RaceRed5.0
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What do I need because I know the 3.15 differential does not work with the 3.55 gears is that all I need to switch out or is there more? Thanks!
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You'll also need an install kit which includes a crush sleeve for the pinion and a shim kit..., AND you'll have to pay someone to install all the parts.So all I need is for my auto is...
Differential
https://www.americanmuscle.com/frpp-34spline-88-irs-diff-2015gt.html
Gears
https://www.americanmuscle.com/frpp-355-gears-2015.html
^ This. Plus whenever I've had gears installed in other cars I've had some amount of gear whine. There is even a market to sell your used take off complete differential so that puts it way ahead of getting them installed.You'll also need an install kit which includes a crush sleeve for the pinion and a shim kit..., AND you'll have to pay someone to install all the parts.
After it's all said and done, you'll be at or near the price of the complete differential that you can simply buy (complete) from mother FORD.
You can install the complete diff yourself.
Wait, so I can’t change my 3.73 gears to 3.31? I need a whole new pumpkin?It's the housing that's different.
3.31, 3.55, 3.73, 3.91, 4.09 ratio gears will not fit the 3.15 carrier (Housing)
The actual differential (inside the housing), are all compatible for the Super 8.8 Mustang IRS rear end (34 spline)
It's the housing that's different.
3.31, 3.55, 3.73, 3.91, 4.09 ratio gears will not fit the 3.15 carrier (Housing)
The actual differential (inside the housing), are all compatible for the Super 8.8 Mustang IRS rear end (34 spline)
The way I read it is you can't change 3.73s to 3.15s but you should be good for all the rest in the list.Wait, so I can’t change my 3.73 gears to 3.31? I need a whole new pumpkin?
I was very close to making the switch about a year ago and never did anything. What parts did you get? Also, how much did your installer charge you?Well I went ahead and changed the diff and at first glance it doesn't seem to be worth it, I am not regretting it though yes I do notice a difference. Can't really say there is difference between the 0 to 60 times of course traction is still an issue maybe more so now. I do notice a difference from a 20 to 30 roll than I did from my 3.15's having the power there when I step on it.
I went to a place called Hillbank Motorsports by me here in Cali they charged me $300 for work. I ordered the entire Differential and they had to replace the manual flange that comes with it and put an auto one in, I could of bought the differential from AM or CJ Pony but it wouldn't be much of a difference because I would still have had to bought the flange they charged me about $940 for the diff so in all just over $1,300.I was very close to making the switch about a year ago and never did anything. What parts did you get? Also, how much did your installer charge you?
I thought there was a need to flash the BCM to update for the gearing, did you use the Whipple flare tool?
Thanks in advance!
This isn't completely accurate. If you look at any ad for Ford performance gears or differentials for the 2015-up IRS, they all mention the factory 3.15 geared differential is not compatible with the 3.31-numerically higher gears, and you must change the differential when replacing the 3.15 gears, however I haven't seen any of them say anything about the housing.It's the housing, (i.e. carrier/pumpkin) that's different.
3.31, 3.55, 3.73, 3.91, 4.09 ratio gears will not fit the 3.15 carrier (housing)
The 3.15 carrier is different from all the rest.
The actual differentials (-inside the pumpkin, the part that the ring gear bolts to), whether it be (Torsen, Traction lock, limited-slip, Open) are all compatible for ALL the 2015-up Super 8.8 Mustang IRS rear ends (34 spline).