driving in 4 low with hubs disengaged

[Eddo Rogue]

We used to do it all the time as kids for epic burnouts.

 

[Inbred Redneck]

Used to do that every day to go out my 1/3 mile driveway. Back out of parking space, put it in 2nd gear/4wdLo and idle all the way to the gate.
Sadly, that place appears to've gone away in the Bear Fire. Lost a pair of Festivas, two Yamaha Viragos, a few guns and 10K+/- rounds of ammo but saved Momma, important papers and the Ranger.

 

[scotts90ranger]

I pulled a garage over in 2lo in my '90 and broke a tooth off a spider gear in the old 7.5" when the rope broke...

Aside from doing silly stuff like that if you don't make a habit of it it shouldn't hurt anything, the 1350 and 1354 transfer cases are pretty tough. Top speed depends on tire size and gear ratio's, but I imagine getting the input shaft spinning 5000rpm makes those little gears really wizz around

 

[wildbill23c]

Used to do it all the time with my 88 F250. 1st gear 4 low, jump out and start tossing hay bales on the trailer.

Doesn't hurt anything as long as you aren't trying to pull stuff you shouldn't be pulling in the first place. Another benefit of old trucks with manual transfer cases and manual locking hubs, you have 2WD low range.

Low range you really are screaming at anything over about 30mph. Which isn't what low range is supposed to be for anyhow. I'd say 20-25mph is fast enough in low range.

 

[don4331]

Low Range in general.

For 30 mph, engine will be revving ~4k rpm (assuming 4.10s, 235/65R15s & low range), with transmission in 5th, transmission output/transfer case input is turning 5k rpms. Low range is 2.72:1, so the planets in low range are spinning 5k * 2.72 = 13.6k rpm. When poor little gears give up at those speeds, it is violent.

Which is why WranglerRubicons with their 4:1 low range now have "nanny" controls when equipped with automatics - to prevent users from spinning planets to 20k rpm. Wranglers with manuals didn't have the "nanny" control last time I checked.

 

[91 blue ranger]

I have 3.73s and 31 inch tires. And I can go about 23 mph in 5th gear @ 2,000 rpms.

 

[4x4prepper]

As others noted, no problems, doing 4lo with hubs disengaged. I pull a loaded tandem/double trailer that way with my 1985 B2 because the clutch/260+k 2.8L engine just can't handle the load on a hill. With 3.45 gears I hit 30 mph in 5th gear. I usually do it to get over the top of a hill at a stop light then on something that is level or downhill, I shift to 2hi.

I did find 5.13 R&P for my Dana 28, so, with 5.13 gears I should be able to avoid that. Not ideal driving that way and it does put some strain on the drive train, but, with common sense nothing is going to blow up.

I had a 1971 F-100 4x4 with a real 390 and NP435 with the single speed Dana 21? When towing heavy and on a hill, sometimes the only way I could get traction was to shift it to 4x4 (1:1 ratio) while in granny low. Sometimes you just have to do what you have to do to get going.