2025 Mustang GT Gear Install

[Mikepol2]

Not so fast, kemo sabe!

Lol. Wonder how many folks on this thread have any idea what that means except us old guys

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[roket]

any shop should be able to do a ring gear and pinion easily. keep in mind you will need to go into the BCM with FORScan and tell it the new gear ratio in order for your speedometer to be accurate.
everything i said above is wrong

turns out, doing a ring gear and pinion is surprisingly difficult and involved, with some shops not even offering that service. i also didnt realize that the gear ratio thing was more than the BCM.

i definitely feel the lack of power down low as well, but thats just the behavior of the Coyote. peak torque at 4900 and peak power at 7250 (though the autos can go the full 7500, and might pick up a little more thanks to it)

 

[robvas]

any shop should be able to do a ring gear and pinion easily.

Tough to find a shop that will do one.

 

[young at heart]

Lol. Wonder how many folks on this thread have any idea what that means except us old guys

There was some fine entertainment back in those days.

And free, save the small expense of a set of rabbit ears or a cheap antenna in some cases.

 

[Mikepol2]

any shop should be able to do a ring gear and pinion easily. keep in mind you will need to go into the BCM with FORScan and tell it the new gear ratio in order for your speedometer to be accurate. i definitely feel the lack of power down low as well, but thats just the behavior of the Coyote. peak torque at 4900 and peak power at 7250 (though the autos can go the full 7500, and might pick up a little more thanks to it)

Not that easy my friend. As mentioned in my earlier post - it's a lot of labor. Removed the diff myself for my gear guy and it was an 8 hour remove-and-install job, plus the gear labor. I called a number of shops but the two dealers I called didn't want to touch it.

And also as mentioned, FORSCAN alone doesn't work, as too many 2019+ owners have painfully found out.

 

[roket]

Not that easy my friend. As mentioned in my earlier post - it's a lot of labor. Removed the diff myself for my gear guy and it was an 8 hour remove-and-install job, plus the gear labor. I called a number of shops but the two dealers I called didn't want to touch it.

And also as mentioned, FORSCAN alone doesn't work, as too many 2019+ owners have painfully found out.

ah, i knew it wasnt quite easy for the average person, but i didnt realize just how much of an in-depth process it is. taking a look at the workshop manual, there's all sorts of other stuff i didnt even know about, like backlash and spacers, and all that. surprising that two dealers said no, even knowing this new information

 

[Deleted member 63380]

I hear you can't go higher number gears on a 3.15 because the won't fit the ring. No idea what this ring thing is, but I hear Ford has a 3.73 differential available. I'd like to go bigger, but 3.73 is probably all I'll need in my 700a, especially after, if ever, I get a ProCharger.

 

[roket]

after doing some reading and some information from @Mikepol2, OP, you may not be able to change your diff ratio until the Mustang ProCal kits come out at the soonest. it looks like it may be the BCM, ABS, and PCM that all need the ratio to do their things. BCM to do speedometer calculations, possibly ABS to determine how to react with anti-lock brakes and traction control, and possibly PCM to do auto rev matching (even when not used). do note that this is all based on S550 information, so it could be wrong.

honestly, just wait for the ProCal kits to come out. they have historically allowed you to change the diff ratio, and i dont see a reason why it would be any different this time around

 

[GWink]

Any Ford Dealer or reputable shop can do a gear swap. In my 2006 GT when I swapped in the Tremec Magnum XL 6 spd. I had 4.10's put in the rear with an Eaton posi and she is great. Go 3.73 or 4.10's would be my recommendation. 4.10's will really wake it up.

How much freeway driving do you do? 4.10’s will be higher on the rev range……..there are many places near us where we can easily cruise at 85 mph (80 speed limit) and that would keep me with no deeper that the 3.73’s gear set…..JMHO…..

 

[Paul's stable]

How much freeway driving do you do? 4.10’s will be higher on the rev range……..there are many places near us where we can easily cruise at 85 mph (80 speed limit) and that would keep me with no deeper that the 3.73’s gear set…..JMHO…..

With the gears in the 6 spd 6 gear is an overdrive 1 to 1 is achieved in 5th gear so it's not really that bad on the highway. My GT has 4.10's my Dark Horse has 3.73 and both are fine on the hwy. But that's just this old man's opinion.

 

[Johnny_Casino]

How much freeway driving do you do? 4.10’s will be higher on the rev range……..there are many places near us where we can easily cruise at 85 mph (80 speed limit) and that would keep me with no deeper that the 3.73’s gear set…..JMHO…..

I work from home and rarely, if ever get on the highway.

 

[Johnny_Casino]

I appreciate all the helpful replies everyone. Sounds like I'm just going to forego the gears. Maybe concentrate on wheels, suspension, etc... on this one. I don't race on the track or the street, so not really interested in 1/4 mile times any longer. Just wanted some more grunt down low.

Perhaps I'll leave those types of mods to the fox. Just need to drive that one more often.

 

[RLE55]

Lol. Wonder how many folks on this thread have any idea what that means except us old guys

Who you calling old... Gonna hijack this thread for a moment....
Trip to the past... Buck Rogers? Roy & Dale? Hopalong?

 

[IFFV68]

Agree. Had 4.10's in my former SC Roush Mustang, found them to be too much, pretty much had no 1st gear..dropped to 3.73 and that was much better, would still hit rev limiter, just not as often...........FWIW, car had been tuned to 390 RWHP

With the 4:10’s you can pass everything but a Gas Station !

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