Direct Link To This Post Posted: 25-August-2020 at 11:25AM
Don do you have a preference for Blue Plate kevlar or Alto Red frictions?

or is there something else that's come out since then?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 72 RS 351 Quote  Post ReplyReply Direct Link To This Post Posted: 25-August-2020 at 12:15PM
I recall those being about the best to use 20 years ago. I have blue clutches for all frictions of the AOD I mentioned, and Kolene steels(the black coating) in it too. From what I've heard in the last ten years, the OEM kind of Borg Warner frictions are as good as anything else. Smooth frictions are to be avoided, they make it hard for ATF to displace, so some slipping is assumed with those kind. I think the Kolene steels are still good, but not really any advantage as thought before.

What gains the most in power capacity is increasing clutch pairs without going to thinner frictions or steels. Sonnax now makes two new drums, in two versions of each. The best of the pairs adds one clutch set, for the direct drum and for the forward drum. That special direct drum is for 4R's and AODE only, I don't think it can be used in an AOD. The forward drum is under $200 and worth it for big power.

The direct drum is a kit that comes with a special sun gear, and is made with the stub shaft built onto it(which in an AOD is where the small input shaft engages the direct drum). So an AOD with that couldn't use the lock up shaft at all, only the one piece aftermarket shaft might be possible to use it in the AOD. That direct drum kit is about $600 or just under.

So add a clutch pair to the intermediate(2nd gear), one to the forward drum, the 98+ reverse drum, the wider OD band parts, and the several rebuild tricks for an AOD, and they can easily handle 500+hp. The high end builders know all of this stuff, they undoubtedly collect spare used AODE/4R70W's for the guts to put into AOD's.

Anyone can buy those in the same way, and find a builder to put it all together. The hard part is finding the tricks to do i the build process, and have your builder do all of that. The 4R70W doesn't need much at all beyond the stock rebuilding process.

That's how I can build my own 4R's that I have planned near future, they don't need much besides good rebuild parts. I own those special Sonnax drums, I have bought them to build two 4R's soon. The first will be for my Lincoln, using the AODE gear set(gives me the same close ratios as the AOD). I do plan to take some pictures to post on the Mark VII forum, though they have nobody really in need of such a transmission. Nobody hot rods a Lincoln really, not many anyway. It's a fun hobby.

Here are the two high capacity drums from Sonnax, the forward drum drops into any AOD/AODE/4R70. But the direct drum I don't think can go into an AOD, but it's cool to look at.

Don
73 Ranchero "Sport 72 front end", floor shift/console, planning EFI 7000+ rpm 351-4V &4R70W
73 Ranchero GT 351C-4V &4R70W for sale later.
92 Lincoln Mark VII SE GTC, OBDII 347/4R70W
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Big Bird Quote  Post ReplyReply Direct Link To This Post Posted: 26-August-2020 at 11:27AM
AOD has the mechanical lockup in 3rd and OD with the stupid hollow split input shaft in the trans.
Those break with abuse, (especially in heavier cars or trucks). AOD also has the hated TV rod or cable to be an added pain in the setup. AODE, 4R70, and 4R75 are progressively stronger derivatives/descendants with electronic lockup and computer control. In a perfect world, the 4R75 would be the choice.
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