Since I now have about 3200 miles behind the wheel in an ECO Hub equipped truck, and drove in all kinds of conditions on my journey from Maryland to California, I thought I would post my thoughts. Keep in mind that these thoughts are coming from someone who only had about 4 miles behind the wheel with the stock hubs, so I essentially have zero point of reference in that respect.
The journey was uneventful, mostly, from a truck standpoint. Truck literally ran like a Swiss watch mechanically. I have some electrical niggles to sort out relative to the charging system, did the drive with the battery protection box disconnected because it kept disconnecting the batteries for no reason. I also have an oil leak at the front of the motor after the install of the AC compressor bracket, and I need to redo the install of the ECO Hubs because they are leaking. The seller of the truck installed the hubs for me, along with the AC and cruise control before I arrived, he has several businesses related to these trucks and habitats for them. He actually makes the AC brackets Acela uses . Anyway, he said he followed the instructions to a T and watched Mike's video, but something obviously happened because three out of four hubs are leaking, one front hub quite badly. Anyway, the seller is a super nice guy, I spent two and a half days working on the truck side by side with him and now consider him a friend,
On to the hubs. My truck is a 2008 M1078 A1R with a C7 running the 370HP tune with an Alison 3700S behind it. With the eco hubs, the truck goes like stink for a truck with something like an 18,000 curb weight. The new aluminum wheels/tires I had delivered to Maryland unfortunately seem to have some out of round issues so the vast majority of the trip was at 58 - 60 MPH. If the road was really smooth, I could drive 65 - 75 MPH comfortably. When I have the leaks sorted I'll spend some time with a go pro under the truck to see which tire/tires are the issues. This was the first vehicle the seller had installed Eco Hubs on and when he went into Baltimore to pick up my aluminum wheels he said he had the truck up to 80mph and it was the smoothest riding LMTV he had ever driven. Go figure, the steel wheels with zero balancing and crappy old 2008 tires had zero vibration issues and my new $5000 aluminum wheels/tires bounce like a poggo stick. Eco Hubs allow you to so easily travel at normal freeway speeds that the tires/wheels become the limiting factor. My truck is dead smooth up to 56 - 58 mph. Once you hit 60, it's a mess. With stock gearing, this would never be a factor.
Okay, back to the hubs. To me, the ideal scenario would be if the stock ring and pinion gearing was lower than 307. I don't need my LMTV to go 116 mph, and would prefer the lower gears off road. I haven't done any real off roading yet, but did put it in Mode for some short dirt excursions and would prefer lower gearing. It's likely fine for how I will use the truck, but I would prefer lower gearing off road. With the Eco hubs, 7th gear is basically an overdrive, my truck wouldn't shift into 7th until 67 mph, and to me, 65mph is the ideal cruising speed for the truck, so you basically end up with a 6 speed unless you plan to drive faster than 65 a lot. It just feels right at 65, but that's just my opinion. In the mountains in Colorado, the trans hunted back and forth between 5th and 6th a lot. I have the Alison software but haven't played with it at all. I hear it's quite powerful software, but tuff to get working when you aren't an Alison certified shop. Too risky for me anyway, so I plan to search out a good heavy duty Alison tech and see what can be done relative to tailoring the trans to the gearing. The truck will pull 6th for ever, lugging itself down and won't downshift unless you bury your foot in the pedal. I think tuning the trans to the gearing would make a huge improvement. Amazingly, I consistently averaged 9 - 10 MPG, hand calculated of course. That's pretty amazing for a truck of this size and weight, that is like pushing a hotel through the wind. My Ram AEV Prospector XL has 335/80 R20 Continental MPT 81's on it, is Cummins powered, and I get 12 - 13 mpg. It's less than half the weight of my S&S and waaaay more aerodynamic. 9 -10 in an S&S is impressive.
Now, one thing that is an absolute must in my opinion if you are going to travel in the mountains with an Eco Hub equipped truck is an exhaust brake. The switch in my truck is missing, the seller is sending me one along with some other stuff, and given the rust on the linkage of my pacbrake, I'm guessing it would stick closed if I used it right now. It will be on my shortlist of things to get working though as it is a must in the mountains with Eco Hubs. The gearing is so tall, when the road turns down hill, the truck just takes off. It's amazing how quickly it picks up speed. You're left with nothing but your service brakes without an exhaust brake and that isn't fun on long steep mountain grades. I guess I'm spoiled by the automatic setting on the exhaust brake in my Ram that just automatically modulates the exhaust brake to keep you at the speed you are going when you take your foot off the pedal. I know the application of the Pac brake on the S&S isn't great. I hear it way too aggressively downshifts the trans to 3rd gear when the Pac brake is engaged. Again, hoping either in the TCM or ECM this can be programmed out. If not, I'll wire around the truck electronics and just make the pac brake manual. The trans also isn't very aggressive about down shifting, yes you can manually down shift, but it's of limited help unless you downshift to the point you are piss winding the motor. On freeway off ramps, the trans doesn't downshift until you are almost at a stop.
So, I probably have said some things that would make one think I'm not totally stoked on the Eco Hubs, but that isn't the case. I would absolutely buy them again. Is it the perfect setup, no, but definitely better than 307 gears in my opinion for the simplicity and efficiency you gain by deleting the planetary gears, not to mention the cost savings. And, they would be the perfect setup if you installed lower ring and pinion gears. Drivability on road is really good and will only get better with some trans tuning. I'm guessing, either in the TCM or ECM, there is somewhere where the gearing is set. So now, the trans thinks the truck has stock gearing, but in fact the gearing literally twice as high. That has to affect how the trans shifts. I know it makes a huge difference in my Ram.
Sorry for the long ramble and rabbit holes into things not directly related to Eco Hubs