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Discussion Starter · #1 ·
Alright, I am buying some Roush Axle Backs at the end of the week and will be switching my 3.90s (were in the car when I bought it) to something a little less whiny. I want something that's going to give me a little bit of an edge but not so much that I have to be in 6th gear at 2,500 RPM's at 65 mph. I am leaning toward 7.73 strongly, but not if they are going to drone. I am aware of 3.55's but don't really know much about them. My real focus on this is to have my mean sounding exhaust, my strong launch and better gas mileage without the annoying drone from exhaust and whine from gears.

Help me out here guys, my wife's already told me that whatever I buy, I'm stuck with.
 

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Alright, I am buying some Roush Axle Backs at the end of the week and will be switching my 3.90s (were in the car when I bought it) to something a little less whiny. I want something that's going to give me a little bit of an edge but not so much that I have to be in 6th gear at 2,500 RPM's at 65 mph. I am leaning toward 7.73 strongly, but not if they are going to drone. I am aware of 3.55's but don't really know much about them. My real focus on this is to have my mean sounding exhaust, my strong launch and better gas mileage without the annoying drone from exhaust and whine from gears.

Help me out here guys, my wife's already told me that whatever I buy, I'm stuck with.
I have the 3.73s and at 65 I'm cranking about 2000. I love the gears I wouldn't ever get rid of them. If you want better mileage get the 3.55s
 

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Discussion Starter · #4 ·
I had Outlaws but got rid of them because the drone was so bad. Granted, that was with my 3.90s.
 

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Discussion Starter · #5 ·
I have the 3.73s and at 65 I'm cranking about 2000. I love the gears I wouldn't ever get rid of them. If you want better mileage get the 3.55s
The gas mileage, I would imagine, isn't that bad with the 3.73s. My main concern, though, is the noise. I am really just concerned with the combo of 3.73 + Roush Axle Back = Drone. I really do want the 3.73s, I just don't want to be stuck with the noise. She's my DD after all.
 

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The gas mileage, I would imagine, isn't that bad with the 3.73s. My main concern, though, is the noise. I am really just concerned with the combo of 3.73 + Roush Axle Back = Drone. I really do want the 3.73s, I just don't want to be stuck with the noise. She's my DD after all.
its awful
 

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Discussion Starter · #7 ·
its awful
Is it worse than it would be with 3.90s? That's what I have to deal with now.

Btw Bushguts, your car's quite lovely.
 

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I changed from 3.55s to 3.73s and saw little to no difference in mpg. I love the 3.73s. Best all around gear. I average 17-19mpg consistently. I have seen as high as 26.5mpg on the highway. Good luck!
 

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I now have 73s and I have no drone .I play the radio at normal volume I barly hear my exhaust untill I down shift
 

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Discussion Starter · #11 ·
Alright, you talked me into it. Roush and 3.73s it is. :)
 

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Discussion Starter · #14 · (Edited)
I have 3.73 with o/r xpipe and pypes super system and at cruising speed in 6th I can barely hear it.
Beautiful car, bro.

No it's not... I get like 20-21 on the high way and 17 around town
That's what I thought. The gears I have now are steeper than 73s and I somehow manage to get decent mileage still. It has to get better lol.
 

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As long as you don't go FI 373s but I have 331s and I love them for my application!
 

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Whine from gears is setup error, period. 8.8s are notorious for whines with steep gears but, that's because of the slap-dash setup on the factory line.

A shop that properly patterns the gears on load and decel should have no issues with whines.

The way Ford does it is slap the gears in and bang the pinion nut to a specified torque, job done. A crush sleeve sets up the backlash. This is no biggie with 2.73 gears but can introduce enough error for steep gears to whine.

I patterned mine when I pulled the cover to change the fluid and yep, pinion is too deep, according to my measurement. Hence the slight whine in a narrow speed range on the highway.
 

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Roush with stock cats has zero drone.

With O/R X or H is another story. If that is a plan for the future, 100% recommend Borla S-Types as there is zero drone with O/R X.
 

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Just to be clear, drone from the mufflers can't be cured without other muffs but, gear noise is install fail. Setting up 8.8s is a PITA, because of their design but, take your time and do it right and it can go well.

I find it pretty annoying that Ford hasn't figured out an answer to this, despite having 8.8s in vehicles since 1983.
 
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