3.8 aod conversion

Topic: 3.8 aod conversion (Read 2021 times) previous topic - next topic

3.8 aod conversion

July 25, 2008, 04:04:39 AM

is it beneficial to put an aod in a 3.8 84 cougar? would you see better gas mileage or power? also, would the aod require a different length drive shaft?

3.8 aod conversion

Reply #1 – July 25, 2008, 10:01:15 AM

You may get a bit better mileage on the highway, no difference in power(unless you upped the torque converter, may not be a bad idea)... D/S length should be the same, if not easy enough to find one from a 5.0 AOD...

If you're paying someone for the job, prob isn't worth it...

3.8 aod conversion

Reply #2 – July 25, 2008, 02:14:18 PM

Just FYI, the AOD was an option on 1986 3.8 V6 engines. And of course, that was the standard trans on all 1987-88 Cougars and non-turbo Thunderbirds. That being said, there should be no significant differences between the V6 versions of the AOD. You could probably even use a V8 version.

I'm with Tom on the power thing. Using a V8 converter should get you about 100-200 rpms higher stall speed. Otherwise your fuel economy might go up a bit. Really the benefits are negligible on paper...but in the real world it just might add a lot of pep to the motor. Never know until you try. The biggest issue that I see: getting all the rods and brackets and shift linkage. If you have a donor car, no problemo...otherwise you might be in for an ordeal.

is there something wrong with the current C5 trans or something? Because those are based upon a C4, meaning they can be built up pretty nicely.

3.8 aod conversion

Reply #3 – July 25, 2008, 03:27:40 PM

wouldnt he have to run new wiring or snag the harness and such from an original AOD equipped car, and swap the ecu from said car?
somethings telling me this isnt a plug and play thing.

im with him, whats wrong with the c5?

3.8 aod conversion

Reply #4 – July 25, 2008, 05:22:30 PM

Quote from: Ductape91;229016

wouldnt he have to run new wiring or snag the harness and such from an original AOD equipped car, and swap the ecu from said car?
somethings telling me this isnt a plug and play thing.

im with him, whats wrong with the c5?

The ECU or AOD could care less about one another... I run a 3.8 SC AOD in my TC with a A9L 5 speed Stang EEC...

May not be a bad idea to swap to a later ECU just because the programing is better...

For converter, I'd go with a 2400 rpm stall lockup... You'd feel froggy around town and still have the full benefit of OD at cursing speeds... Any 5.0/3.8 AOD will work(even one from a early '92 4.6 Cn Vic or G Marq) Hangups are are differences in manual linkage on trannys from floor shift cars, plus the LSC and P/U trannys are a inch longer...

BTW be sure you have the correct bracket for the TV cable, or you'll probably fry it in short order...

3.8 aod conversion

Reply #5 – July 25, 2008, 09:08:42 PM

about the linkage, just go to a floor shifter, Youll like it trust me it after over a month of me screwing up it was worth it

3.8 aod conversion

Reply #6 – July 25, 2008, 09:49:08 PM

wow, wasn't expecting that many questions... guess i shouldn't have been so short and non-descriptive with mine...... i'm buying an 84 v6 this weekend with a column shift..... the aod in the 83 i have is getting a little too weak for my ho so i wanted to replace it.... what i was wondering, since i'll probably get the aod for the 83 from bearmax, i'll still have my origional aod sitting around..... the v6's transmission is supposed to be ok, but if replacing it with the aod would help make it a better dailyish driver, i want to do it......

as for everything else, the ecu has nothing to do with the transmission in a fox car right? since our transmissions aren't electricly controlled, i didn't think the ecu cared what trans you have... but then again, i could be wrong (and usually am :))

3.8 aod conversion

Reply #7 – July 26, 2008, 02:20:07 AM

You are quite correct. The AOD is not electrically controlled, and the ECU could care less what tranny is behind it, with the possible exception of one that's set up for manual transmissions. It handles the idle speedup slightly differently on a manual, but dunno if it would be noticeable. I've been thinking about exactly the same thing. I know that the C5 keeps the little 3.8 wound up like a watch spring out on the highway. If I can drop 1500 RPM at 70 mph, the fuel savings has to be significant.

3.8 aod conversion

Reply #8 – July 26, 2008, 05:49:34 PM

ok... so i just bought it :) now i have 2 cats (at least i can let the wife claim hers back)... sooo, pics and story will be posted tomorrow night when i get home :)

p.s. we have irish twins :burnout:

3.8 aod conversion

Reply #9 – July 26, 2008, 05:54:13 PM

If the C5 is in good condition, no way I'd swap to a iffy AOD(you stated it wasn't as good as once was)...

3.8 aod conversion

Reply #10 – July 26, 2008, 05:58:16 PM

well, i drove it to my parents house (about 20 miles) with no shifting issue at all.... it has a wiring issue somewhere that drains the battery overnight.... at first glance, i think it's the solenoid and positive battery cable (it tried to start itself without the key when first jumped) anyway, other than the suspension being trashed (dude i bought it from was a BIG boy), it seems pretty solid...

3.8 aod conversion

Reply #11 – July 27, 2008, 12:07:06 AM

thats interesting as im sure ive seen computer codes specific to AOD trans issues somewhere. if that were true wouldnt that mean the ecu plays atleast some role?
i hope im not confusing this with the a4ld trans.
i need to get my computer working again so i can research this stuff properly:mad:

3.8 aod conversion

Reply #12 – July 27, 2008, 07:09:25 AM

Quote from: Ductape91;229282

thats interesting as im sure ive seen computer codes specific to AOD trans issues somewhere.

Maybe in a dream... :slap:

AODs were first used in the '80 models, long before the first computer controls were applied to a transmission(or for the most part an engine) ... A4LDs are partially controlled by the EEC and the AODE/4R70W are fully computer operated...

3.8 aod conversion

Reply #13 – July 30, 2008, 07:04:26 PM

i hate getting bum info so to correct myself,
i was unintentionally referring to the AXOD(some py fwd trans), not the AOD. that does have codes.
sorry for the confusion there as the info i was basing this from was incorrect.