AOD Getting Nasty

[Nixon1]

Just a few questions as to normal behavior for a higher mileage AOD tranny. This tranny, if original, has got 147,000 miles on it and it feels non-rebuilt. Shifts into 2nd fine, but 3rd and Overdrive are total dogs. For the shifts to be bearable, I have to get the rpms above 2000 before it shifts. Below 2000, it's a hard, nasty, THUNK/kick/dull thud noise shift. That's true for both 3rd and Overdrive, although the Overdrive shift is also a farther one. Is this normal behavior for a higher mileage AOD, or is it well on its way out? TV cable was well out of adjustment for a while..tranny shop just installed a new one and upped the pressure a tad for slightly firmer shifts.

Thanks everyone...this tranny really worries me...I've never dealt with one so sloppy. And I used to complain about my 700-R4...that thing was cherry compared to this.

[TwiLighTBluEGT]

Didn't you post of stangnet?

[Nixon1]

Never been to Stangnet...

[TwiLighTBluEGT]

Oh ok because someone posted there the other day saying that their 147,000 mile AOD tranny was going out.

Oh yeah, by what you say about yours, it sounds like its going.

[Nixon1]

Yeah...that's what I figured...no surprise to me... Hopefully it'll last til I can AFFORD to fix it the RIGHT way....(rebuild with good shift kit, new valve body, and hurst or similar make ratchet-type shifter)

[90GT Vert]

I say rebuild it, get a one piece input shaft, a nice non lockup stall, a good manual valve body. somewhat like what we are running, when we did the trans. work to ours it was a different car.

[Nixon1]

One piece input shaft..what's the advantage of this? Handles more power?? Also, are all stall converters non-lockup? I was hoping to get a lockup to get an extra couple miles per gallon around the city cause my gas mileage is horrific.

[90GT Vert]

a one piece input shaft can handle more power then the stock 2 piece input shaft. we have a lockup converter, a non lockup "flashs" and whatever your "flash speed" is at it won't go until it reaches so many rpms. E.X, if you have a lockup 2500 stall converter, when you reach 2,500 rpm's you will start going. on a lockup its just like the stock one, but you can stall it up to more rpm's.

[Nixon1]

Originally posted by 90GT Vert
a one piece input shaft can handle more power then the stock 2 piece input shaft. we have a lockup converter, a non lockup "flashs" and whatever your "flash speed" is at it won't go until it reaches so many rpms. E.X, if you have a lockup 2500 stall converter, when you reach 2,500 rpm's you will start going. on a lockup its just like the stock one, but you can stall it up to more rpm's.

Sorry but you totally lost me...do you mean a stall converter car won't accelerate until you hit the stall rpm, whereas a lockup converter WILL?

[90GT Vert]

as far is i know thats correct.

[429mustang]

I just bought a 22-2500 rpm stall converter w/lockup. We'll see how it works in a week or so. Anyone know how to correctly set the kickdown cably for a 700R4 transmission? I hear you can mess up the trans pretty good if it's not set right, and that could have been the reason my old one went out so quick.

[HiFlow5 0]

Converters and transmissions can be very confusing, especially if your new to them!

OK lets define a couple things first.

Stall speed = a desired rpm range in which the torque converter forces fluid outward through its vains to engage movement, bringing the motor and the transmission together.

Flash stall speed = a certain rpm that is reached when the gas pedal is mashed to the floor. Flash stall speed is usually a higher rpm then normal stall speed.

Non-lock up = Say you have a 2500 non-lock up converter, when you accelerate the converter will spool up to the stall speed of the converter before movement happens. This will happen in every gear, and the converter will always be loose. Not coming close to that 1 to 1 ratio the stock converter has. (Good for performance, keeping the rpms higher for engines that have higher power bands.)

Lock up = For 1st and 2nd, the same thing happens as above in the non-lock up statement. Now lock up happens in 3rd and 4th gear, causing the transmission to be closer to a 1 to 1 ratio. (good for fuel economy and has lower rpm's on the free way. Lock up is controlled by the inner shaft on the input shaft of the transmission.

Solid or 1 piece input shaft = Like stated, just one piece, and is very strong compared to stock. The stock input shaft has 3 splines that control lockup and such.

These are just the very basic explanations, to help you understand what happens in these complex transmissions. There can be more said about automatics, and I'm sure that someone else will pick up where I left off. I just don't want to confuse you with a whole bunch on chaos and technical info. Hope This helped some!

-Craig

[Nixon1]

429: Haaa...never thought I'd hear someone mention a 700-R4 on these boards.. The 700-R4 has a TV cable run up to the throttle blade...it should have a little clip-type thing on the mounting bracket attached to the throttle body, behind the throttle blade..it has a metal tang in it. Never done it myself but supposedly you push in the tang and slide the cable HOUSING all the way inside the assembly..then release the tang, grab the throttle, and rock it to WOT, then release...supposedly it ratchets itself to the correct position. And yes, an improperly adjusted TV cable on a 700-R4 will blow it up...they're very pressure sensitive, especially when they get some miles on them.

[Nixon1]

HiFlow..thanks big time for that...I've got that down..feel free to move on to the automatic tranny any time..