OaktownACE Posted January 24, 2015 Report Share Posted January 24, 2015 I'm debating the gear change from 3.31 to 3.73. I do mostly spirited driving on canyon roads and the highway with occasional stop light to stoplight fun. I'm more likely to go to a road track than a drag strip so I know this car doesn't really fit that profile but it's addicting in its own way. I'm just going to run the mpss and it's not a widebody. So all that said, I've read through a ton of threads and most are early after the gear change. Most of those are very positive because the car feels faster, lugs less, and requires less daft touch on the clutch from a stop. now after guys have had them for a period of time, put some miles and some hard launches how are people liking them? Has traction been an issue? Have the gears started to whine? Was it worth it or in hindsight not as big a deal as you thought when you first did it? Quote Link to comment Share on other sites More sharing options...
2007red40thGT500 Posted January 25, 2015 Report Share Posted January 25, 2015 i've had 3.73s in both cars i've owned... 4.6L and 5.4L. personally, I'd go with 3.55s in my 5.4L if Shelby hadn't spec'd 3.73s. still can't really complain too much. just make sure they are Ford Racing and not some other brand. Quote Link to comment Share on other sites More sharing options...
SlowMan Posted January 31, 2015 Report Share Posted January 31, 2015 I have 3.73 in my 800 hp SS and 3.31 in my 500 hp GT500. I personally do prefer the 3.31 and most likely one day i therefore will swap to 3.31 in my SS. I'm expecting advantages in less shifting work but unfortunately wheel spin in the lower gears will still be there due to the high hp rate. Manfred Quote Link to comment Share on other sites More sharing options...
OaktownACE Posted February 1, 2015 Author Report Share Posted February 1, 2015 I have 3.73 in my 800 hp SS and 3.31 in my 500 hp GT500. I personally do prefer the 3.31 and most likely one day i therefore will swap to 3.31 in my SS. I'm expecting advantages in less shifting work but unfortunately wheel spin in the lower gears will still be there due to the high hp rate. Manfred Are you finding you have to row through the gears too quickly with the 3.73? Is traction realistic with the 3.73? On the 662 hp GT500 I find myself never really having to leave 2nd gear around town, 3rd gear if I want to lower the rpm a bit. I find I am really feathering the clutch in first when I'm just driving normally to avoid chugging. I joke that I'm basically driving an automatic with how little shifting I do. Quote Link to comment Share on other sites More sharing options...
SlowMan Posted February 2, 2015 Report Share Posted February 2, 2015 I mean, it's a matter of personal taste. For daily use 3,73 is for me just as fine as 3,31. But now and then I also like to go sporty. And then compared to 3,31, I must shift significantly more often and quicker with 3,73. Too much and too quick in my opinion. Quote Link to comment Share on other sites More sharing options...
2007red40thGT500 Posted February 4, 2015 Report Share Posted February 4, 2015 this horse has been beaten to death in other posts online, but here's my 2 cents regarding rear gear options on an average GT500: 4.10 - don't waste your time or money 3.73 - keeps engine revs up and in the power-band more often. great for spirited driving, still good enough for highway use 3.55 - perfect for daily driver 3.31 - too tall for spirited driving, but good for gas mileage and highway cruising Quote Link to comment Share on other sites More sharing options...
Robert M Keefe Posted February 5, 2015 Report Share Posted February 5, 2015 You hit the nail on the head. +1 Quote Link to comment Share on other sites More sharing options...
SlowMan Posted February 5, 2015 Report Share Posted February 5, 2015 ... on an average GT500I totally agree with you but we are in the SS section here so I guess we are not talking about an average GT500. 3.55 - perfect for daily driverYes, I think this is a good compromise and would fit as good on a 500 hp GT500 as on a 800 hp SS. So I think 3.55 would meet the needs of OaktownACE best. He asked for feedback and I think it was worth our little discussion. Manfred Quote Link to comment Share on other sites More sharing options...
2007red40thGT500 Posted February 5, 2015 Report Share Posted February 5, 2015 i think you misunderstood that statement. by "average" i mean across the spectrum from 2007 to 2014. doesn't matter if it is a SS or other build. the transmission gear ratios are pretty close across the different year models and anything above 500HP is going to break the tires loose with any ratio. the only reason i stick with 3.73s over 3.55s is because Shelby American specified them for the 40th anniversary package (like they do for all of their GT500 builds). Quote Link to comment Share on other sites More sharing options...
OaktownACE Posted February 5, 2015 Author Report Share Posted February 5, 2015 I totally agree with you but we are in the SS section here so I guess we are not talking about an average GT500. Yes, I think this is a good compromise and would fit as good on a 500 hp GT500 as on a 800 hp SS. So I think 3.55 would meet the needs of OaktownACE best. He asked for feedback and I think it was worth our little discussion. Manfred I really do appreciate the discussion. I've read just about every post I can find online about the gears and most are posted in the first few weeks after changing them. I've found a few follow up posts and most indicate that after a drag strip day or two the gears start to whine. Most people still think the 3.73 is a very good gear for the car. Some question 3.73 with the additional hp and traction. 3.55 sounds great to me but I'm into one stop shopping as I've got some young kids and a wife who is semi tolerant of my car obsession. Shelby offers a 3.73 so that's what I'm going to do. I drive my car once or twice a week and today on my way to work I didn't have to get out of second gear. It was kind of boring and with the 3.31 I don't have the head snap I would expect from 662hp. Not to mention the high friction point on the clutch and feathering required to launch smoothly. I'm hoping the 3.73 will help some of that but I'm risk adverse so the unknown on install re: whine or other problems, makes me hesitate. Quote Link to comment Share on other sites More sharing options...
2007red40thGT500 Posted February 5, 2015 Report Share Posted February 5, 2015 whine is usually due to offbrand gears or a poor installation, not gear ratio. and yes, the 3.73s will force you to shift since you'll only get to 45mph in first before hitting the redline. good luck. Quote Link to comment Share on other sites More sharing options...
Jimmy Sak Posted February 5, 2015 Report Share Posted February 5, 2015 whine is usually due to offbrand gears or a poor installation, not gear ratio. and yes, the 3.73s will force you to shift since you'll only get to 45mph in first before hitting the redline. good luck. Or the gears not being properly broken in....that was expressed when I picked up my SS. Quote Link to comment Share on other sites More sharing options...
OaktownACE Posted April 14, 2015 Author Report Share Posted April 14, 2015 Or the gears not being properly broken in....that was expressed when I picked up my SS. Anybody drag the car and then not have whine? I've been reading and everyone who has hard launched their car with the 3.73s has gotten a whine after. I will qualify that by saying none were Super Snakes, but I would think with the additional hp it would be a more prevalent problem. Quote Link to comment Share on other sites More sharing options...
shel-b001 Posted April 14, 2015 Report Share Posted April 14, 2015 Anybody drag the car and then not have whine? I've been reading and everyone who has hard launched their car with the 3.73s has gotten a whine after. I will qualify that by saying none were Super Snakes, but I would think with the additional hp it would be a more prevalent problem. It shouldn`t be if the gears are properly installed . the whine comes from to much backlash clearance in the gears doesn`t matter if they are 4:10' s 3:55 , 3:31 etc. Quote Link to comment Share on other sites More sharing options...
mrl859 Posted April 14, 2015 Report Share Posted April 14, 2015 I recently purchased a 2013 with 3.73 gears. I never had the benefit of driving with the 3.31s, so I can't comment on them or the difference. That being said, the frequency of shifting feels very similar to my 2012 with SVTPP/3.73 factory gears. It's been too long/too many cars since I had my 2010 with 3.55 gears so I don't remember what that was like. My gears whine quite a bit at about 40 mph plus on light acceleration, but I believe they were set up wrong and I'm working on that. My 2012 factory 3.73s were silent. Quote Link to comment Share on other sites More sharing options...
poppagroove Posted May 26, 2015 Report Share Posted May 26, 2015 The hard launch has nothing to do with a whine...the whine comes ( if it comes ) from a poor instal ie..not shimming properly ect...Just get somebody who knows how to set up a rear end and then enjoy....I run a 3.73 in mine and I love it for all around driving.... Quote Link to comment Share on other sites More sharing options...
Robert M Posted May 26, 2015 Report Share Posted May 26, 2015 (edited) I like the 3.73's in my 725, they seem to help an "already heavy" GT500 get going with less effort. Less clutch manipulating is also a plus at lower rpm's. If the "right pedal" is pressed a little harder, my 325/30's will break loose fairly quick with the 3.73's. I do agree that a 3.55 gear would be a nicer all around gear as the hp and torque are increased, but these cars are heavy and getting the weight moving with the 3.73's seems to work well. R Edited May 26, 2015 by Robert M Quote Link to comment Share on other sites More sharing options...
Rod Simas Posted May 26, 2015 Report Share Posted May 26, 2015 I would have to say those stock 3.33 our just to high for me even thou when I raced my 67 Fairlane with 5.17 I was going through the lights at 7200 rpm and a 11.56 et 124 mph, but that was then. By the way I did my own differential setups and they don't whine with proper installation. I now have a 2014 GT 500 SuperSnake with 850 hp and I don't even use 6th gear I have to be going over 70 mph and that's with the new 3.73 which are perfect. We don't like to go to fast out here it seems the CHP don't seem to laugh about it anymore. I think I'm going to have to agree with 2007red40thGT500 even if his post is over a page long. Quote Link to comment Share on other sites More sharing options...
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