2017 Mustang gear ratio change?

[EFI]

I assume that's Canadian dollars, which will be about $1200 USD.

Seems about right seeing as how the parts are around $400 and then you have the labor not only to R&R the diff but also to change out the gears.

Although not sure if it's a good idea for you to go to 4.09s when you're also going with the biggest turbos possible on the S550 chassis.

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[BmacIL]

Dude, you need to figure out wtf you want the car to be/to do and plan a build that actually works for that. You're multiple personality disorder over here with all the paths you're going.

 

[LxMike]

Other thread you said shop asked for vin and then told you that you have 3.73s and now you have 3.55's??

I agree with BmacIL,

You need to sit back and decide what you want.

 

[Hack]

If you are going turbo you don't want steeper gears. I agree with the others.

 

[Mikepol2]

For sure don't want 4.09's with boost. But $1200 US is about right if you're dropping the car off at the dealer and expecting to drive it away with 4.09's. There's a lot of labor in removing the diff from the car and then more labor to install the gears in the housing. If you are handy and can find someone you trust to actually install the gears, you can remove the diff yourself and give your gear guy the diff and the gears, then reinstall the diff yourself when the new gears are loaded in it. I did my 4.09's this way and total cost was $200 for the install labor (great price from a friend) and about $200 for the parts on Ebay.

 

[revinto7]

I'm not surprised it would be that high. It's quite a bit of work. Make sure they are using a good quality gear set.

its 400$ dollars us in parts and 250$ in labor , 1600 is rediculous

 

[Mikepol2]

its 400$ dollars us in parts and 250$ in labor , 1600 is rediculous

It's about 10-12 total hours of labor. 6-8 hours to remove the differential from the car and then reinstall it. Installing the gears into the diff is 2-4 hours depending on how experienced you are.

 

[revinto7]

It's about 10-12 total hours of labor. 6-8 hours to remove the differential from the car and then reinstall it. Installing the gears into the diff is 2-4 hours depending on how experienced you are.

i can have the Diff out in 2 hours have gears in 2 hours and back in 2 hours !!!! 6 -8 hours total

 

[Mikepol2]

i can have the Diff out in 2 hours have gears in 2 hours and back in 2 hours !!!! 6 -8 hours total

Like I said...depending on your experience. I did it one time and it was about 5 hours out and 3 hours in. If I did it again it would be less. The Ford standard service time is 12 hours total.

 

[Hack]

i can have the Diff out in 2 hours have gears in 2 hours and back in 2 hours !!!! 6 -8 hours total

Right. But that's internet bragging time, not Ford shop time.

 

[subbz]

If you're going for forced induction dont get 4.10s.

 

[Redline_Stang]

I found out today I have 3.73 on my Mustang already. Will switching to a 4.10 gear ratio be of a difference? Or would the switch not be worth it?

Or even going higher?

I switched from 3.73 to 4.10 in my 93 Mustang back in the day and it wasn't a big difference., I'd say spend your money else were specially if your considering going with a power adder.

 

[Mikepol2]

I have Ford Performance 4.09’s and love them. If you do the calculations, going from 3.73's to 4.09's in a 2018 puts the same amount of force to the road as if you added 40 ft-lbs of torque. 3rd gear really wakes up. My car had 3.73's originally. Was originally wishing for 4.30’s but now having these 4.09’s I wouldn’t swap them for 4.30’s even if it was zero cost because of the ratios of the factory 6 speed. I only use 1st if I’m starting on a hill or need to get out quick, and 6th is comfortable for cruising at 50-55 mph on flat roads. Side note - my gear installer said these were some of the highest quality gears he’s ever seen. All that being said, the 2018+ cars have different transmission ratios than the 2015-17 cars, so not sure how closely my experience would translate.

 

[Templarum]

I have Ford Performance 4.09’s and love them. If you do the calculations, going from 3.73's to 4.09's in a 2018 puts the same amount of force to the road as if you added 40 ft-lbs of torque. 3rd gear really wakes up. My car had 3.73's originally. Was originally wishing for 4.30’s but now having these 4.09’s I wouldn’t swap them for 4.30’s even if it was zero cost because of the ratios of the factory 6 speed. I only use 1st if I’m starting on a hill or need to get out quick, and 6th is comfortable for cruising at 50-55 mph on flat roads. Side note - my gear installer said these were some of the highest quality gears he’s ever seen. All that being said, the 2018+ cars have different transmission ratios than the 2015-17 cars, so not sure how closely my experience would translate.

Do you think a 6 speed automatic would experience a similar gain in torque equivalency from this swap? What if you're switching from a higher gear like 3.55 or 3.31? I'm unfamiliar with the specific equations involved with these calculations. Thanks...

 

[Mikepol2]

This video should help...

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