Do I need 4wd?

[mkosina]

2wd low-ratio - meaning transfer case in 4L but hubs unlocked ?
What's the scenario this would be useful in (aside from maneuvering a trailer, I can see that) - honest question, I am new to 4x4 driving.

I do recall reading some concerns about all the torque going down single driveshaft/axle like that, which is presumably not normal - anything to that ?

[loper]

You are correct, transfer case in 4 Low and hubs unlocked. You get the benefit of extremely low gears with easy steering (front unlocked, not binding up).

Lets you creep over or through things slowly and carefully, rather than using speed and momentum (with the associated breakage).

And yes, if you get too aggressive with the throttle, drop the clutch, or persist in wheel hop you are putting extra strain on things. The idea is to go easy and let the gears do the work.

[kbeefy]

@loper pretty much summed it up. Slow, precise maneuvering in tight quarters or backing a trailer.


I also drop it into low range if I know I'm going to be going slow for an extended period of time with an automatic, keeps the fluid circulating and helps the converter not slip as much, which keeps temps down.


As for 'over torquing' anything, it's the same loads as if you were in 4 lo and your front tires were spinning. Or in 2wd 2nd or 3rd gear. I've broken front end components far more often that rears. Shoot, I've broken more transmissions than rear ends or driveshafts, and they benefit from low range.

[mkosina]

Yeah ok, was just curious if there is any low gear scenario where it would be advantageous to have the hubs unlocked, specifically (aside from convenience of not leaving the vehicle and I suppose barring something like a stuck front diff that makes steering hard)

[b. rock]

A TTB conversion would be a smidge lighter than a solid dana 60 and reduce total lift height, but at this point you'd have to DIY it since Agile no longer does those. Or try and adapt one of the coil conversion kits for the trucks.

[deserteagle56]

Originally Posted by loper

You are correct, transfer case in 4 Low and hubs unlocked. You get the benefit of extremely low gears with easy steering (front unlocked, not binding up).

Lets you creep over or through things slowly and carefully, rather than using speed and momentum (with the associated breakage).

And yes, if you get too aggressive with the throttle, drop the clutch, or persist in wheel hop you are putting extra strain on things. The idea is to go easy and let the gears do the work.

^This.
I use 4Lo hubs unlocked a lot, especially going down hill where I want to hold down the speed but not keep riding the brakes. Low range and the tranny in 1st or 2nd keeps the van MUCH slower than in 1st high range.

[arctictraveller]

I do a lot of moderately difficult off road travel, and probably only use 4wd about 3% of the time. If you have some sort of limited slip or locker, along with airing down your tires and even better, traveling with a buddy, you should have very few issues without four-wheel-drive. If you travel a lot in snow, ice, mud, sand, or very loose rocks, then four-wheel-drive might be a good idea.

[Kibo]

Originally Posted by deserteagle56

^This.
I use 4Lo hubs unlocked a lot, especially going down hill where I want to hold down the speed but not keep riding the brakes. Low range and the tranny in 1st or 2nd keeps the van MUCH slower than in 1st high range.

I did this a couple of weeks ago coming down Loveland Pass to I-70 in CO due to skier traffic. So much easier creeping along at a constant speed instead of stop/go riding the brakes.

Not saying that's a good reason to go 4x4, though. I've been surprised by the situations that I did (and didn't!) need 4x4. Strangely, I've had to switch into 4Hi more than once for simple things like sloped/icy ski resort lots. I've seen high-$$ 2WD Sprinter vans get stuck at the bottom of the lightly sloped parking lot at Ski Cooper due to 1-2" of snow!

Even though we don't use 4WD 99% of the time, there are 2 major considerations that have made 4WD the right choice for us:

1) Our vans are heavy, and 4WD can be the difference between moving or having to extricate. For example, I remember one of our first camping trips where we pulled onto a dirt road in the dark to camp. Turns out it had rained earlier in the day, and we sunk into soft ground. In 2WD it was stuck, but simply switching to 4WD (no locking diffs, just LSD rear) got us unstuck.

2) We like to go where others aren't--which means if we get stuck, there's no one else around to help us! I travel with my family (wife and 2 young daughters), so getting stuck is more than just an inconvenience like it would be if I were on my own.

[The_Vermonster]

I'll echo what others have said.



1. the best part of 4x4 is Low range. I almost love it more for descending than anything. We drove up to the peak of a mountain and on the way down I used 4 low, and locked into 2nd gear. 2,200ft of elevation at a 10.2% grade and barely had to touch the brakes.

2. 4x4 doesn't replace a rear locker or other traction aids. I still carry Maxtrax and a snatch strap. A winch would be nice, but I don't do any crazy solo driving right now. There have been a few time where a locker or even LSD would have made things a lot easier.

3. 4x4 is really, really nice when driving in snow. Tires are important too, but it's not like you can easily change them out for the terrain or weather.

That said, a 2wd van with a rear locker is where I would start. You won't lose any money if you decided to go 4x4 later on. And it will let you test the capabilities of the van to see if you need more before dropping the cash on 4x4.

IIRC AJ's is not a very highly regarded 4x4 conversion. So I would do a lot of research first. I know there was a recent thread about it, but I can't find it.

[Greyswann]

All these guys are right. Working backwards from the adage "4WD just gets you stuck in worse places" is a thoughtful place to start. If you have experience on Forest Service roads you know that they can cover a broad range of condition. Old unmaintained logging roads can be all but impassable and the USFS has less and less funding to maintain them. Just look before you leap and dont feel bad about turning around. Carry self rescue gear and know how to use it. Remember life is one big adventure and even the worst problems are usually fun to tell later over beers