Thread: Not to happy with AOD trany.

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I've got a Aod trany in my 70 Ford pick-up and its a real dog.
At 75mph it's only turning about 1500 rpm's with it's fuel injected 302.
See the computor the motor & trany all came out of a 89 lincoln.
Well I have a small block C-6 and a C-4 laying in my shop and would
love to stick one of those in to re-place the AOD.
The problem is how would I hook up the kick down since the factory
intake bends over to the left {towards the passenger side} and the AOD is controlled by the computor. This truck does not need to run more then about 80mph. Besides the AOD Trany seems to slip under hard exceleration. Any ideas for the kick down linkage.

Kurt

First, you're not going to gain much performance with the 3 speed, you just lose the OD. The ratios aren't much different, nor is the HP drain.
Second, the computer is going to miss the inputs from the trans. The speed sensor can be put on the 3 speed, but it won't be shifting when the 'puter tells it to.
I'd just change rear end gears to get the RPM's up. With gas prices these days, that OD is nice!

Thanks R. Pope, that was my guess too. What is the present rear gear ratio? lt seems to me it would be a lot easier to lower the rear ratio by a tooth or two than to change the trans and lose the OD. As far as the slippage goes that may be a mismatch with your stall rpm and the low rpm in OD. If the rear gear were lower you might get above the stall rpm and that would cure the slippage?

Don Shillady
Retired Scientist/teen rodder

Thanks guys, I'm gonna have to see what the stock rear end gear ratio was
for the lincoln in 89.

Kurt

Any way to put the overdrive on a separate switch like to late model Fords? In my work, we used Ford Crown Vics and only use the overdrive on the freeway.

Don...stall speed doesn't enter the picture with the Ford AOD. In Drive and OD the power goes through a shaft that splines into the front of the converter. Solid drive, no slippage involved. Like an old ClutchFlite!
Gasser....If you want to run in Drive, just shift it to Drive, no switch needed.

I have a '87 Mustang with a 302 & AOD, with a 273 rear ratio . it also turns 1650 @ 75, it's a real dog! but a high top end. (mine is lowered 1 1/2"front, 2" in rear, for handleing) The dogest car I have every owned! I have check on the Mustang sites and they say that the best cure is gears, to drop to 373 or 411's with a AOD, for everyday driving, then add a stall if you want more out of the hole.
The same car & gears but a stick is night & day differance.

My .02 worth.
Pat

I believe your truck should have a nine inch.It should be pretty easy to find gears or a complete pumpkin for it.
Don,t forget your tire size plays into that also.