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Discussion Starter #1 (Edited)
Hey guys so I finally did my gear swap today at Steeda Autosports in Pompano Beach Florida and instead of just posting a massive paragraph of my experience, I decided to do a Frequently Asked Questions review to this swap. I pulled some of the most asked questions regarding gears and gave my own "opinion and experience" based answers on the transition from stock 2.73 gears to 3.73, the most popular gear swap for our cars. Its a bit lengthy in total, but I hope this is helpful to anyone in the South/Mid Florida area on the fence about doing the swap @ Steeda in Pompano Beach FL, and to the community in general, how the transition to 2.73 to 3.73 is for me on a manual transmission cyclone. :)

Q: How much did Steeda charge you? [TJ if you can chime in on this one]
A: Initial quote was $550 for the swap on a 2014 Mustang V6 Manual transmission at 6200 miles on the odometer when I brought it in. Before the swap, I bought my SCT X4 from MPT and requested in the form to load on the 3.73 ratio on my 3 custom tunes in order to have everything 'plug and play' on the day I arrived to Steeda for the swap. No point in asking for a 2.73 ratio when I already knew I was doing the swap. I first contacted Steeda via live chat on their website and spoke to Rod, very friendly and knowledgeable. I put down a $150 deposit to reserve the shop time a week before the install and prepared the order. A week later (Today/Friday) When I arrived and the pricing was discussed, Don gave me a discount for a differential housing part that I requested to be added on but it was not necessary to the install, so my cost came out to $650 out the door, but without the differential housing kit, $550 for a 3.73 swap is pretty accurate, maybe even lower if Steeda has a sort of Mustang Evolution discount if they can be sent more business from this referral and the 4 other people in my area ready to bite the bullet on this one. Keep in mind my mustang is a 14 with 6200 miles, if you have a mustang with some more mileage, parts could change and the price might creep up a little bit. On the invoice, the most expensive segment was the labor, which came out to $350 for a standard 4 hours of time. So although you might pay a little north of $550 if you have a high mileage cyclone or older SN197, the labor should be the same, depending on what your car has or might need for a rebuild kit.

Q: What was the turnaround time?

A: I got into the shop at 1:15pm and had my car swapped to 3.73 ready and finished at 4:40pm so almost 4 hours; 4 hours was my quoted time for labor and they managed to shrink it down to 3 hours 25 minutes. The cost for labor is negligible, as long as it was done right, I wouldn't whine about 35 minutes of labor overtime paid, plus the discount I got on the housing, any 'attitude' on invoice labor would be ridiculous.

Q: How was the install (waiting) experience overall?
A: Awesome, the guys at Steeda treat you like family; a very chill environment and a TON of mustang specific magazines to sift through if your not the mobile phone type of person. In the 3 hours I spent there, I learned a lot from the employees about mustangs in general and and and a lot of interesting Stang's pulled in. There was a nice 15 gt being worked on which turned out to be one of the manager's own cars testing out a tune. The consensus around the office was that the 15 mustang GT's are a ***** to work on but Steeda was trying to remain competitive against BAMA and MPT to get a stable tune on the 15 models. Some eye candy rolled in as well - a 2003 cobra came in, and I believe one of the employees had a nice 2008 GT, very impressive. Overall, the wait to get the gears done was 'cozy' great vibe there and easy to kill 3-4 hours waiting on the install to finish. I was able to hang out in the sales area and talked to a few employees who know a lot about our cars (obviously) and I can say I was confident they could handle the gear swap with no problem.

Q: What ratio did you get? What did you have before?
A: I had the stock 2.73 ratio and switched to the 3.73 ratio as per Don @ Steeda's recommendation. I asked him if on a manual transmission that might be a little too short a ratio for a daily driver, but he said its the most popular swap they do and even for a manual, he recommended 3.73. 1st gear is still useable even on daily driving but you will shift a lot more. You have the option of starting in either 1st or 2nd gear, with 2nd gear being a smooth transition from a stop and 1st begin about a 1-2 second pull to redline depending on other mods.

Q: Was a tune required?
A: Yes, I brought in my SCT X4 tuner, with 3 custom tunes from MPT Performance preloaded with the 3.73 axle ratio on all 3 tunes. Steeda specifically mentions to bring your tuner the day of the install. I wouldn't know what they would say if you didn't have your tuner with you, but I would recommend getting the tuner first as a mod install, then gears or CAI at your discretion and budget. My logic is that if you have the shop doing the gear swap and you have a tuner with custom tunes on it, you are pre quoted the labor for the mechanic to ensure the tune works correctly with the custom tunes at the time of the install. It would suck to have the gears installed first without a tune, then tune the car and realize you have a problem. Steeda also offers their own tunes so kill 2 birds with 1 stone and have the tuner preloaded with your 3.73 custom tune in the file before hand when you arrive at the shop so if any diagnosis needs to be done, its done by someone who knows what could be going on.

Q: What is your reaction starting up on 3.73's with a standard transmission?
A: Well you can actually start out in second gear now which is cool. Since your not used to the ratio, its very easy to over rev and begin chirping the tires hard even with traction fully on in 1st gear. 1st gear to me now acts as either a 'gun it from a stop' gear or '0-60 time' gear. For daily driving, 2nd gear now becomes your old first gear but if you are experienced with your MT82 transmission, you can still start off relatively smooth in 1st but its a quick shift to 2nd gear under normal circumstances. As far as cruising around and moderating gears based on whats going on while driving in traffic, I would say when I had the 2.73's and I wanted to rev match, if I was going 20MPH for example, I knew I could be in 3rd gear and the engine would be around 1.2-1.5k RPM's. So in my head I knew more or less the first number of the MPH I am going, just add a number up for that gear (10 mph, 2nd gear for smoothness, 20mph, 3rd gear, etc...) BUT with the 3.73's, its adding another number to make a smooth transition for daily driving. So if I was now going 10mph, I would go to 3rd gear for a smooth transition at 1.5k RPM's, 20mph would be 4th gear, and so on. What you find is that the wonderful MPG you have been getting ends once you go passed 40MPH because now your in the highest, 6th gear at 1.5k RPM's...but we don't get 3.73 for MPG :) Its for the "holy crap, the car is about to jump to 1987 in a matter of seconds" feeling. And man does it let you know it FAST. An interesting thing I noticed is that with the Steeda CAI I had on the car, the car moved so damn fast from a stop that combined with the sound of the CAI in front of you, it might convince you the car is running a turbo. Definitely the first 3 mods every v6 owner should get is a tune, CAI, and gears. Those 3 are just incredibly on how much it changes your car. I was skeptical on how much the car would actually be different, but believe me, you really feel like it has the torque of a grand sport. I know because Ive driven a 2014 grand sport plenty of times and that 'knock-back' feeling is very close to that sensation..Especially when the front end begins to rise at 5k RPM at 1st gear 0.0

Q: How has your Miles Per Gallon changed?
A: For the break in period I am keeping it under 60 MPH...but in 6th gear, 60 MPH on the highway, your getting a solid 2k RPM engine speed which really will make those MPG's dump. If your in a manual, you can play with the clutch on hills to make the most out of it if your really stingy, but your going to lose a lot of MPG on the highway or going a long distance over 50 MPH...no matter what...You can go up to 70 or 80 cruising which is around 2.5/2.6 RPM engine speed, but your just dumping fuel (93 octane at that, not cheap) to get somewhere 5 minutes sooner if this is just commuting miles.

Q: Is there a break-in period after the swap?
A: Surprisingly, the only mention of a break in was, quote - "Take is easy for the first 200 miles"...After reading extensively on other forums, and having to do the drive back from Pompano to Miami, a 1 hour drive, I knew a little bit about heat cycling the gears and for the first time I can ever say, I was so happy to hit rush-hour traffic (lol). Cruising to no more than 60 MPH at 6th gear let the wear pattern for 6th set in for the first 20 miles. When I hit my first traffic spike, I fiddled between keeping the car engaged in both 1st and 2nd gear for about 15 minutes. Here and there I would spurr to 4k RPM's and clutch in to cool off what I could in the rear differentials until traffic moved again. In my hour road trip back to Miami, I was able to use all gears from 1 through 6 and did not notice any gear whine or negligible effects from breaking in. When I arrived home, I let the car sit in the shade for an hour and drove again at cruising RPM shifting through all the gears to develop a similar pattern on the highway trip. On my invoice the gear fluid used was Ford's Motorcraft brand but at 500 miles I will be switching to Royal Purple to change out any metallic that might have formed in the break-in period. I know for some people this 'break in' idea of gears might not be necessary, but better safe than sorry and traffic for once in my life worked to my favor at rush-hour 5:00pm Miami time on a Friday :)

Q: You mentioned major chriping in 1st gear, any suggestions for an easy pull out?
A: After experience, I would say once the swap is complete, pull out of the shop in 2nd gear to a straight-line road and gun it. This will give you a fair estimate of the differences between your stock ratios versus your new setup. As mentioned before, you can pull out in 1st but expect to shift quickly to 2nd, it might be best to start in 2nd since the gear will actually push you to roll before you are close to stalling. As far as chirping and making noise at stops, start to appreciate you have 305 to the crank; gentle on the throttle and you can casually shift through the gears. Otherwise I would say start in 2nd if your nervous about drawing attention and just shift when you hit 2k RPM to the next gear.

Q: Is the reverse gear affected by the swap?
A: Yes but barely noticeable. Think about the same revs you used to do in 2.73's while reversing to keep the car from stalling and apply that to a 2nd gear on the old 2.73's; its difficult to make the car stall as the new gears will keep the car rolling in either direction - reverse feels almost the same as stock but there is no more need to blip throttle to keep the car from staling while you are pulling out.

Q: If I have an Automatic, should I get 3.73 or 4.10 gears?
A: I Cant speak for an automatic cyclone but if the gear transition is the same on the manuals (I heard that the automatic transmission changes at the most 'efficient' RPM) I would say 3.73 will be an excellent choice. 4.10 might be too aggressive for your daily driver but that is my speculation. I would read up on other threads about automatics and the 4.10 gear ratio before deciding on this swap if its your daily driver, but a 3.73 would be a great option.

Q: Will a 3.73 swap void my warranty? [Forum, please clarify/verify for accuracy]
A: The short answer is maybe...consider the fact that a licensed Ford dealership will only swap a gear up to a ratio of 3.33 to retain and honor the factory warranty on the 'differential'. By swapping to a 3.73 gear on the differential, your gear ratio will not be covered by Ford Warranty Claims if it had to call upon a contract warranty for repairs. But you already knew this didn't you... The problem and grey area is Steeda and affiliation Steeda has within Ford. This topic of warranty 'claim' denials and aftermarket parts is discussed ad-nauseum within this forum and its quirks and policy details are too lengthy to go into this topic within this thread. Short answer for that - A denial is based per dealership and records kept of your vehicle and its type of uses along with your insurance profile. However, when I asked Don, my lead service adviser at Steeda before beginning the install, he confirmed that Steeda will stand by their installation should the unexpected occur that is related to the swap itself (not talking about destroying your rear end on on a quarter mile because you just so happened to have a Steeda shop installed 3.73 gear ratio on your car at the 'time of loss')... IF something went wrong with the install and Steeda was at fault due to installation based on faulty/defective parts provided by the shop who installed them, Don assured me they would stand by their service and correct what might have gone wrong. Now although i don't doubt this, and the grey area between Roush, Steeda, and other licensed ford 3rd party manufactures for warranty is hazy, IF you have a differential problem that was solely based on the gear swap, Steeda would stand by their installation, assuming it was within a reasonable time to notice problems, if any, upon installation completion. BUT if you had a gear problem that ended up destroying the driveshaft or other factory OEM part due to an aftermarket installation not recognized as 'COVERED' under your power-train warranty certificate, then it gets very hazy and you should read about the magnusson-moss act. Of course this is the, 'what-if-warranty' dilemma we all see and at the end of the day, is up to who can cover the claim and blame fault; beyond the scope of this thread.

Q: Is a gear swap on stock 2.73 to 3.73 worth it?
A: If your on the fence about doing a swap because it might seem too expensive from other quoted shops, (I have seen threads about a $1000 quote at Ford to swap, with no warranty) I would say Bite the Bullet and Do It (but do it right). There are a plethora of threads on the performance increase and bang-for-the-buck mods for our cyclones and this mod is, in my opinion the #1 bang for the buck next to turbo/prochaging based on $$$ to feel of difference. However, I do understand that you have to do it right, because it can be expensive to do a swap, regret it, and then go back to another swap (Labor costs add up quick for correcting a buyer's remorse mistake).

My best advice before you think of purchasing a short gear swap
: See if you have a friend (or someone here on mustangevolution in your area) that can show you what its like driving a 3.73 ratio before you take the plunge. It can be our cyclone engines or even an older 'new edge' 2002 gt; what you want to pay attention to (Manual transmission specifically) is your shifting pattern and how much you want to deal with on a daily driver..and I stress DAILY driver, this mean limiting highway driving - road trips are a financial no-no with this gear ratio due to fuel costs, and that 24/7 raw acceleration all the time on demand, anytime you need to go somewhere... As many people have said, it WILL wake that thing you call a V6 and it WILL put a smile on your face if you have stock ratios..but, keep in mind it can be aggressive at times and depending on your demeanor, this is a mod that once put on, can be hard to justify paying an additional $550 to swap out to a lower ratio if you think its too much. Overall I put my confidence with Steeda and so far at 130 miles in on the swap, will say that I am very satisfied with the professionalism and quality of work they did on the swap. besides...IF you chose to do a swap with another shop because maybe they are quoting you a bit less, its the confidence that the shop that is doing this major change is STEEDA...not 'Joe's Differential's LLC' :D

Hope you guys enjoyed this little review, if you have any other questions or live in the South Florida, Miami area, shoot me a PM and ill be glad to meet up with you and show you how the difference is. Got a bunch of ppl in Miami thinking about this so I guess ill be the guinea pig and say - DO IT!

Steeda Autosports via Gmaps - https://www.google.com/maps/place/Steeda+Autosports,+Inc/@26.245091,-80.153661,17z/data=!3m1!4b1!4m2!3m1!1s0x0000000000000000:0x3f7fbda289c92917
 

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This is my next big mod after I get the Koni yellows/steeda sport springs installed. I will be going with 3.55s as I do a bunch of highway driving. I figure I'll get close to the same fun as the 3.73s, but will save a few cents a mile on the highway. Haha I also have an auto, which they say runs at slightly lower rpms due to the transmission gearing.
 

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Discussion Starter #3 (Edited)
This is my next big mod after I get the Koni yellows/steeda sport springs installed. I will be going with 3.55s as I do a bunch of highway driving. I figure I'll get close to the same fun as the 3.73s, but will save a few cents a mile on the highway. Haha I also have an auto, which they say runs at slightly lower rpms due to the transmission gearing.
Yeah if you see a lot of Highway driving on your weekly commute, I would say 3.55 would be ideal. There is also the bonus that if you have a longer gear and you end up going F/I down the line, that extra power needs more time to be kept in the power band. I think for automatics 3.73 and 4.10 are the cats meow if your still N/A but that is 100% performance. For a Daily driver with highway, if your running those short gears, better get used to having camry's and corollas pass you going 70 at ease on the highway because if you want to save money, its 55 MPH for you (lol) just the thought of that analogy makes me cringe

Its kind of funny in a way but for the first time, I actually consider a really short gear to be paired with an automatic transmission. If I was not confident enough in my shifting, doing redline at first gear with the 3.73's on manual with stock drivetrain makes you feel like the rear axle or something else is going to break, its that much of a bite if you have the right tires to get the hook
 

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Getting mine done on Monday and I have a automatic....this only adds to the excitement !! So my review will be a automatic review! Bought my tuner loaded for the .373 gears. So I will install it when I drop it off!! Can't wait and how old am I??? Lol 56 and this stuff still revs me!! :)


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Getting mine done on Monday and I have a automatic....this only adds to the excitement !! So my review will be a automatic review! Bought my tuner loaded for the .373 gears. So I will install it when I drop it off!! Can't wait and how old am I??? Lol 56 and this stuff still revs me!! :)


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Nice! You should include your review here so we can get an automatic and manual review. Possibly keep it in the same format and we can have it stickied since this topic seems to come up daily. If you can, find out what the rpms are at 65 and 75 for a comparison to the manual.
 

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Thanks for this info. I might be considering doing this by end of year or beginning of next. I would just have a bit longer drive of 3 hours to get home from Steeda. Great write up though!!!!
 

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I will post it here....I hope I went with the right gear. I hope I didn't go to BIG! I was going to go .355, but AM said .373!


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Discussion Starter #8
Just got a reply ba k from TJ at steeda, he is going to see if they can offer a discount for mustang evolution owners that will do the swap at the pompano location, fingers crossed!

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Discussion Starter #9
Nice! You should include your review here so we can get an automatic and manual review. Possibly keep it in the same format and we can have it stickied since this topic seems to come up daily. If you can, find out what the rpms are at 65 and 75 for a comparison to the manual.
A sticky would be great and we can add anyone else who has questions about the swap :D
 

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Great write up much appreciated
I went with 4.10s a while back cause i wasnt worried about top speed but i love whipping the back end and drifting it does cut my power curve a bit short, and when i put twin turbos on i might go down to a 3.55 instead, first is still usefull but not for long
My gas mileage went from 21 to 17 so thats a con

But overall i love the new gears its insanely faster and as for soundling like its turboed i put on a airaid cai, 73mm bbk throttle body, and then the gears and it does sound like a smaller turbo and gets so much air it kind of hissed from the breather while accelerating, i want to get a solid 0-60 time to compare but that might be a while, but it destroys my buddies 2002 m3 even keeps up with and can beat my bosses 2004ish era roush stage 3, eats bmw z4's alive

Shifting has become slightly irritating as i have to so often but it being so easy to spin the tires and step the back end out i can deal with it at 80mph in 6th gear i believe in at about 3000rpm ill double check but ny car also pulls itself up to speed in lower gears as if its an automatic, nice feature in socal traffic haha, hope this helps a bit for comparison,

I might switch to 3.73 just for a bit an try it out so i can refrence the pros and cons of both, it seems thats pretty rare, either you get 3.73 or 4.10's

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Correct me if I'm wrong but wouldn't going to 4.10 gears pretty much dictate the 1 pc driveshaft?
That is to say, the driveshaft would be turning at an RPM equivalent to a much higher speed than the governed speed of approx. 115 mph.
The way I see it is, comparing it to 3.31 gears, the 4.10 gears require the driveshaft to turn 4.10 divided by 3.31= 1.24 times faster.
1.24 x 115 mph = an equivalent speed of about 142 mph.
 

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Great write up. I live just north of Pompano and have considered driving down to have them do my installs like gears and lowering springs. Plus after speaking to TJ about purchasing a tune from Steeda, maybe I can get a good package deal.
 

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Discussion Starter #13
Correct me if I'm wrong but wouldn't going to 4.10 gears pretty much dictate the 1 pc driveshaft?
That is to say, the driveshaft would be turning at an RPM equivalent to a much higher speed than the governed speed of approx. 115 mph.
The way I see it is, comparing it to 3.31 gears, the 4.10 gears require the driveshaft to turn 4.10 divided by 3.31= 1.24 times faster.
1.24 x 115 mph = an equivalent speed of about 142 mph.
I believe I heard about this somewhere, especially once your really running the engine hard, a failure at 90 mph on the 2 piece seems plausible based on rotational mass but I am not mathematically close to confirming this, maybe voltwings would know.

Great write up. I live just north of Pompano and have considered driving down to have them do my installs like gears and lowering springs. Plus after speaking to TJ about purchasing a tune from Steeda, maybe I can get a good package deal.
Still no word from TJ but it is the weekend, if Steeda will allow for some time of discount (maybe on the actual FRPP gears) then they could bring the price down, labor is labor that is locked in I believe, thanks :)
 

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I believe I heard about this somewhere, especially once your really running the engine hard, a failure at 90 mph on the 2 piece seems plausible based on rotational mass but I am not mathematically close to confirming this, maybe voltwings would know.



Still no word from TJ but it is the weekend, if Steeda will allow for some time of discount (maybe on the actual FRPP gears) then they could bring the price down, labor is labor that is locked in I believe, thanks :)
Yes ...I was hoping he would comment on it.
It seems pretty straight forward to me but then again sometimes I miss the obvious.
 

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We are on it ... I spoke to my sales manager today & we are running the numbers to see what we can do ... we are working diligently behind the scenes!
Chris ... yes, we can work on something if you come down! Send me your info again (my inbox gets full quickly & I have to remove old messages) & I will send to David to run the pricing!

I will inquire about the gears & the driveshaft too ... see what our experts say.

I will let you know as soon as I hear from my sales manager!

Best Regards,

TJ
 

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Yes ...I was hoping he would comment on it.
It seems pretty straight forward to me but then again sometimes I miss the obvious.
I do believe you are correct although given the rpm rev limiter i do not believe it is an issue, also i have 4.10's and after the break in period i definitely put them through their paces and they still hold strong just like the drive shaft

You might be correct about the effects but then again i do believe the ratio of 4.10 means it takes 4.10 turns before the pinion to one wheel revolution? I may be incorrect, but this is what i read before, if that is true then hypothetically the change in ratio wouldnt actually effect the driveshaft as you believe it might, given that it will just be a higher rpm at a given speed but the tachometer never required tuning so the rpm's are correct

In short and less confusing rambling, you limit your overall speed due to the rev limiter but aquire faster acceleration, so i can speed up fast but cant max out say like a 3.55 or 3.31 given this hypothesis id say there isnt such a fear in driveshaft failure, ive gotten up to 120 before because i had the same theory, but the invincible mustang powers on

Also not sure about this but even at a higher speed i believe the load is still far to low to threaten the integrity of the driveshaft, might be wrong, hopefully not but my max power was only 260 hp with all mods, so i cant really justify buying a 1 piece, however wonderful it might be to have one

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I do believe you are correct although given the rpm rev limiter i do not believe it is an issue, also i have 4.10's and after the break in period i definitely put them through their paces and they still hold strong just like the drive shaft

You might be correct about the effects but then again i do believe the ratio of 4.10 means it takes 4.10 turns before the pinion to one wheel revolution? I may be incorrect, but this is what i read before, if that is true then hypothetically the change in ratio wouldnt actually effect the driveshaft as you believe it might, given that it will just be a higher rpm at a given speed but the tachometer never required tuning so the rpm's are correct

In short and less confusing rambling, you limit your overall speed due to the rev limiter but aquire faster acceleration, so i can speed up fast but cant max out say like a 3.55 or 3.31 given this hypothesis id say there isnt such a fear in driveshaft failure, ive gotten up to 120 before because i had the same theory, but the invincible mustang powers on

Also not sure about this but even at a higher speed i believe the load is still far to low to threaten the integrity of the driveshaft, might be wrong, hopefully not but my max power was only 260 hp with all mods, so i cant really justify buying a 1 piece, however wonderful it might be to have one

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What "RPM Rev Limiter" are you referring to? I have to assume the speed limiter is based on the actual MPH. And at a given MPH the driveshaft turns at a specific RPM based on tire diameter and rear end gear ratio. It is true that when the driveshaft turns 4.1 revolutions the wheels turn 1 rev. So the driveshaft is turning about 24% faster at the same MPH than it would with the 3.31 gears. (picked the 3.31 gears since that is what Fords design limited to.)

I think the driveshaft issue is more of an RPM /Harmonics issue.
Also, I would think that the governed/limited speed is based on the actual speed and not on engine revs. And I am assuming that it's being obtained from the transmission.
So with the 4.1 gears, without a speedometer correction, it would show close to 115 MPH when in fact you're doing 93 MPH due to the 24% increase in revs of the drive shaft.
With the speedometer correction it would show the 93 MPH but the driveshaft speed is the same as if it was going 115 MPH.(93 X 1.24)
So if the ECU limits the speed of the car based on the corrected speed, it would allow the speedometer to reach 115 MPH which means the driveshaft would be turning 1.24 times faster or the same as if the car's speed was about 143 MPH.
Of course I'm assuming the driveshaft failure is due to the driveshaft reaching a critical speed and the car speed is only related by gearing and tire diameter.
 

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Discussion Starter #18
What "RPM Rev Limiter" are you referring to? I have to assume the speed limiter is based on the actual MPH. And at a given MPH the driveshaft turns at a specific RPM based on tire diameter and rear end gear ratio. It is true that when the driveshaft turns 4.1 revolutions the wheels turn 1 rev. So the driveshaft is turning about 24% faster at the same MPH than it would with the 3.31 gears. (picked the 3.31 gears since that is what Fords design limited to.)

I think the driveshaft issue is more of an RPM /Harmonics issue.
Also, I would think that the governed/limited speed is based on the actual speed and not on engine revs. And I am assuming that it's being obtained from the transmission.
So with the 4.1 gears, without a speedometer correction, it would show close to 115 MPH when in fact you're doing 93 MPH due to the 24% increase in revs of the drive shaft.
With the speedometer correction it would show the 93 MPH but the driveshaft speed is the same as if it was going 115 MPH.(93 X 1.24)
So if the ECU limits the speed of the car based on the corrected speed, it would allow the speedometer to reach 115 MPH which means the driveshaft would be turning 1.24 times faster or the same as if the car's speed was about 143 MPH.
Of course I'm assuming the driveshaft failure is due to the driveshaft reaching a critical speed and the car speed is only related by gearing and tire diameter.
Looks like you could be bringing to light a critical upgrade if someone wants to change to a very high gear, now I am afraid of going 93MPH lol
 

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Looks like you could be bringing to light a critical upgrade if someone wants to change to a very high gear, now I am afraid of going 93MPH lol
That was my exact point...assuming of course that I am correct.
 

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To keep it simple it is my understanding that the V6 has a MPH limiter. That said there is only one thing that stays consistent, and that is the tire diameter. The tire will rotate the same number of times over a given distance no matter the gear ratio! So the engine trans, and driveshaft must rotate faster. I you plan on driving faster than 90 mph, you should install an after market driveshaft ASAP. I have seen these DS come apart and you don't want to have it happen to you, you will be paying for a new trans. the car has both a rev limiter to protect the engine, and a mph limiter to protect the DS.
 
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