We come stock with a 3.00 diff ratio right? If I go AOD i'm worried it might be too low a gear? Will it? If so



I'm thinkin of just changing the ring and pinion (BC that's all I need to do right?)



How hard is it to correctly change the gearing, and what all do i need, rough cost est?

William



1957 Ford Fairlane 500

292 Bored .30 over

Fordomatic

You might start off by mentioning what year and model you have?? For example a '55 Ranchwagon would be different than a '57.





Johnson Rod



Southern California

I got to thinking about it, and not only would I have to change the gears correctly, but that'd also include changing the speedo gears and everything else... If the facts i've looked up are correct.



I'm very curious what the optimum efficiency range is... (1900-2200 RPMs?)



The fordomatic has a 1.00 final drive, the AOD had a .67.... So the numbers would equate to...



(This is with a stock 3.10 57' rear and G78-14 tires)



Fordomatic AOD AOD with 3.70 gears



45- 1755 1176 1403

50- 1950 1306 1559

55- 2145 1437 1715

60- 2340 1568 1871

65- 2535 1698 2027

70- 2730 1829 2183

75- 2925 1960 2339

80- 3120 2090 2495

85- 3315 2221 2651

William



1957 Ford Fairlane 500

292 Bored .30 over

Fordomatic

  It depends on how you look at it, or why you want an AOD.

Do you really want overdrive? If not, why not stick with a 3-speed Cruise-o-matic?

Do you want an AOD so you can change R&P and use the first three gears at a lower ratio for more torque?

My Stang has a 4.3 gear w/AOD & 351W.  I can't hook until third gear.  It's not a car to take long trips in.

So, what car do you have, what engine, and what use are you building it for?

-  Dave

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

If you have a Ford 8 inch or 9 inch you only have to change the pumpkin (3rd member) for the cost of the unit you buy. IF THE YOKE IS THE SAME.  I suggest that you install the AOD first before you switch rear gears. I had a 1985 Tbird with a 5.0 and AOD that had a computer that gave instant MPG. I think the rear was 2.41 and at 75MPH I got a consistant 28MPG  mile after mile. If you want more power you shift out of O/D back to drive. The AOD is weak in O/D and you can not tow in that gear. Read up on the AOD at click click racing forum. Pete

Well I'm wanting a nice lil cruiser.

I'm gonna have a 292 with a 450cfm 4brl holley with a 265-S (i think that's right,it's quite mild) cam.

I want the AOD bc it will be a daily driver and would love some mpgs...

I'm not looking for a racer, But I would hope this v8 will accelerate if need be...

It's 20 or so miles almost all interstate (40 round trip) so the low rpms when cruising would be nice...

I jut want to make sure the RPMs aren't TOOOO low,if that's possible???

William



1957 Ford Fairlane 500

292 Bored .30 over

Fordomatic

Your 3.0:1 gear will be perfect.  Don't change your speedometer gear ratio, either.  If you decide you want stump pulling power, you can always go to a 3.55 or 3.72 with some top speed sacrifices.

The first three gears are the same as older tranny's.   Overdrive is not for mountains or high torque situations.  It easilly downshifts when you put your foot down.   Overdrive usually kicks-in after 40 mph or so.  That is nearly expressway speed, anyway.  Your car will purr on long trips. 

A word of serious caution:  Make sure a competent, experienced, transmission mechanic sets your AOD up for you.  I have seen guys install a new AOD without setting the linkage properly, they only last about five minutes at idle speed.  A hydraulic gauge verifies pressure while the linkage is set-up.  A NOTE ABOUT TV PRESSURE ßClick on this and read the second paragraph.

Hope this helps.  - Dave

Royal Oak, Michigan (Four miles north of Detroit, and 12 miles NORTH of Windsor, Canada).  That's right, we're north of Canada.

Ford 292 Y-Block major overhaul by simplyconnected

Yeah i know how that is, i bought a crown vic with the AOD band burnt out bc of the linkage being screwed up :-/

William



1957 Ford Fairlane 500

292 Bored .30 over

Fordomatic