The average rebuild (commercial) on the AOD lasts for just under 30000 miles. (based on industry records (ATSG) for the last 25 years) I've got to agree with these figures. I have had two AOD's rebuilt, a 92 T Bird and a 93 Explorer. The 93 T bird had about 90,000 on it when it went out, and had 120,000 on it when I traded it for the 93 Explorer, which had 190,000 on it when it went out. It only lasted about 20,000 before it went out again. We drove it without OD the last year before we traded it, racking up another 8,000 miles....
Now that I know these transmissions are weak I am going to forget about running one. I thought they were a good tranny for a mild hotrod as long as you didn't do much burning out or racing
They are very good transmissions. PaulS has had a bad experience with them but if you ask him what he put in his boys bronco he will tell you it is an AOD. but he had to do this and that and that whatever. If you really want to know about it talk to 71 gold. PaulS is biast to what he likes and he is too willing to downtalk anything else (hence the T.L. and the pinto statement). Many people run the crap out of them for 100+ thousand miles without a complaint. Look at everything that is recommended to upgrade the C4 like installing extra clutches and wider bands and staying away from the pre 70 something c4's because they were weak. You will see that is the same you have to do to the AOD, don't take one or two peoples word on it when so many other people are saying great things about them. Look on the 5.0 forums very very few of them go back to the C4 and that is only in race applications. The rest of them either run t5's or AOD's without any problems.
Markso125, You obviously know nothing about me and you assume because i explain the differences between the AOD and C4 that I don't like them. On the contrary, in the right application they can be as strong and dependable as any C4 built for the same application. My son's Bronco is just one of the AODs I have built - and his Bronco came with it in already - it wasn't a swap. He wanted me to make it able to stand up to the kind of 4-wheeling that he does - low speed, high torque loads from a stock 302. I installed the same components that I use for a 400 hp engine, modified the valve body to have posistive 1,2 shift and hold and then once into drive it shifts into OD automatically. There was no way (after the mods) to keep it from going into OD but he wasn't going to use it on the highway much - just the dirt roads to where he plays. It cost him $1200 for all the parts and machining. He thought he got a great deal and he did. You said, "Look at everything that is recommended to upgrade the C4 like installing extra clutches and wider bands and staying away from the pre 70 something c4's because they were weak." Extra clutches are added in the same clutch packs, there are no wider bands for the C4 - they come with 2" bands. The pre70 C4s use a smaller input shaft that is true - and it makes it weaker, but the primary reason is the the valve body and case have different passages than the rest and no one makes the manual valves for that series. It is a simple matter to bolt on the early 5 bolt bellhousing and switch to the stronger 70-up C4. From 70 and later I can use any of the components from one C4 to another - they are all the same with the exception of the number of clutches the drums hold - they can all be machined to hold more or replaced with other stock core units. On the other hand to replace the cast drums in an AOD with the later steel drums (which hold more clutches) you have to replace nearly half the internals including the planetaries. The shafts are not well lubricated and they require machining to provide vital oil to the planets. That means that you need to either buy the replacement parts or you have two transmissions (one of them a AODE or 4R70W). These are not required on a stock engine of 120 - 160 hp. Those that have bought AODs from me have had zero problems with theirs. They can be made to handle a great deal of power, it is just more expensive than a comparable C4. Quit saying I don't like the AOD! I love the AOD it just isn't a magical answer to everyone's needs.
As a current technician......I can say the AOD and its successors are decent transmisions....You can spend gobbs of money making one hold up.....or you can buid a c4.....cheaper.....The downside no over drive.... PaulS is correct in his summary of differences and I can not add to his deep knowledge on the subject..... I have seen many AOD crap out on stock stuff......In stock form they are not all that and bag of chips.....Built correctly they are good units but I still wouldn't use one for a serious HP machine......unless I wanted to drive said 2000hp @ 2400rpm monster on the street just to say I could I never got the impression PaulS was biased just an informed person with real world XP beyond one AOD that hasn't seen 100k of abuse.....
Lets examine these "averages" a little closer. The C4 average is based on many years/versions of C4 that were produced including over a decade of the 70 + version which is the desired core to start with. I would assume a commercial rebuild of a 70 or later C4 would last, on average, longer than 75K miles. Similary, the 30K average for the AOD is based on commercial rebuilds of ALL AODs. However, the average is skewed greatly with respect to the desired versions (say 91-93). Likely, the early AODs failed at a very high rate inthe early 80's and even the rebuilds throughout the early - mid 80s had a high failure rate (less than 30 K on average). I will therefore assume that a commercial rebuild of a 91-93 (93 preferred) AOD will last, on average, much longer than 30K miles. Earlier in this thread, the AOD was said to be OK for stock power in the 120-160 HP range. I would have to assume that good original or commercial rebuilt 90's AODs can reliably handle more HP than this as well. Unfortunatley, the best of the AODs were only produced for a couple of years. Bottomline is, AOD choice should be based on your individual application and circumstances(duh). If you have specific usage that includes highway cruising (daily drivers especially) than the AOD will likely provide return on the investment in fuel savings as well as reduced wear on the engine, making it a valid choice. This is assuming you have a non-stock rear end gear ratio, otherwise the benefits are diminished and overdirev may even put your engine in a less efficient cruising RPM range. If/when you decide to go the AOD route, be patient and find that 93 van AOD (or similar) and move forward. My circumstance is a little different in that I am building a street/strip MAV with solid but manageable HP (400) and want to drive to and from the dragstrip that is 40 miles one way, while running a 4.11 rear. I chose the AOD to get me to and from the track without having to turn 3K+ RPMs ... AND the extra cost for the AOD is much cheaper than the cost for a trailer. Also, I have no room for a trailer at my house. OH yeah, and I patiantly waited and found a low mile B&M AOD rated to 450 HP for $450. On the high HP end of the AOD swap subject, honestly, if you are running 600 HP, then A) you really have a race car and aren't likely to be "cruising" down the highway and thusly don't need an AOD, and B) have a lot of money tied up in the engine and rear and roll cage, etc. and I must then assume will shrug off the $1000 extra cost for the AOD if you were to decide the AOD is for you.
anyone ever consider an adapter plate to bolt up a 700r4? theres alot of hot rod guys in my area that love those. they were the stock OD tranny GM was throwing in during the 80's
They used this transmission up into the 90s They are ok trannsy, had one in my GMC 4x4 Alot of guys, use the 200r4 because its lighter weight and can be built to a decent strength. Buick turbo charged car guys love these trannys.
First PaulS yes the impression you give to me, and some other people, from what I have seen posted here and in other topics is that you don't like it. Like I posted earlier this argument has gone on for awhile and it seems to continue in the same direction even in this post. In the forums since I have joined I have seen people putting viper motors in Mavericks with applause for being different. I have seen the 4 cyl being put in with people excited in how it turns out. Even the Ls1 motors in Mavericks don't recieve as much of negative response as you give the AOD's. When someone has a problem with a carb or timing everyone puts their input in to help them fix their probem and to get their cars to run better. Nobody, especially those of us who have installed them want to hear how bad you think they are. If you know so much, tell us oh great Obi Wan, what we need to do to improve them. Honestly I think there would have been less of a negative response from you if he would have said he was going to put a Tourqueflite 727 in instead. The AOD may not be a magical answer to everyones needs, neither is the C4 or the T5. But you should quit discouraging the use of the AOD and start helping make it better so it won't fail.
FishnRace, Excellent advice on the AOD. Glad you could find a good one at a cheap price. one concern that you missed was that if you have, say, a 3500 rpm converter and the OD puts the rpm at freeway speeds below that point then you have the added problem of heat build up. One man I know is having this problem now and has decided to mount a pump and cooler to his pan (in addition to the two large coolers he already runs because his transmission runs 230F just running down the freeway.
PaulS - Agreed on the converter rpm rate and cruising speed issue. which is something to be considered for ALL automatic transmission owners when increasing gear ratio and converter RPM. I personnally also need more educating on the lock-up vs. non-lockup converter subject. From what I understand, having a lockup converter can limit how much HP can be applied in OD before eminent failure occurs. However, if one can run a lockup converter (because not not inputting too much HP), then there won't be the huge converter slippage and heat build up is reduced. How far off am I on this subject? - Jamie
