First question: Would an AOD out of a drivtrain-donor '87 T-bird have a "computer" all its own? I parted the bird and was going to convert the 5.0 back to carb and points, but ended up selling it to my neighbor who wants to use the EFI and ****, etc. I was gonna give him the EFI stuff anyway, so I carefully extracted the wiring harness and computer, etc. But his Dad's buddy tells us there is ANOTHER compooper for the AOD. Is this true??? If so, what the heck does it do? I only saw two electrical connections to that thing when I took it out, I had ***umed the were speedo, and reverse lights. Could someone shoot me a picture of one? I saved a milk-crate full of funny black boxes and residual wiring harness, and have p***ed along at least one mysterious box taht may be it. But if I could have a pic from "someone who knows" than it would put the discussion to rest. Second question... we gotta swicth gears (figuratively) to GM stuff: How different (or the same) would a saginaw 3-speed that sat behind a 4cyl from a Vega be... ...than one that sits behind a big 6cyl in a full size pickup? Any difference in strength? Or just gear ratio? Year-model unknown for the Vega, but it has an iron head and an aluminum block (yeah, no sheet mang) and points ignition. The truck is a 1980, longbed 2wd. Also, do those trucks frequntly have column-shifter troubles that prevent them from getting third gear? Thanks for all, Jason
87 Aod is non electric control 93 up is.Sag will work but you need to switch front bearing retainer.Truck has bigger hole in bellhouseing.
Usually if you can get it into second, then you can get it into 3rd. The tough one is the 1-2 shift. but it wouldn't hurt to look at the linkage and make sure it's not coming apart, or misadjusted.
So, a busted pressure plate/ throwout bearing might be a very likely culprit? Either way, trans is getting pulled out!
Sags came with a number of different first gears. The Vegas usually came with the lowest first gear. You can tell the ratio from the grooves on the input shaft: # of grooves 1st 2nd 3rd 4th Notes: 0 2.85 2.02 1.35 1.00 1 2.56 1.81 1.37 1.00 Third gear on cluster has 25 teeth 1 2.56 1.81 1.44 1.00 Third gear on cluster has 21 teeth 2 3.11 2.20 1.47 1.00 3 3.50 2.48 1.65 1.00
What is the wire for coming off the trans then, is it for the converter lock up? It's a 4 pin plug on my 88 AOD. Speedo was still cable. Thanks
AOD does not have a lockup converter. The connector you see is for backup lights & neutral safety. These ******s have a HUGE problem w/ sticky governor & valves in the valve body. Also must be set up CORRECTLY w/ a pressure guage(No guessing on this one). DAVE
The hard part is that they were never set up to work with carbs, as, instead of a kickdown lever, they use a throttle valve, that is activated by a rod or cable, depending on year and model. After putting a B&M shift improver in my AOD, I fabbed a linkage to the Edelbrock carb (actually had to add 3" of length to the stock TV lever. Then I had to transfer that over to a Holley) then used that for the adjustment. Worked perfectly first try without using a pressure guage, and was flawless for the 5 years I had the car.
Ooops, wait a sec... The fragged trans in my truck is a 3spd, (also with a fragged main bearing carrier... the one sittin in my garage is a 4spd... (with too-small of a main bearing carrier to fit in the truck bell... Ed, do you have another chart showing the 3 spd ratios as well? I know 3rd is 1:1... I think the 4spd is a good keeper for the back-burnered t-bucket, I'll try to find another 3spd for the truck...
Sorry, I don't have a chart for the 3 sp but I think it is the same as the sag 3 & 4 sp share the same input shaft. That means the first gear is the same for the 3 & 4 sp trans if you go by the number of grooves in the input shaft. A tip for IDing a Vega/Monza trans: the early ones have three holes crosswise on the bottom of the tailshaft housing to mount a large weight used to dampen 4cyl vibration. Sometimes you will see the weight still attached. It looks like a stack of steel plates in a sandwich on a bracket going to the bottom of the tail housing. Later Vega/Monza trans have a mount for the center trailing arm for the rear end, which uses the same holes for both the weight and the arm.
Yeah, I remember a Monza in auto shop cl*** with no engine/trans... we'd have to push it outta the way, and when you hit the brakes, BOOM, that trailing rod would hit the tunnel loudly. I think my 4-spd is the earlier one, I do think it has the three holes, and the engine that came with it has points ignition...
Sorry i dont know to do margins so here goes on the 3 speed no lines 2.85 and 1.68 , 1 line 2.54 and 150, 2 lines 3.11 and 1.84 and last is 3 lines 3.50 and 1.89 I hope this helps.. of co**** high is 1 to 1 The most common is the no line unit 1.68 second. I hope this helps some....Bobby...
The Jalopy Journal
