Difference b/t 4LO and low gears

[Dansnare]

Hi -

Here's a totally newbie question. I just got a new 04 V8 Limited.

What is the difference between 4LO and having the transmission in lower gears such as L, 2, and 3?

Thanks.

Dan

 

[Bluto]

Hi -

Here's a totally newbie question. I just got a new 04 V8 Limited.

What is the difference between 4LO and having the transmission in lower gears such as L, 2, and 3?

Thanks.

Dan

There is a transfer case after the transmission. The transfer case sends power to the front and/or rear axel. The transfer case has two gears, Hi and Lo.

 

[dcampen]

It is like a 10 speed bicycle where you have the 5 gears in the rear and 2 gears in the front.

With the 4Runner you have the 4 gear ratios (yes, I know, plus overdrive, I am ignoring this) in the transmission and 2 gears in the transfer case giving you a total of 8 gear ratios. 4Hi vs 4Lo determines the selection of the gear in the transfer case.

 

[Bluto]

http://auto.howstuffworks.com/four-wheel-drive.htm

 

[Dansnare]

Ok, so when do I want to go into 4LO and down shift the gears vs. going into 4LO and remaining in D?

Also is there ever a situation where I want to downshift and remain in 4HI?

What is the order of gear ratio (and therefore I assume power) in terms of the combinations of HI/LO and D, 4, 3, 2, L?

Thanks

Dan

 

[TranceKrayz]

4lo is for rock climbing and such where you have to SLOWLY crawl through places. 4hi is for normal driving and towing. towing is the only time where you'd need to downshift for engine braking (helps slow down your vehicle with the added weight of towing therefore reduces stress on brakes and brake wear).

 

[ToyotaDoodz]

Hi -

Here's a totally newbie question. I just got a new 04 V8 Limited.

What is the difference between 4LO and having the transmission in lower gears such as L, 2, and 3?

Thanks.

Dan

Welcome. It's a large gear reduction. I can give you a very practical example. Let's say you're coming down a VERY steep hill. In high range L (1st gear) you're engine braking will limit you to something like 30 mph. When in low range in 1st gear, you might hit 5 mph at idle speed.

It works the same way going up hill. In low range you can utilize the range of engine power with out going very fast.

(I've done this in a 2WD 4Runner)
Example: If you're trying to climb a 30 degree slope and all you have is high range 1st gear (L) you have to go a lot faster. Your engine's power curve comes on around 2500 - 3000 rpm and at the gear ratio of L, that means you're trying to climb this hill at 15 - 20 mph or your engine bogs down, you loose power and momentum and you're stuck. Been there done that at 10,000+ feet. Not fun or safe

Low range allows you to approach the hill at higher rpms but slower, safer speeds and you just walk right up the hill.

Also, in regard to off roading in rough terrain, you'd have to ride your brakes in high range L because the gear is too high for the engine braking to keep you going slow enough to be safe.

 

[Dansnare]

So does that mean that in non-towing situations, the power progression goes 4HI-D, 4LO-D, 4LO-4, 4LO-3, 4LO-2, 4LO-L?

So when going off road, that's the order in which I consider what sort of torque I need in a given situation?

Thanks.

Dan

 

[ToyotaDoodz]

No, you're either in Hi or Low range. Don't think of it as jumping back and forth.

I don't have the numbers here but your lowest high range gear is higher than your highest low range gear.

Low range is for very specific situations. Off road, steep, rough areas, OR you need to pull something heavy for a short distance like a big boat at a steep ranp.

 

[ToyotaDoodz]

To simplify, your V8 is a 5 speed.

L = 1st gear
2= 2nd
3= 3rd
4= 4th (no over drive availability)
D= 4th plus the capability of 5th gear over drive if warranted.

This is the same in Hi or Low range EXCEPT there's no overdrive in Low range.

Sorry if I'm being too simple. Not trying to insult.

 

[Dansnare]

Right. I get it. So in difficult situations like what you describe, I'm in LO, and then I have to decide based upon the situation what gear I want to be in.

Is that it?

And 4HI (with the V8) is for normal driving, while downshifting in 4HI would be for situations where I'm driving on normal roads at somewhat normal speeds, but I may have a particular need for engine braking such as when towing?

Dan

 

[ToyotaDoodz]

Yes. Exactly!

Off road, when going uphill I tend to just leave it in D and let the transmission decide. It's usually the downhill runs when I'll shift down. Same applies to the street as well.


Sorry if I was over simplifying before.

 

[Bluto]

I find the 4 Lo range can provide greater traction and control in the snow.

Less wheel spin and more engine braking.

 

[Dansnare]

Great thanks.

That was very helpful.

That Howstuffworks link was pretty good too.

Dan