Best axle ratio for 5.0 AOD

Discussion in 'Fox 5.0 Mustang Tech' started by David B, Oct 23, 2008.

  1. Now that I have my daughter's new 92 lx running, I plan to swap out the gears. I see most everyone installs 3.73 or 4.11 for 5 speeds, but what about for an AOD? My previous 5.0 was a 93 Cobra motor in a 65 Mustang Fastback, Tremec TKO, and a Ford 9 in rear axle with 3.89s, which was fine with the stick. This car (the 92)will not see any track time, just street miles, but about 50/50 city and highway, with about 300 miles a week as a target. What are some reactions from those who have installed 3.55 vs. 3.73 in an AOD car? Thanks
  2. i have 4:10's im my notch (aod with shift kit)which when it was just a bolt on car was great around town but on the highway the drone killed me i saw about 2800-3000 rpm's while on the highway with 245-50's all the way around.i am looking to put gears im my 90 and since the car will be just a cruiser i will go with 4:10 or 3:90 if i get lucky. phil
  3. A few years back I had a stock 92 gt with an AOD and 2:73 gears . I had installed 3:73's in it and always felt that I should have used 4:10's. It would have handled them with no problem. I just didn't feel the 3:73 were that big of a change from the 2:73's. You would think it would be radical, but it wasn't. Most people you talk to will suggest 4:10's with the AOD. Even stock. You may however want to install a high speed govener kit from TransCo to raise the shift points to better suit the new gears. I would also suggest checking out Click Click's web site, they have a ton of great info on AOD's on there. DON'T FEAR THE GEAR! LOL. Dan
  4. 3.73's, 3.90's, 4.10's

    I have 3.73's and they are too steep for me. I actually wish i went 3.55's
  5. Mine has the stock 3.27's i like this gear ratio...When i start doing some basic bolt ons and run a 100-150 shot i think these gears will work perfect for a strip/street car....But it i had to go with gears it would be 3.55's....
  6. AOD with 4.10s feels and performs like the perfect gear. My Dad is 74 years old and loves those gears in his '92.
  7. but what about gas mileage with 4:10s?
  8. City it might go down because of the less load on the engine to move the car around, but on the highway, the increased RPM does use a little more fuel.

    It's why i hate my 3.73's. There is no top end. I-95 near me is a 75-80MPH road and to hold that speed i need to do 3000RPMish in OD. There is no TOP end, i need to kick down into D in order to go WOT and you can't go WOT in you are limited to 100MPH pretty much (105 i think actually)

    When i race at the track, the car pulls great off the line but then feels like it runs out of gearing at the end.

    I'm noy '03, i LOVE my 3.27's and have no desire to change. In my 5.0, i would gladly step down to 3.27's ot 3.55's.

    I don't regret 3.73's, but since i do a lot of highway miles to go to cruises and such....3.55's all the way
  9. I run 3.55s and like them for city/hwy. 75MPH is right at 2500 RPM, its got decent guts around town too.
  10. if the combo is mild i would say 3.55s, maybe 3.73s max

    sure those LOW gears like 4.10s give that SOTP kick in 1st and 2nd, but on a mild combo it puts you out of your powerband way to quickly. so the car will run out of steam.

    and like 5L5 said, you will be limited to 100 mph or so. your top end will be gone.
    lower gears are better suited that can turn some RPM to actually use the RPM range the gears are going to put them in.

    IMO gears arent the endall of all performance like they are hyped up to be, they do help some, the stock 2.73s are WAY too high of a gear for a street 5.0

    if you want more stuff you in the seat feel, actually increase the power output of the motor, feels alot better that way.

    i'm fixing to swap to 3.27s in my car for my turbo setup, i cant wait, will help load the turbo better and street driving is going to be alot more fun.
  11. Thank You

    Thanks for the all the honest input. I have a set of new 3.73's that I was going to install in a prior T-5 car, but never got around to it. I felt like they would be too much. I do have a used set of 3.55's from an 8.8 out of my F-150. I think I will go with those.
  12. I put 3:73's in my AOD car. It made the car 100 times better and feels like the perfect gear.
  13. The key being "your daughters car" !! Having been there... I think your choice of the 3.55s would be the best. There are Boyfriends/ Gas cost/ and if it is too fast.. that is a whole different ball game!! just a thought.

    Just me.......................................

  14. I have put 4.1 in my aod. before I did that. I use to drive the car in over drive lock out. not using 4 gear at all. It stops me from going over 90 much. Helps car be fast for me.
  15. On a bolt on car 3:55 is perfect all around, 3:73 will give you the quickest et, 4:10 is good for about 1/8 mile only, I had 3:55 in my 92 lx vert & it ran 14:40's with O/R H-pipe, flows & 14 degree timing. No other upgrade.