Gear Splitters
In another year and a half, we will be taking some extended trips and pulling a toad. Although I have been overjoyed and very impressed with the Banks, the Ford V 10 has a "gap" between second and third gear. This means that when towing, on some hills, third gear is too high and second gear is too low. Since top speed in second gear is a bit over 40 mph, this means that you must down shift to second, since third gear is not low enough to hold the speed, and since second gear provides enough power but is a little too low, you must hold at 40-45 all the way up the hill to prevent excessive rpms. Not terrible, but there must be a way to make things better for those few times- I would estimate 20-30 % of mountain driving- when the gear gap causes a problem ( severe pilot impatience).
Enter the Gear Splitter. There are basically two companies that make gear splitters- overdrive or underdrive units; Gear Vendors and US Gear. I have a US Gear model, and my comments apply to that brand.
There is a small gearbox that bolts to the back of the transmission and it has two "speeds" in the gear box. One is "normal", and the other is "low."... This effectively gives you 8 forward gears instead of 4. Technically the splitters come in either over or under drives, but on a practical basis in a motorhome, underdrive is the only reasonable choice. The gear box has it’s own special fluid, which should be change about every third engine oil change.
The gear splitter control button is mounted on the gear shift lever. It is activated by pushing the "high-low" button while the engine is under a slight load (gentle pressure on the accelerator). Then let up on accelerator pressure. A heavy "clunk" will be heard and felt as the lower gear set is engaged. Then resume the accelerator pressure. The same procedure is used for shifting back from "low" range to "high" (normal) range.
When in normal, everything is exactly the way is was before you added the unit. But when you shift into "low" range, you get four gears, each of which is half way between your "normal" gears. Effectively this means that when you are pulling that hill you have to drop from fourth to third. As the hill steepens, you know that third is not going to hold your speed and that second will be too low a gear, so you engage the gear splitter (shift it to "low") and you are in third gear of the low range, which is just right.
The other choice is to shift the gear splitter to the low range as you approach the bottom of the hill. This effectively puts you in three and a half, half way between fourth and third. Now as the hill steepens, you push in the button on the end of the gearshift lever (ie shift into "third"), and you shift from three and a half down to two and one half (half way between second and third).
The US Gear unit also has the advantage, since it is a direct gear to gear unit (no internal clutch), that it can be used as a downhill engine brake. The Gear Vendor brand has an internal clutch, which shifts more smoothly, but it can not be used as a downhill engine brake. Again, going down that hill, we drop from fourth to third, but still are gaining speed. We know that we could slow to 40 mph and shift to second, but with the gear splitter we have a gear which is between second and third and just like going up the hill, this ends up being the perfect gear for coming down the hill. On steep hills you may need to brake occasionally, but nothing like when in normal third gear. When I first purchased the gear splitter, I assumed I would use it mostly for climbing and maybe a little for downhill engine braking. Now I feel that the downhill braking is more important and more used than going up hill. Consider this when choosing brands.
The Gear Splitter will be between $2500-3000, installed.
I would definitely recommend doing the Banks first. There is no doubt you will be impressed. Then see whether you think you need more rpm between your stock gears. Consider how much you drive in the mountains. Consider how much you tow. How much do you need that lower gear for braking downhill in addition to hill climbing. And consider how much it actually bothers you to go 35-40 mph up those hills.
Addendum After three cross country trips from Oregon to Maine, I remain overjoyed with the splitter. East of the Rockies, I did not use it nearly as much as in the west, where the mountain roads are steeper and longer. I did use it on the 17 percent grades in Nova Scotia. And again, it has it's greatest benefit when towing. But I still love it for downhill braking.
Doug