When to lock the rear axle?

[NewbieWonKenobe]

Hi there! Thanks in advance for your input.

My friend has a 2005 Tacoma 4x4 with locking rear differential. He asked me this question recently and I wasn't sure how to best answer it.

First, this truck would only be doing relatively easy off-roading. It only has street/4x4 tires and there would be no rock climbing or anything like that.

So, his question was this: Should I lock up the rear diff's as soon as going off road, before hitting an obstacle, or after getting stuck?

p.s. It would be desert off roading in the Phoenix area.

Thanks again!

[crawler#976]

That's a good question. I can make suggestions, but only seat time reading terrain can dictate when a locker is needed. Your driving skill goes a lot further than a locker will in most cases.

I'd say that 90% of the time you should lock it before you think you need it. Stuff like coming across a long section of two track that is heavily rutted and full of water is an example. Scout it first, and if it appears to be doable, go to low range, lock the axle and have a plan if you don't make it. Once stuck, it's unlikely a locker will get you out. It won't hurt anything on dirt to have it locked, but if it's not needed, don't use it.

The '05 Tacoma is like most vehicles these days in that the locker is only available in low range. There is a modification to the system that will allow you to use the locker in hi range too. It involves adding relays and switches to the wiring that controls the locker switch. There are detailed posts on how to do that on the TTORA forum. A rear locker in high range is very usable in sand.

First off, are the tires upgraded to an LT all terrain or mud tire? If not, that's the first thing that really, really needs to change. A P rated tire is, IMO, not even worthy of needing a locker. P rated stock tires are so thin in the sidewall, if you get into stuff that requires a locker, you're probably going to have other problems. With a stock '05 Tacoma (we owned a mildly modified '05 DC/TRD for many years by the way) on a good tire like a Toyo AT 2, Falken Wild Peak, Cooper AT, Toyo M/T, or GoodYear MT/R Kevilar that will not cut a sidewall very easily, you can get into stuff that may require a locker. Good tires also allow you to air down to get better traction, and a softer LT tire is less prone to damage than a P rated - P rated will cut if you look at'm funny. Having a good compressor is a requirement - the MV50 sold at O'Rielly's is a good example of a quality compressor that doesn't break the bank.

More often than not, I use mine in snow and sand. I'll lock up before venturing into deep snow or super soft sand. They also come in quite handy on some of the more technical trails I do. http://youtu.be/7xy6RI4Pqfc

Mud is a rarity, but we do find it every now and then, and a locker works well in that too.

There are exceptions to locking up an axle. On off camber situations, a locker can cause you to move sideways as much as forward. Again, it all comes down to experience reading terrain.

You should always go with at least one other vehicle unless you are very well prepared like we are. A winch and all it's associated gear, complete recovery gear selection including chains, shovel, hi lift jack, a real jack, a good spare.

Have fun, and Tread Lightly

Mark

[crawler#976]

If you'd like to join us, we will doing a group trip on the 9th of Nov. It's posted in the trips section, and will give the opportunity to see a nice group of vehicles, some stock, some not so stock, and to meet some very knowledgeable folks.

[flywgn]

That's a good question. I can make suggestions, but only seat time reading terrain can dictate when a locker is needed. Your driving skill goes a lot further than a locker will in most cases. ...Have fun, and Tread Lightly

Mark

Mark makes some excellent suggestions here.

Allen R.

[Explorer 1]

That's a good question. I can make suggestions, but only seat time reading terrain can dictate when a locker is needed. Your driving skill goes a lot further than a locker will in most cases.

I'd say that 90% of the time you should lock it before you think you need it. Stuff like coming across a long section of two track that is heavily rutted and full of water is an example. Scout it first, and if it appears to be doable, go to low range, lock the axle and have a plan if you don't make it. Once stuck, it's unlikely a locker will get you out. It won't hurt anything on dirt to have it locked, but if it's not needed, don't use it.

The '05 Tacoma is like most vehicles these days in that the locker is only available in low range. There is a modification to the system that will allow you to use the locker in hi range too. It involves adding relays and switches to the wiring that controls the locker switch. There are detailed posts on how to do that on the TTORA forum. A rear locker in high range is very usable in sand.

First off, are the tires upgraded to an LT all terrain or mud tire? If not, that's the first thing that really, really needs to change. A P rated tire is, IMO, not even worthy of needing a locker. P rated stock tires are so thin in the sidewall, if you get into stuff that requires a locker, you're probably going to have other problems. With a stock '05 Tacoma (we owned a mildly modified '05 DC/TRD for many years by the way) on a good tire like a Toyo AT 2, Falken Wild Peak, Cooper AT, Toyo M/T, or GoodYear MT/R Kevilar that will not cut a sidewall very easily, you can get into stuff that may require a locker. Good tires also allow you to air down to get better traction, and a softer LT tire is less prone to damage than a P rated - P rated will cut if you look at'm funny. Having a good compressor is a requirement - the MV50 sold at O'Rielly's is a good example of a quality compressor that doesn't break the bank.

More often than not, I use mine in snow and sand. I'll lock up before venturing into deep snow or super soft sand. They also come in quite handy on some of the more technical trails I do. http://youtu.be/7xy6RI4Pqfc

Mud is a rarity, but we do find it every now and then, and a locker works well in that too.

There are exceptions to locking up an axle. On off camber situations, a locker can cause you to move sideways as much as forward. Again, it all comes down to experience reading terrain.

You should always go with at least one other vehicle unless you are very well prepared like we are. A winch and all it's associated gear, complete recovery gear selection including chains, shovel, hi lift jack, a real jack, a good spare.

Have fun, and Tread Lightly

Mark

Great video of a full size beast CRAWLING through a garden of rocks!

I agree with what you said but would add that a little bit of tire spin and I mean a very little isn't necessary a indication that you need to engage your lockers. Years ago I found that I was getting a little sloppy with choosing my line because I could always just throw on the lockers and have them off set my choice of a poor line. So on a trip my son-in-law and I decided to travel the day without our lockers unless me made multiply unsuccessful attempts. It was an eye open as to just how sloppy we had become on choosing a line.

As illustrated in these two video's first with lockers and then without:

https://www.youtube.com/watch?v=zW_WstxuTMo

https://www.youtube.com/watch?v=NYsU18J5gmg

Practice, practice and then practice more and in most cases you can get by with very little use of a locker.

Thanks,
Fred
Explorer 1

[Scenic WonderRunner]

My thoughts on lockers have changed a bit now that I finally have one. I finally installed a Toyota FJ TRD Electric Locking third member in my 1988 Toyota 4Runner in 2011. Yes it fits with a couple of simple mods. Now when I hit the dirt, instead of getting out and flipping my hubs and putting it in 4WD right away, I simply hit my Locker button on my dash. I find that with just my rear locked I can make it over most terrain. If anything becomes difficult, I can simply put it in 4WD. If my hubs are already flipped, I don't even need to go outside. Best Mod I ever did to my 4Runner! Nothing stops me now!

[Scenic WonderRunner]

I found my locker retrofit story over at Yotatech. Thought I would share it with you. Best mod I have ever done.

http://www.yotatech.com/f31/toyota-e...inally-243769/

[David A. Wright]

I am late to the party as usual, but ...

My truck, as many here know, is a 2002 Tacoma TRD 4x4. During my early years with the truck, it was my practice to use the locker only when about to cover a technical section of trail. Being an e-locker, there were occasions when I already passed the rough spot before my locker finally decided to engage. The blinking light on the dash while the locker was thinking about it irked me.

At some point, a conversation with another owner/operator of a locked vehicle informed me he switched on his locker as soon as he hit the trail. For a few years I thought that not a good idea so didn’t practice it. But I’ve slowly came around to his way of thinking.

I’ve always been of the “if you don’t use it, you loose it” kind of thinking. Thus that is why my truck is in 4WD as soon as it’s off the pavement. I’ve seen far too many who boast about never engaging 4WD then hear bad noises and no pull from their front ends as soon as they needed it because nothing got moved and lubed for years. So I’ve adopted that thinking to the locker. I’m also a proponent of being less destructive to the environment and trail, as well as my truck; creeping along in low range with the rear locked avoids useless wheel-spin and the need for speed and momentum over obstacles. As I am getting older and less apt to be as adventerous as I once was since leaving the Eastern Sierra, the locker gets used far less than it once was. During hunting season is when the truck gets a good workout off road nowadays.

So presently, the locker generally stays turned off until I encounter a steep, rocky hillclimb. Then it is switched on and stays on until I get back to maintained dirt or pavement. That way all moving parts get used and stay limber. Yes, the outside rear wheel gets drug around a bit in turns, but in the dirt it isn't doing any damage at the speeds I’m traveling.

I know wheelbase plays a part in a particular vehicle’s dynamics, but my experience tells me staying locked in the snow works against my truck. I’ve taken my truck through snow deeper than the axles and sometimes the tires numerous times, I often switched on and off the locker to get a feel for what worked best. Leaving the rear unlocked allowed each wheel to get traction when it could. Locking up more often resulted in the back end of the truck digging in and the tires spinning, bogging the truck down to the point of stopping forward movement. Switching it off resulted in the truck returning to level and forward progress resuming.

Deep mud is a rarity hereabouts in the Great Basin and easy to avoid, so thus I have no comment on locked versus unlocked. As for deep sand, unlocked with reduced tire pressure has worked 100% in my case.