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I haven't even tried yet. I barely got it done before bedtime on Sunday night and since then I've only had time to drive it to work and back LOL. I'll check it out soon and let you guys know!
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No break in donuts? This is shameful! This is how I broke in my new front end.
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I dug some nice furrows in my gravel driveway with the new lockers on. Does that count?
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Only if you had a grin from ear to ear!
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Have you had a chance to get a feel for the 5.13 diff gears on pavement yet? Wondering how 1st and 6th gear are performing?Well it's a few months later but I finally had the time and motivation (UBB) to get these axles swapped in, and I finished it up yesterday. I'll do a thorough writeup about it along with videos for our YouTube channel soon, but I wanted to let those who have been following this thread know that the deed has finally been done
I ended up just using the AUX switches since I was running out of time. I used switches #3 and #4 as they're 10-amp and #1 & #2 are 30- and 15-amp, respectively (rather save those for something that needs bigger draw). I read somewhere that the lockers only need a 10-amp circuit so hopefully that will work out OK. They do function correctly.
I also used the ProCal tune, really just for FAD delete. I'm not sure if I did it right, but I'm not getting any codes or other malfunctions. When I downloaded the tune to the ProCal unit, I was prompted with the question of whether I was installing any of the Ford Performance aftermarket FDU's. I technically was not, since it's a used factory M210, but I lied and told it I was, figuring that's what it wanted to hear, so I clicked the part number for the 5.13-geared one. It downloaded both the tune and some sort of DCLM -alphabet soup file. My best guess is that extra file is the re-write for the FAD delete. When I did the procedure to load the tune into the Bronco, there was no mention of FAD delete, or any prompting to do anything with that other file. Nor was there any mention of FAD anywhere in the settings in the ProCal unit. So I'm guessing it was just an automatic, invisible thing that it does if you tell it you bought the aftermarket FDU.
I still had a half tank of 87-octane (I'm a cheapskate) in it so my first trip was to the gas station was to put some high grade in it. The gas station in my little one-horse town only had 91 so I topped it off with that. So far no pre-detonation or any other problems I can tell.
In addition to the lower gears I simultaenously installed bigger tires. So I went from 35's on 4.46 gears to 37's on 5.13 gears (Nitto Recon Grapplers). That yielded a modestly lower final drive ratio than I had before, but that I thought would be better for my commutes than if I'd gone all the way down to 5.38. Since I did all this at once it's hard to judge what part of the "seat of the pants" difference is due to the tire and gear change versus the ProCal tune. But I do like it. It seems almost as peppy as it was in bone stock form with 30" tires on 4.46. Certainly better geared than the 35's on 4.46. I think the lower gears will come in handy off-road, even though it's not quite the tractor it would be had I gone to 5.38.
On Wednesday morning we're leaving for United By Bronco at Sand Hollow, Utah, so I hope to get at least a few easy break-in miles on it before then, though I know I won't be able to meet the conventional wisdom on break-in procedure. At any rate, I'll get some good seat time in it later this week so I can give a better reaction to the performance improvements.
Until then, if anyone has any questions feel free to ask.
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Yes we've driven it quite a bit so far. Back and forth to UBB (about 700 miles total, mostly highway, towing a small trailer), a good range of different trails at UBB (rock crawling, sand dunes, canyons), plus about a week of commuting (about 60 miles a day, freeways and surface streets). My conclusion is that the 5.13 gears were the perfect choice. 6th gear is usable now, first gear is better for starting from a stop, and more useful in stop-and-go traffic (I used to sometimes use Crawl). On-roads and highways it's just right. And off-road it's perfect also. In Crawl gear, with the 37's it can easily pull itself up any obstacle no matter how steep as long as it can get traction. And regular first gear is now more useful, leaving Crawl as more of a special-purpose choice than it was before. We're very pleased with it and I really don't see how I would have benefitted going to 5.38's instead.
That sounds awesome. I would love to get some 1st gear grunt back.
I'm not sure many people would notice much difference between the 5.13, 5.29, and 5.38 options so probably just choose the best price.
I ran some quick calcs on Grimmjeeper at 70 MPH, nominal tire size not actual:
6th 4.70/33s 2164 RPM - my starting point
5th 4.70/37s 2318 RPM - where I am now which feels great
6th 5.13/37s 2107 RPM
6th 5.29/37s 2172 RPM
6th 5.38/37s 2209 RPM
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