will I regret no rear diff lock?

[simonfish]

Hi, getting very close to buying a SWB R DiD.

I will be swapping the tyres for Cooper ATR's and am undecided if I should tick the 'rear diff lock' option.
I don't do extreme 4wheel driving, but do want to get up to Fraser Island (sand) once a year, but mainly drive in gravel and dirt (and on the highway) to get to favourite camping and fishing spots in NSW.

The reason for not ticking the box is
1/ there is a 2-3month wait for delivery
2/ $1,000 cost

Seems like a lot of money that I could spend on camping gear sitting in the diff that I might never need.

Would appreciate advise from people with SWB who did tick that box.

cheers,

Simon

[matthewfnorbert]

simon i just went off road with my swb and 2 mates (yes adam i have some friends!), they had a new patrol and new navara tdi manuals.. the swb wiped the floor clean with them. i spent the whole day in 4H or 4Hlocked centre (the auto did so well did not even use the low range).

on ramp overs they got stuck
on creek crossings with large rocks they got hung up with 2 wheels in the air, the paj traction control easily pushed me out even after stopping mid way with the paj rocking on two wheels only..
approach and departure angles were king! the patrol lost a rear tail light and the navara the back bumper pushed up..

did some very tough stuff and the traction control worked very well, cant see the diff locker doing much better unless you are going crazy at which time you are probably damaging your truck or doing trials.. for 99% of work you could easily do without it.

thought i read somewhere here that the press said it is better with traction control than locking the diff?

[macguru]

I have done a fair bit of offroad with my SWB petrol (no diff lock) and agree that the traction control is excellent. As I have a petrol, I probably use low range more than a diesel driver, and I have kept moving with the TC acting on a couple of wheels so I was impressed. I dont plan on doing anything like the 4WD TV competitive hillclimbs - i would think you would need an older truck with raised suspension & big tyres for that - and in those older trucks their front & rear difflocks would compensate for the lack of traction control.

I am not sure if the rear only difflock on the Paj is useful in normal 4wdriving - whatever that is. I wonder if anyone has been so stuck that they needed to engage it ? (and so stuck that the traction control would not cope ?) The usual problem other people have had (that i have seen) was getting hung up with one wheel on eack axle slipping - and thats where the TC shines

[simonfish]

Thanks guys, you are telling me exactly what I wanted to hear !!

[marquis]

Been over stockon, simpson, cape york (amounst other places) and the pajero has never needed a diff lock.

[Walker]

simon i just went off road with my swb and 2 mates (yes adam i have some friends!)

No you don't, they are just after your money!


If you are doing not much more than Fraser then you will not need a locker.

I have ordered one for mine only because they threw it in as part of the deal. For the sort of stuff I will use the Paj for (I have an old Range Rover for the hard stuff) I don't think I will ever need the locker but if you are getting it for nothing I might as well take it. It is mostly on slippery rocky steep hils where the locker will work best. Because it is proactive it means you can use a bit less right foot and hopefully save busting a diff or axle where hard wheelspin may break something.

[MinniTheMoocha]

The latest 4WD Action magazine just did a comparison of the difflock vs. traction control.

They both have merits and from the sounds of your requirements you probably don't really need it.

Personally I would have liked to have one but so far the Paj has not let me down yet.

(I wonder how far you would get with TC before it heats up the brakes etc. especially on a large hill climb)

[danc12]

braking

The thing to realise with traction control is that the principle of operation is about applying brakes, which is fine if you are not interested in maintaining momentum with a constant force at the wheels, say in heavy sand or really slippery mud on a hill. Locked rear diff is useful when you want to have a constant push and momentum helps.

Also heavy overuse in slippery situations can lead to overheated brakes, if you are doing a lot of sand work on fraser then it could be a problem.

Dan

[Fudggie]

(I wonder how far you would get with TC before it heats up the brakes etc. especially on a large hill climb)

Its approx 45 secs.

It will start beeping at you first when it is reaching its limit.
The beeps then speed up before the system flat lines (one long constant beep) and shuts down.

When this happens you either have to drive through your brakes if you can keep the momentum going, or wait about 30 sec to let the system cool down.

[matthewfnorbert]

dont think the discs can cool down in 30 sec, maybe the alarm is for the hydraulic pump (which would also be odd..) or fluid temp from the pump..?

[Wilmo]

Also heavy overuse in slippery situations can lead to overheated brakes, if you are doing a lot of sand work on fraser then it could be a problem.
Dan

I've done a lot of sand work in my DID AUTO NS (no diff lock) and the traction control is great, hasn't ever overheated and doesn't prevent the Paj driving out of some pretty 'sticky' situations. Just make sure you turn of the Stability Control though!

[Fudggie]

Besically its the hydraulic fluid getting to hot.
I am told that the following was pulled from a Mitsubishi service manual. It may help explain what is going on.

The ASC responds to driving conditions and controls the braking mechanisms of all four wheels independently by separately applying the brakes for each wheel. It also governs the engine output to manage wheel spin, drift out, and other forces when driving within certain limits.

The ATC system also independently controls the braking mechanisms of the four wheels and it also governs the engine output, but in addition controls the wheel slip ratios to manage accelerations during starting on slippery surfaces. It also improves driving ability on poor surfaces by applying a differential lock effect. So no matter how wet or rugged the conditions become, ATC guarantees the maximum grip off road.

BUT BE WARNED!

This system works well; however, you have a time limit!

The E.C.U. very quickly decides when things are getting too hot to handle. Especially when the Actuator, which is a combination of a Valve relay, a hydraulic brake booster relay, buzzers, a hydraulic unit brake warning lamp, an ABS warning lamp, a 4wd indicator lamp, and a whole heap of other gismos that all start going crazy at once.

Essentially, the hydraulic fluid controlling the brakes, which controls the wheel slip becomes too hot. Once this happens, the hydraulic buzzer sends a signal from the ASTC-ECU to inform you the driver that the Active Control System is overheating. First the buzzing is intermittent, which is warning you to back off. Then once the buzzing becomes continuous, the traction control will completely cut out.

[Eastie]

Simon,
An alternative is to wait and see how the standard tc goes. If unhappy you could get an arb air locker (+compressor) for the front if you decide you need more traction than the tc gives (pro's and cons with just one locker anyhow, so whether it's front or back there's arguments to be had both ways) . I've never been inclined to go stupid on the sand or on muddy inclines that would be difficult enough in the dry so I've never used nor needed one (I had the option of two veicles in stock, one withside/curtain airbags and one with a rear locker - I went the airbags).

When stuck I've always had a winch handy though, so if you don't have or want a winch a diff locker may be a backup strategy that best suits you. Just depends on how good or limited you recon the traction control is and whether you have a winch or recon one locker is enough to get you out of trouble? Decisions decisions

[simonfish]

Thanks everyone for your advise, realistically I won't need a rear diff locker, and as Eastie mentiones, if i decide later that I do want/need one, there is an aftermarket one available.

Now to just find the best deal in Sydney on an NS R DiD, and hand over the cash !!

[Schniff]

I would say that in almost all situations, TC would be superior to Rear locked diff as it works off all four wheels. If you lift a wheel front and rear with TC then the other two wheels will provide forward propulsion. In the same situation with the diff lock you will only have propulsion from one of the rears.
Of course, if you had the ARB front locker engaged as well then this would be superior to TC for traction.

As has been aluded to here by other posts, the real advantage in the locked diff is that it is proactive in preventing wheelspin. It therefore could be advantageous in extreme heavy duty situations where TC will continually overheat. If you are in a situation like that, you probably should think about whether or not you really NEED to be there - and you would probably want an electric winch!

The advantages of TC is that it can be active ALL the time without adverse effects to tyre wear, steering, handling etc and that it will work off all 4 wheels. From my limited experience in the Pajero on sand dunes in the centre, the TC tends to operate when it detects a cross differential slip difference rather than just slip alone. Simply put, I found that TC did not activate when both wheels had a similar amount of slippage, allowing me to maintain momentum. Can anyone confirm that this is correct?