Used Gears

[Badboyz1620]

Hi ever one, im new to the mustang game so i must ask. My buddy is giving me his 3.73 for free. It has 20000 miles on it and im contemplating if i should put it on my car. I have a 2013 v6 with 7000 miles. Advice is appriciated i have search and it has been done. I was told that it could cause a noisey rear end but how bad. You know what i mean. Thanks again for check it out.

 

[TheShabz]

are you contemplating whether to put 3.73 gears or whether used gears are ok? If the former, what you'll get is more oomph in the lower RPM range while sacrificing speed in the upper registers. If you're never in the 4000+rpm range you won't have to worry about it. If the latter, 20k miles isn't a big deal. A mechanic can correct me if I'm wrong here, but I can't think of a reason why it would be a bad idea, unless there's a breaking in process that somewhat contours the gears to the specific car it's on. I haven't heard of noise issues from a gear swap, so someone else will have to chime in on that.

 

[Bojingles]

Note that your 2013 will need this: http://www.americanmuscle.com/88-gear-assembly-2010.html

 

[Badboyz1620]

O ok thats guys.

 

[Husky44]

When you say "it" only has 20k miles, it makes me think you may be getting a full rear axle rather than just a gear set. If you're getting a full rear axle, then none of the info below applies.

If you're getting a 20k mile ring and pinion, I'm not sure it's worth the effort. Getting a used gear set to mesh properly in a new differential, without whining, is going to be a challenge. A new ring and pinion is <$200, and won't be as much hassle to set up.

Also, you may not need that pinion bearing linked above. Your car has pretty low miles on it; the shop doing your swap should be able to press off your existing bearing and re-use it. We did that on my 13, with about 3k miles on it. If they're careful and go slow, it can easily be done.

3.73s are definitely worth it, assuming you're running a 3.31 or lower (numerically) gear now. Dollar-for-dollar the best seat-of-the-pants performance improvement you can buy.

 

[Badboyz1620]

Cool i think im just going to get it new and bring it to the shop. I already have the used gears in my trunk but its no use to me based on what your say. How much did it run you to get yours done?

 

[Husky44]

I have a buddy that does this for a living who did mine for free. This is not a job for a beginner DIYer. I've done one gear swap myself, but it took a lot of to means I still had whine.

plan on 3 hours at your local shop rate, but don't take it to just any mechanic. You want someone experienced at setting up gears, like a driveline shop.

 

[harmon2011]

If you do decide to do the gear swap, the first thing you would need to purchase is a tuner to correct the speedo for the higher gear ratio. Take your car to a shop that specializes in mustangs. I got my gears done at the dealership where i bought my car.

 

[Husky44]

If you do decide to do the gear swap, the first thing you would need to purchase is a tuner to correct the speedo for the higher gear ratio. Take your car to a shop that specializes in mustangs. I got my gears done at the dealership where i bought my car.

Dealership can adjust ratio without a tuner if the ratio was an option on the car. Don't buy a tuner until you've checked with Ford service dept first. They should only charge an hour Labor if they can do it with their computer.

If they can't do it, buy the tuner, but no need to take it to a dealer, you can reset gear ratio yourself.

 

[harmon2011]

I have a buddy that does this for a living who did mine for free. This is not a job for a beginner DIYer. I've done one gear swap myself, but it took a lot of to means I still had whine.

plan on 3 hours at your local shop rate, but don't take it to just any mechanic. You want someone experienced at setting up gears, like a driveline shop.

He said he has a 2013 v6 mustang. If his car is a base model or pony/premium pkg model, the only gears that come with those models are either 2:73's or 3:31's so he would need to buy an aftermarket tuner to correct the speedo as ford won't be able to recalibrate a it wasn't an option.