When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Towing question - went horse-camping last week with a group, three diesel-duallys [2010 f-450, 2008 f-350 and 2006 GMC 3500] towing 3H and 4H LQ trailers from 12,000 - 14,000 lbs. There is a 9-mile portion of the trip where the road climbs approx 3,000 feet and we had long discussion about best method of towing up that grade. GMC guy swears it should be 4-wheel low; both us Ford guys left tranny in D , 2-wheel and had no problem. temp was 102 at the bottom of the grade, watched guages and saw a tad of movement but nothing even close to getting hot.
Four wheel low is the way to go if you're on a dirt road at low speed. Four wheel high if it is a low traction, higher speed. Two wheel high if it is a paved road at any speed.
Assuming the speed was in 30-40 mph range, Low on transfer case and 4th gear on the transmission is close to 2nd gear on high. I might be a gear off, but the engine doesn't care how the final ratio is done as long as it gets its good rpm range.
4WD on dry pavement on truck with no center differential makes front axle working partly against the rear axle, as tires are never the same, so that is something I would avoid.
Yeah, low range on the transfer case and higher gear on the transmission could give you roughly the same final drive ratio. The bigger problem is the use of 4WD on pavement. If you had manual hubs, you could leave them unlocked which would basically give you 2wd Low. The only advantage to this would be getting the load moving from a stop, but if getting moving is that much trouble, the load is WAY too big for the truck anyway. 3000 feet rise over 9 miles means you are averaging roughly a 6% grade, which is really not that steep by mountain standards. Should be zero problem with this at all, especially with a diesel. I would be more worried about the trip back down.
If it's dry - no 4x4 even if it is a straight paved road...
if it's wet, dirt, or mud, then maybe 4x4 high if slipping...
if the speeds are 25 mph or lower than maybe low range, but why ?
the stock config can pull VERY well from 0 thru 80 !!! if it has to, it will go into first gear, but let the truck's computers tell you that - that's why they call it an automatic
99% of the time I'm not even in tow haul except to slow down or coming down hills...
Yeah, low range on the transfer case and higher gear on the transmission could give you roughly the same final drive ratio. The bigger problem is the use of 4WD on pavement. If you had manual hubs, you could leave them unlocked which would basically give you 2wd Low. The only advantage to this would be getting the load moving from a stop, but if getting moving is that much trouble, the load is WAY too big for the truck anyway. 3000 feet rise over 9 miles means you are averaging roughly a 6% grade, which is really not that steep by mountain standards. Should be zero problem with this at all, especially with a diesel. I would be more worried about the trip back down.
I hope newer trucks pull better on 1st gear. My 2000 with 4-speed auto is so lousy that I have to switch to low for maneuvering on my driveway. Cold engine with 1 on high will not move empty trailer even on minimal incline. My front hubs leak the vacuum, so I am not worrying about stress between the axles. I am thinking about capping off the hose and leave manual hubs only. I never need 4WD, but low gearing often is a must.
Yeah, low range on the transfer case and higher gear on the transmission could give you roughly the same final drive ratio. The bigger problem is the use of 4WD on pavement. If you had manual hubs, you could leave them unlocked which would basically give you 2wd Low. The only advantage to this would be getting the load moving from a stop, but if getting moving is that much trouble, the load is WAY too big for the truck anyway. 3000 feet rise over 9 miles means you are averaging roughly a 6% grade, which is really not that steep by mountain standards. Should be zero problem with this at all, especially with a diesel. I would be more worried about the trip back down.
The trip down is 4WD low in 3rd gear. piece of cake, stays right around 18-20mph and tap the brakes maybe twice.
You'll know when you need low range on dry pavement. For me, it's been during steep loaded descents. I have manual hubs on my '02, and run with them disengaged (unlocked) in 4-low. Doesn't hurt anything since the front wheels freewheel.
4 low is spinning a sun gear and many little gears in the transfer case making it heat up allot! 4 low should never be used for "driving anywhere". 4 low is for getting unstuck or maybe moving something heavy around the yard. There should never be any distance traveled in 4 low.