The rear locking differential is to be used in extremely difficult situations. It's VERY effective but prone to serious damage if not used correctly.

Personally, I don't use it unless I get stuck using the low gearing when climbing or having lost traction on the rear axle thus immobilizing the vehicle.

Remember, ALWAYS keep your front wheels straight when your rear diff is locked or your diff will suffer. That's because the 100% locking diff makes the two rear wheels turn at exactly the same speed no matter what so the surface needs to be extra slippery or one wheel off the ground.

Every situation differs but I think you get the picture.

To give you an example, we got immobilized with my dad's Navara yesterday, rear right wheel off the ground and front diff high-centered, I tried reversing in low which didn't work, and then locked the rear diff for only two meters of reverse (front wheels straight even though there was much ice underneath).

Concerning Hill Descent I can't help cause I don't have it.

 

you could leave it locked while offroading without any negative effects, its not going to hurt anything.
or you could just use the locker when you are approaching a difficult obstacle, and switch it off on easy stuff.

hill descent is not really needed, just use your brakes and common sense.

 

Well beef your perception of "off-roading" exceeds by far what common people like the majority of us do. You have your wheels hanging all the time climbing huge rocks and boulders doing technical climbs whereas most people use their trucks on trails where all wheels have traction most of the times and wheel spinning is minimal and this can stress the locking diff.

I have tried making a very light turn with low gear and locked rear diff (at very low speed) on a dirt road and it was quite audible that the rear wheels where getting stressed. Of course this would totally change if one wheel was in the air.

No matter what we say in here it's a matter of personal experience and skill, the only way for Martin to find out is taking his vehicle and putting it to the test.

 

I have tried making a very light turn with low gear and locked rear diff (at very low speed) on a dirt road and it was quite audible that the rear wheels where getting stressed. Of course this would totally change if one wheel was in the air.

i wouldn't describe that rear wheel sound you described as creating stress, i would describe it as "overcoming resistance."
what you hear happening is the wheel inside the turn spinning slower then the wheel on the outside of the turn, and one of those wheels is loosing traction and spinning. there is no harmful stress, because the energy is released long before a damaging amount of torque is applied to the axle or its parts.

you could drive around on pavement with the rear diff locked all day long and there probably wouldn't be any damage to the rear axle or differential at all because the tire's contact with the road is not capable of binding axle shafts to the point of damage. the main ill effect is going to be the premature wear on the rear tires from spinning at different speeds during cornering. the stress is going to be released through loss of traction from the tire to the pavement.

i understand what you are saying when you describe stress in your above statement, but technically just accelerating creates stress on the rear drivetrain in the same fashion, but the torque is directed to one wheel.

that said, my rear diff gets locked and stays locked as soon as i'm on dirt, and i would be confident doing the same in any ordinary truck.

 

Interesting perspective, however I've been told by several engineers that turning the vehicle with locked diffs while on roads with decent traction and all wheels on the ground will break the diff.

As far as I know there are many types of locking diffs and some of them allow your approach, I can't remember their brands though.

Another point is that the locked diff is to be ran at very low speeds (can't remember the limit) and not all dirt roads are to be driven that slowly

My knowledge and experience stops at this point but I haven't needed it for the last 2 years because my suspension works really nice and at Low I've gone through washed out roads and holes with zero spinning compared to my dad's truck.

 

there is nothing wrong with erring on the side of caution. nothing that you are saying is really wrong, its just very conservative and safe.

i don't think the main concern with using a locking differential is damage to the drivetrain. i think the main concern with using locked differentials is inappropriate use that causes unexpected loss of traction- because the way it changes the handling characteristics of a vehicle at various speeds, and on various surfaces.

nissan engineered the 2nd gen frontier to only be able to use the locking rear diff under a certain speed (i think 7mph), and the truck must be in 4lo. particularly because its impossible to forget to leave it on and proceed to drive on a paved highway like normal.

 

So I picked my truck up at the end of the 2010 model year so pickings were a bit slim. I'm not gonna say I settled on my truck but I did get features I wasn't after. The hill descent control being one of them. Another feature that I have allows me to take my foot of the brake for it keeps the brakes applied for like 2 seconds giving me time to move my foot to the gas pedal. Supposed to stop the truck from rolling backwards. I've played with it and it works but it's certainly a feature I wasn't set out to have.

Thanks for the advice on the locking rear differential. Are there only 2 generations of Frontiers right now? 2nd gen is everything after....2005?

 

^
That is correct, 2005+


You're not missing much with hill descent though, its better designed for less-experienced drivers that are descending steep hills and want to have that extra control and ability to take it nice and slow

I imagine if you were hauling something heavy or had a heavy load it would also be useful in mainting control down a steep decline, i've used it a few times with a load but nothing I really couldn't of handled myself

 

Put a small lift on it, some 285,s and hit the trails. Best thing to do is to try and find some people in your area that go there and wheel with them. If it is a group or club there should be a few of them there that would not mind showing you the ropes. Best of all you could ride some trails with them and learn as you ride.

 

What he said! If your near GWNF, there's quite a few people on here that go wheelin there. Looks like a blast everytime they go.