Max speed in 4Lo?

Apologies. My comments had been deleted. Cheers.

 

You're locked out of 5th gear when in low probably because at that speed it is bad for the transfercase. It went on fine until 125Kish miles when it was totaled by someone that ran a red. That was also after adding a supercharger at 90K miles and many 4wd launches under boost.

 

Isnt it the same in 4lo?

Say i'm on a rocky dirt road, going 5-6mph, where crawling is not needed, and I am not getting stuck.

Am I better off putting in 4lo rather than 4hi?

I've been using 4lo mainly if I am crawling or want to go up/down a very steep hill. Not if I am just slow on a dirt road

 

I think that the torque converter can lock up at lower speeds, or at least slip a lot less in 4LO. I use it a lot in areas where I don't really need 4wd, but want to drive slow.

 

That's fine. You're slipping the convertor but not as much because both sides of it are closer in RPM. Going up something really steep in high would be like sitting and torque braking. The engine side is at engine RPM and the transmission side is stopped or moving slow which is what generates heat.

Think of a clutch, you slip it alot and it gets hot quick. Slip it a little and it still gets hot but not as quickly and not as much.

 

Wow that truly is a testament to how rugged those trucks are. I’m not sure if there is anything the 4Runner has in common with the tacoma’s drivetrain but I imagine it’s similar enough to share the same sort of ruggedness.

I have heard that the 4Runner shares the same platform as the FJ cruiser so I decided to look through an owners manual from one of those. Im not sure if the transfer case and axles are the same but I found a page in the FJ cruiser’s owners manual from a 2014 model that stated maximum speeds for low range based on what gear you are in. It looks like 41 mph is the max speed in 4th gear while in 4Lo. I believe you are correct in saying that you are locked out of 5th gear when in 4Lo.




When reading through my 4Runners owner manual some more, I did find a section about crawl control and how you must be in 4Lo to activate it. It states that when you get to 15mph, the crawl control feature is temporarily canceled until speeds fall below 15 mph. I’m kind of reading between the lines but to me that says you can take 4Lo up to 15mph.

I also found a gear ratio calculator online and based on the transmission and transfer case gearing, doing 20 mph in 4th gear in 4Lo is about the equivalent of 53 mph in 4th gear in 4hi which I think is completely reasonable.

Long winded but I guess that’s my rationale for concluding that I didn’t damage anything.

 

That looks like the speeds for the 6 speed manual. I say that because H is the standard position because all the manual FJs were AWD.

In the end, the ECU is not going to allow you to do something that will cause damage unless you really try.

 

Don’t worry about it - you put more stress on everything from lugging the engine down with heavy throttle at low rpm’s in high gears (a hard situation to get in on an automatic) than from lightly loaded high revs in low gear. It’s very hard to damage a modern vehicle from high rpm as the rev limiter will kick in long before damage occurs.

the bigger risk with the locker is making the mistake of engaging it on a high traction surface and then trying to turn quick at speed, putting a lot of stress on the diff gears. Follow common sense and only use it in legitimate off-road situations and you should be fine.

 

It seems like I've been using low range vs high range mostly properly then as I mainly use low when I would need to "work the clutch" in a manual and high when I can just

I used to have a manual 2000 Jeep Wrangler on 35s.
I've always wanted to get a 4R but couldn't afford one back then (in my 20s)

I sold it a few years ago and love the 4R although off roading in an automatic is completely different. I never had to "think" about high vs low range in the jeep as I had to change it instinctively.

Wish I never sold the Jeep, it was a great one and a good engine unlike the crap they sell on the newer jeeps. Similar to the 4R in a way, 4.0L but straight 6 instead of V6.
I would have loved to have both the Jeep and the 4R. At least now I know I never plan on selling the 4R. Hopefully will get another TJ one day.

Anyways I'll stop boring everyone with my stories,
Thanks for the explanation, we learn something new everyday!

 

When you’re looking at a rutted muddy two-track that disappears into a brown pool of tepid water of unknown depth and re-emerges on the other side, you lock it into 4LO, swallow hard, put the throttle to the floor, watch the tach, and pray you make it to the other side.

 

Yikes! I’m not man enough to attempt that. I’d find a path around it. I dislike mud.

 

Not me. I put on waders, and grab a stick. Walk through the whole puddle and back, checking depth, bottom composition, and looking for rocks

In Wisconsin, a lot of our "holes" have rocks in them. The "send it" method is usually a recipe for broken parts.

Also, if I'm going to send it through something sloppy, I go 4hi, and kill traction control. Wheel speed is important for clearing the tires.

 

I keep it about 15 to 20 mph in 4lo or should I say my rpms are at about 2500ish

Here's a few reasons why you not only want to be in 4lo but "need" to be in 4lo, when you're wheeling up a steep incline or even at elevation 4lo not only gives you more torque but keeps your converter locked and will keep your transmission cooler. I've been on some trails where my friends wouldn't listen to my advice and kept it in 4hi and each time all their transmissions overheated (where you get the actual transmission overheating sign on your dash)

 

I had a 2006 LJ Rubicon and it was rock solid with no issues in seven years of ownership. 2006 was the last year for the TJ's and LJ's. I wish I had kept it as well. 4.0L Straight 6 - lots of torque!

 

LOL honestly I could have sworn I saw that on the manual but I misread it. After going though it again I realized it gave speed limits to switch into 4H

 

No worries. Would have been nice if 4Runner manual included that info so we don't risk. Would have been really helpful in tricky situations like on sand.

 

If u are going that fast in low, are you in a situation where you need a low gear?

 

I run 4L most of the time. 4H for snowy/icy roads. 4L for rock crawling and deep sand, especially when climbing sand hills shift to a higher gear to keep my momentum up. This keeps the engine from bogging down while climbing sand hills. I’ve done this with all my 4Runners since 1985 never had an issue.

 

I let the 4runner speak to me in 4lo. . I dont pay much attention to the speed, but rather just by listen and feel.

I prefer to put the transmission in S mode in 4lo because the shifts in D tend to be jarring with all the reduction. So Id rather lift throttle, shift, and then roll on the gas once the transmission is in the next gear.

Depending on the situation, I might be running higher rpm, or lightly coasting in 4th. If you’ve ever driven stick, it’s easier to tell when you need to get out of 4lo. The engine wont blow simply because of engine speed (below redline of course).

Regardless of speed, shock-loading the driveline is much easier in 4lo. You have to be more tender on the gas (especially at higher rpm), so don’t poke/lift the pedal too roughly.

If using S-mode for engine braking in 4lo, be careful if you downshift, since the rpm limiter cant limit rpm when the wheels are driving the engine. While the transmission might not allow a shift if it will put it past redline in that moment, you might overrun redline if you end up accelerating downhill. I doubt s-mode will upshift to protect the engine in this situation, since toyota probably understands somebody depending on that much engine braking will probably get killed if the transmission decided to shift on its own.

Basically, I dont think a vehicle speed limit for 4lo is enough to protect the 4runner, because it’s possible to break things anyway if you dont use a little mechanical sense.

 

It’s interesting that the chart says “max allowable speed when maximum acceleration is necessary”. It’s seems like it’s a maximum speed that will guarantee usability of the gear, including situations beyond that speed (up to redline presumably lol).

It’s hard to put down a speed limit for 4lo. As a manufacturer, they probably could also be blamed when somebody screws up and breaks something under the speed limit for some other reason.

 

The internet would have me believe that if I went over 10 mph in 4Lo that my transfer case would spontaneously grenade itself but you seem like you’re speaking from first hand experience so I’m gonna go with your advice. My 4Runner has been driving great lately but I haven’t had a chance to find some trails to explore in 4wd so your post gives me some peace of mind. Much appreciated!

 

When you’re in 4Lo and climbing sand hills or in a situation where you need to keep momentum up, what rpm and speed range are you in?

 

There's no set speeds for anything. You just have to go for it and see what works.

 

The 'feel & sound' is the approach I've taken for a very long time, it always came out ahead of watching gauges. When things got 'interesting' in some of my old trucks, I would check the temp. and oil pressure, but other than that... "You must become one with your4Runner!", listen to it!

 

You mean like the 5-speed anti-theft device in my daily driver Scion xB?

 

RTFM

 

One thing, but why is Neutral needed to engage 4 Lo? Like what mechanically is going on that requires it before you can engage 4 Lo?

Also didn't know low speed in 4 Hi strains the drivetrain, good to know.

 

I always thought neutral exists so the vehicle cam be pushed or towed.

 

Before yes but now it just confuses people.

 

When you're in the middle of nowhere, sometimes you have to do things you wouldn't normally do.