djoneill

I'd really like to put 3.31 gears in my '12 convertible but short of a tune that may or may not void the 5yr/50,000 powertrain warranty, it's not currently possible.

Does anyone know, if a SpeedCal becomes available for the MT-82 VSS sensor, will we be able to use it to correct for a non-stock ratio?

I can imagine the PCM running the engine rpm/transmission gear against output from the ABS sensors and throwing a code, but I'm hoping the car is not that smart. The 2.73s are ridiculous-- the car does 50mph in first gear.

djoneill

Update: I talked with Dallas Mustang yesterday about Speed Cals for our cars, and they are looking into it.

They realize it's a problem that you need to install a custom tune just to change the the rear axle ratio from 2.73 to 3.31.

We discussed them coming out with a kit of gears and a Speed Cal for V6s, and they're probably going to look into.

Anybody else have some thoughts on this topic?

JayyVee

Thoughts (mine, don't take offense) as requested;

I understand the desire to not 'tune the car', wanting to keep the warranty valid. I follow you there.

Pretty sure changing gears is going to void the powertrain warranty which only applies to originally installed parts or parts replaced due to undue wear and replaced by Ford under documented warranty use - the problem is the replacement part(s) themselves, (Ford gears or otherwise) you're opening the gearbox up. A tune at that point is pretty moot point I'd think.

The whole dance of 'prove that my modification caused the damage' really applies heavily to parts interchanged, especially so.. I mean think about it.. They 'know' what gearing your car was sold with when they pull it up on their computers.. Suddenly you have trouble, you take it in and they open it up (noticing it's been opened before..) and wow, gears that didn't come stock. - VOID. (Maybe the issue wouldn't have happened with proper tuning?)

Now, if you had actual gearing issues, and Ford decided it was going to change them out under warranty, and you were able to 'convince' them to put in higher gearing while warranty work being done - that would fly. Otherwise I think it's asking for more trouble than it's worth if the warranty is the golden egg here.

I think it'd be better if you want the gears changed to do it 'right' as much as it can be under warranty; get a tune for it, and enjoy it, and don't plan on going to Ford for gear issues, rather your installer.. Save the visits to Ford for warranty work for other issues unrelated to the modified powertrain. Replacing axleback mufflers, CAI's, and tunes back with original parts and original tuning and going in for warranty work around issues that 'said parts' can effect, sometimes works - gears, not so much I'm thinking. (not advised either, pretty scammy to me - I took the big boy steps to modify, I will deal with the fallout - pay to play)

End Thoughts
(sorry didn't mean to pour salt...)

Mownt

It is my understanding that if you changed gears the gears themselves and the rest of the rear end would no longer be warrantied. As far as the rest of the powertrain Ford would still have to cover it.

I asked Ford corporate about gear changes and this is the reply:

"Any alteration done to the vehicle would not in of itself affect warranty. If a mechanical issue arises on the vehicle due to the alteration then it could affect warranty. Please consult your dealer for any technical questions about the alteration. We appreciate you taking the time to write us and hope everything works out for you. Thank you for contacting Ford."