7.5 traction-loc gear ratios

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7.5 traction-loc gear ratios

June 16, 2006, 11:03:30 PM

I've got a 7.5" Traction-Loc rear end with 2.73 ratio in my 87 sport. I'd like to have the gears changed to either 3.45 or 3.73 ratio, which I understand are available for the 7.5 Traction-Loc. My question is what RPM's should I expect at lets say 60 mph with either gear set with an AOD in 4th (OD)? What are your experienced advice? Some feedback on the 3.27 would also be appreciated. Thanks in advance!

7.5 traction-loc gear ratios

Reply #1 – June 17, 2006, 07:47:59 AM

my friends mustang that is auto with 3.73s is around just over 2k at 65. its pretty nice because his car is at the beginning of his power band at highway speeds, so it realy dosnt even need to down shift to get up and go. nice for passing people too. now my mark has 3.27s in it and its somewhere inbetween 1500 and 2k at 65 i think closer to 2k, iv only driven it once on the highway so far lol, i cant tell how nice it is tho because of its weight, but its deffenatly more responsive than when i had the 2.73s in my tbird with the ho. hope this helped

7.5 traction-loc gear ratios

Reply #2 – June 18, 2006, 07:20:01 PM

Hi
HERE IS SOMETHING THAT MAY HELP YOU FIGURE THIS OUT .UNFORTUNATELY YOU GOT TO DO SOME MATH.
STEP1...NEW GEAR RATIO/OLD GEAR RATIO=RPM FACTOR
STEP2...RPM FACTOR X ORIGINAL RPM =NEW RPM
EX. 3.73/2.73=1.366
1.366 XORIGINAL RPM OF 1800=NEW RPM OF2459
HOPE THIS HELPS?

7.5 traction-loc gear ratios

Reply #3 – June 19, 2006, 12:05:49 AM

Thanks Nate and JRP. This certainly helps me lean towards deciding on 3.73 ratio. I guess what I need to figure out is what do I want from this car? It's not the daily driver. Actually its become the GARAGE QUEEN that gets taken out on cruise nights, show n' shines and dates with the wife. I don't think I'll ever mod it to race (for now), but its sure nice to leave rubber behind now and then. That 2.73 isn't the best set up for that. Mind you at the price of gas these days, 1400 rpm or so at 60 mph does make some sence (or cents)LOL. Any other comments or experiences still are appreciated.

7.5 traction-loc gear ratios

Reply #4 – June 19, 2006, 01:16:04 PM

Garage Queen eh??

It aint no problem then, get you some 4.10s or be a real man and stick some 4.30's in her ass... I have a 3.0 Aerostar van that has 4.10s from the factory...

7.5 traction-loc gear ratios

Reply #5 – June 20, 2006, 12:30:30 AM

Ha! Ha!
Ya, I had a 97 3.0 Aerostar with 3.73 as the family bus. "The Little Engine That Could" needed all of 3.73 to get out of its way. Wish I had the 4.10 then. I sold it to get an 03 Explorer. Got to say I miss all that space I had to haul things. As weak as it was it did prove to be "bullet proof" reliable. My daughter thought the Explorer looked cooler. (Wish she'd pay the gas!)......4.30 eh? Must scream on the highway. Oh what to do???

7.5 traction-loc gear ratios

Reply #6 – June 20, 2006, 09:18:03 AM

Sr Bird
My 84 bird gets the same use as yours does and Im in the process of making a few changes like you. Im looking for fun around town with some reliability as well.I am going to swap the 3.08 for 3.73 (7.5 rear)(I got a posi unit from a bronco 2) .I think that will will work well with the aod,keep the rpm in range to suit the power band of the 5.0 L. Boost the HP of the engine to approx 300.
Jrp