need someones input here...trans expert...

[pro street rich]

Well a couple of us were sitting around the other day bench racing and the pro and cons of the lockup or non lock up convertor were talked about. The big question came down to which one is better for the street and some trips to the track.
We are talking about the "AOD' trans here. I would like to hear from some of you as to which one is better. I know where I stand, but just want to make sure I am on the right side of this one....Thanks......Rich

[90sc35thann]

Well everyone is going to have their own opinion on this one. For me personally the aod does real well with a non locking converter. The aod locks up as soon as it hits 3rd gear which is why it feels like you threw an anchor out the window once it hits third. No way around it unless of course you use a non locking converter. The manufacturer of the converter has much to do with the quality and durability of the converter. Without lockup you are going to produce excess heat and this isn't always great for the life of the transmission not to mention you will see a reduction fuel economy. I have had many aod's without lockup and loved every one of them for the fun factor and the gains that I realized at the track. For me I will tell you that I would go non lockup every day of the week and twice on Sunday.

[neverfastenough]

IF you make enough power direct drive in 3rd wont feel like a boat anchor

[90sc35thann]

Originally Posted by neverfastenough

IF you make enough power direct drive in 3rd wont feel like a boat anchor

I was making plenty of power. It may be less noticeable with gobs of power but it is still evident and it does make a difference. But then, as it always does on the boards, circles back to a difference of opinion. :-)

[XR7 Dave]

It's pretty simple. Direct drive is weak, so if you make enough power to overcome the drag, then you are in danger of breaking parts every time it shifts. Raising shift points with valve body mods and governer changes can help, but it comes back to the same thing.

If your car is pretty stock then a tight non-locking converter drives 100% better than the DD unit, you just won't have a high stall. If you run the non locker with 3.73 gears, then you won't really miss the higher stall. Win all around as gas mileage won't really suffer noticeably and the car will be quicker.

If your car is a long ways from stock and you want to go fast, a high stall DD sounds like a good idea until you consider that a hard 2-3 shift can and will tend to shear off the small input shaft, hardened or otherwise. Some people have had success with this but it's sketchy at best. It also means you have to run a weak converter which is subject to ballooning at high rpm which won't necessarily show it's ugly face until you loose engine bearings or the converter starts to loose efficiency due to case distortion.

I have said differently in the past, mostly because I was relying on other people's statements rather than speaking from experience but as my experience with AOD's has increased (much to my chagrin), my appreciation for the DD converter has diminished significantly.

Now a properly locking converter (triple disk clutch type) is significantly superior to an open converter. Problem is you have to run a modern transmission to use this, of which the AOD is not.

[kenewagner]

Since I have the non locking TQ converter, I can say it makes a lot of heat runs hard at the track, performs crappy on a dyno for numbers, hasnt broken anything in the transmission yet Seems to me years ago the story was if you wanted to go fast down the track you had a nonlocking TQ converter. Than It seem that most people felt it gave away to much HP on the top end due to slippage but didnt break things on the shift. Mostly I think its about how the car is setup and hp its making and other factors. I cant really afford to be tearing trannys apart to fix them so I guess I will live with poor dyno numbers and have a tranny that stays together.

Ken

[bowez]

I have a non DD convertor and I can attest to the high heat--looking at new radiator or bigger cooler and or fan. I like my TC (have 3.73s) and picked up 3-4mpg with the new tranny and TC.

IMHO if you are looking and building your AOD seriously look at going to a 4R70W. A 4R wasn't in my budget but am pleased with what I have--has lasted longer than any other AOD build (2 prior) and taken more abuse too.

[90sc35thann]

Originally Posted by bowez

I have a non DD convertor and I can attest to the high heat--looking at new radiator or bigger cooler and or fan. I like my TC (have 3.73s) and picked up 3-4mpg with the new tranny and TC.

IMHO if you are looking and building your AOD seriously look at going to a 4R70W. A 4R wasn't in my budget but am pleased with what I have--has lasted longer than any other AOD build (2 prior) and taken more abuse too.

Nice honest assesment.