Hi Everyone!




I am considering swapping the 3.73 gears in my 2013 superduty to a 4.30. I just found out this is the highest ratio available for my truck. Im running 37's and have the 6.2 gasser. Wondering if anyone has done this swap and if they think its worth it? I really wanted to do a 4.88 but looks like that wont be an option anytime soon. Im being quoted between $2200-2400.00 from multiple shops here is San Diego. Appears this gear set is a bit pricey.


*I do light towing once a month - trailer with rzr and or quads
*Lots of stop and go to and from work
*daily driver


Any thoughts and or advice would be greatly appreciated!


Mike

 

$1k an axle is perfectly fair, so $1.2k an axle might just be normal inflation in the last few years or living in CA.

Have you looked aftermarket for gears deeper than 4.30s? These guys will know the real facts and would be the best people to find 4.88s if you want them:
Customer Service - RANDYS Worldwide Automotive

Run the numbers on the gear sets. Opinions and what people have done are great comparisons, but for your specific situation I'd look at it more from the angle of: pick where you want to end up RPM wise, and back into the gear numbers based on your tire size from there:
http://www.4lo.com/calc/gearratio.php

 

The dealer is the cheapest place for the correct gears. The truck has a super 60 and the rear is really a 10.6. The older 9.75 Dana 60 will fit as well as the older style 10.25 gears. With the correct bearing you should be able to do 4.88s. I did 4.30s which 700 isn't far off for parts alone plus labor. I did my own install

 

I've done the exact same thing you are looking at. Had 3.73s went to 4.30s, I also have a 6.2 gas and 37" tires. Cost for me was just under $2000, gears and labor. If you have the electric rear locker, then 4.30 is the lowest you can go due to the odd ball 37 spline axle shafts. If you don't have the electric locker, then yo can go lower as the shafts are 35 spline. At least that was the reasoning from my Ford dealer.

It was the best thing I've done to my truck yet. It helps put the the truck back into the power band at highway speeds, at 80 I'm turning about 2100 rpm. The off the line and around town driving is greatly improved.

 

The axle shafts are still 35 spline. The e-locker can also be put into an older 10.5 axle and will mate to those shaft, granted you have to run power to engage it. The odd part, which is better, is the pinion is 37 spline and bigger than the older 31 spline. Any deep ratio for a 10.5 is actually 10.25 gear set so to make it work you need to use 10.5 bearings. The deal is nobody has addressed the bearings to put a 10.25 pinion in the newer housing. I'm sure there is a bearing out there but me like everyone else doesn't feel like buying the extra parts or have the time to try it. Unless Randy's has done some research on that topic in the last year they won't help you because they didn't know either. There isn't an aftermarket gear either. I have a brand new "Yukon" 4.30 set in my garage that is a repackaged ford set. BTW I will make an offer you can't refuse if you want to purchase it...it's brand new. Besides buying that gear from me, the next best place is your local dealer, they are cheaper than the "aftermarket" ones. Also some places will try to sell you a cheaper front gear set. It's a not a super 60 gear. Granted the regular 9.75 dana 60 will work the super 60 is 10 inches and the pinion isn't crowned making it stronger. As far as driving around 4.30s and 37s will put you back to a stock smaller tire truck with 3.73s. The 6 speed really masks the need for gears with bigger tires until you hit 5th and 6th gear so that will improve. Unless it's really bothering you or you plan on towing a good bit I honestly can't say it's a great investment for the cost. I was able to pull a car trailer with 3.73s and 37s with no issue but I will say isn't better with the gears.

 

Hi Everyone,




Just thought I would update this thread. I ended up doing the 4.30's this weekend. The gears were installed including front and rear magtech diff covers. Ended up costing me 2800.00. Little more than I wanted to pay but its done.


As far as performance the truck cruises at 70MPH at about 2000rpm now. Im still breaking in the gears so I have got on it to see what the 0-50 and up is. So far Im happy with highway speeds as truck does not downshift on hills. True test will be after break in when I punch it and tow my trailer this weekend.


If Im still not happy with the performance Im seriously considering the whipple SC.


Mike

 

I also did the 3.73 to 4.30 ratio swap. Best money I've ever spent on a performance enhancing equipment. I'm running the standard 31.5" tall tires and it made a tremendous difference in how the truck pulls away from a stop light and the slush-a-matic doesn't search for gears on hills and overpasses nearly as much with the 4.30's as it did with the 3.73's.

It's not a cheap upgrade but in the long run it's worth every dime.

 

The 4.30 gears are good combo with the 6.2l and STOCK -33" tires. For 37" tires 4.88s are a much better choice than the 4.30s but the 4.30s are still better than 3.73s by a long shot. Best to cry once and go to 4.88s if you are running 37s.

 

Your right, 4.88's would have been best but they don't make them yet. 4.30's for this year truck are all that have been cut so far. I called Ford and spoke to a number of driveline and off road shops.

 

I could have swore the F-450 chassis cab 4X4 used the super 60 up front. The 4.88 gears have been an option for a long time on the 450 and 550 with the 6.8l engine. There will be a lot of super 60s in junk yards in the future so the aftermarket (like Yukon) would be smart to offer so gears for them.

Edit: Found an article with part #s. So they do make Super60s with 4.88 gears apparently.

http://www.fourwheeler.com/how-to/tr...60-front-axle/

 

Yes 4.88 and 5.38 are factory options in for certain trucks. Only issue is 4.30 is the deepest option for the 37 spline 10.5. I'm sure you can change the yoke and figure out how to run the older 31 spline set but I don't have the time to play with it. I put 4.30s in mine with 37s, no issue. If you had the small tires and 3.73s the 4.30s will put you right back to stock