Diff locks (operation)

[DenisM]

I am wondering if I will miss the Detroit TrueTrac in the rear differential of my Rebel. It is a gear driven (TorSen) limited slip (not the standard clutch style) which never lets me get stuck and is "automatic" when there is a difference in the torque driving one rear wheel from another. It is seamless and requires no driver button pushing. I wonder could such a TorSen differential be installed in the rear of the Grenadier so there is an option other than "fully locked or fully open"? I think the military HUMVEES used these differentials front and rear.

The axles and diffs are bespoke for the Grenadier... however, anything is possible I guess in this regard.. just depends on how deep are your pockets and your motivation

 

[cjsmith]

The axles and diffs are bespoke for the Grenadier... however, anything is possible I guess in this regard.. just depends on how deep are your pockets and your motivation

Of course you are right. It took Detroit/Eaton 6-7 years of the Rebel on the road before they made the TrueTrac for the RAM axles and there are a lot more RAMs out there than there will ever be Grenadiers. But they made their eLockers for the Grenadier so maybe...

 

[Tom109]

There is a subset people in USA that bought the Grenadier without the lockers. Their argument, which makes total sense, they never got caught in situation that they need them. Many of vehicles they reference had really good TC. It will be interesting to get their feedback as they get in woods with theirs.

IMO, the Gren is not the vehicle to skip the lockers, period.

I am wondering if I will miss the Detroit TrueTrac in the rear differential of my Rebel. It is a gear driven (TorSen) limited slip (not the standard clutch style) which never lets me get stuck and is "automatic"

A great differential, and really good on-road in poor/deteriorating conditions. It could have been a good option for those that will never push the Grenadier’s capability. Short detour, then right back to always order the factory lockers.

 

[255/85]

I am wondering if I will miss the Detroit TrueTrac in the rear differential of my Rebel. It is a gear driven (TorSen) limited slip (not the standard clutch style) which never lets me get stuck and is "automatic" when there is a difference in the torque driving one rear wheel from another. It is seamless and requires no driver button pushing. I wonder could such a TorSen differential be installed in the rear of the Grenadier so there is an option other than "fully locked or fully open"? I think the military HUMVEES used these differentials front and rear.

Eaton says front and rear Truetracs can be run on road without any real issues in a full-time four wheel drive as long as the transfer case is unlocked. Kind of like a mechanical traction control system - good enough for our uses TBH.

I think the Torsens in HMMWVs are a bit different from helical lockers like Truetracs albeit based on a similar principle. Torsens aren't known for their strength in smaller diffs.

 

[PBD]

Just a quick update on my situation. I was contacted by ineos on 13/12 who are to orange vehicle to be taken back for checking, radio silence since.
28/12 needed to use diff locks and low gear (I have new transfer box and yes the "collar pin" is still in place)
What an adventure! Center diff lock selection was easy, low gear was a nightmare even when the instruments said it was in low, still in neutral, anyway it eventually went in with help from my passenger!
Next up rear the front lockers. Well all the lights came on to say the were engaged but we were both sure they were not! reverse procedure and they all went out.
After obstacles it would not come out of low gear no matter what we did, including engine off and on, forward & back etc, etc. Drove it back off road to barns and it took me with two hands, my mate in back seat pushing for all he was worth to get it out of low gear, high gear no problems. One wag pointed out that not only is the Grenadier built like a tank, it also takes three men to drive it
Yes we followed instructions to letter.
I must be mad, I still love it to bits, just got a Friday afternoon car!

 

[Logsplitter]

Just a quick update on my situation. I was contacted by ineos on 13/12 who are to orange vehicle to be taken back for checking, radio silence since.
28/12 needed to use diff locks and low gear (I have new transfer box and yes the "collar pin" is still in place)
What an adventure! Center diff lock selection was easy, low gear was a nightmare even when the instruments said it was in low, still in neutral, anyway it eventually went in with help from my passenger!
Next up rear the front lockers. Well all the lights came on to say the were engaged but we were both sure they were not! reverse procedure and they all went out.
After obstacles it would not come out of low gear no matter what we did, including engine off and on, forward & back etc, etc. Drove it back off road to barns and it took me with two hands, my mate in back seat pushing for all he was worth to get it out of low gear, high gear no problems. One wag pointed out that not only is the Grenadier built like a tank, it also takes three men to drive it
Yes we followed instructions to letter.
I must be mad, I still love it to bits, just got a Friday afternoon car!

I wonder if the Bowden cable that links the gear shift/diff lock lever to the transfer box is the problem . I’m told that was the cause of the problem on my vehicle. Possibly clamped up too tight during manufacturing

 

[Tinerfeño]

Eaton says front and rear Truetracs can be run on road without any real issues in a full-time four wheel drive as long as the transfer case is unlocked. Kind of like a mechanical traction control system - good enough for our uses TBH.

I think the Torsens in HMMWVs are a bit different from helical lockers like Truetracs albeit based on a similar principle. Torsens aren't known for their strength in smaller diffs.

They are basically open differentials so there is no problem whatsoever on-road. Many manufactures, at least Eaton, Quaife, Ashcroft, and possibly many more.

To what you refer with "smaller diffs"? in Rover axles they seem to be bullet proof. Eatons Detroit Lockers are not ...

And concerning the use of Torsen diffs on Ineos I would like to have it on front axle. It's a perfect device there as it doesn't harm steering. Also inside center differential it would make sense (no need to use CDL on easy off-road conditions). And traction control would be available.

 

[PBD]

I wonder if the Bowden cable that links the gear shift/diff lock lever to the transfer box is the problem . I’m told that was the cause of the problem on my vehicle. Possibly clamped up too tight during manufacturing

I don't know mate, just leaving it in road mode and using it as little as possible for now. Hope the trip is going well.
DCPU if you read this WELCOME BACK

 

[cjsmith]

They are basically open differentials so there is no problem whatsoever on-road. Many manufactures, at least Eaton, Quaife, Ashcroft, and possibly many more.

To what you refer with "smaller diffs"? in Rover axles they seem to be bullet proof. Eatons Detroit Lockers are not ...

And concerning the use of Torsen diffs on Ineos I would like to have it on front axle. It's a perfect device there as it doesn't harm steering. Also inside center differential it would make sense (no need to use CDL on easy off-road conditions). And traction control would be available.

My thinking too!

 

[globalgregors]

I would advocate for engaging the center diff lock as soon as you go off a paved surface. As you've illustrated, an open center differential is a detriment off road.

Yes, this is also my practice with the Gren.

In rural areas here in Oz it is common to find oneself driving at highway speeds on unsealed roads.
Not mentioned here is the different behaviour of the on-road versus off-road ESC, which is particularly noticeable at speed.

The on-road setting produces, at least by my assessment, exagerrated interventions when the vehicle moves around in the way one would expect over an uneven surface at speed.

The off-road ESC mode appears to permit somewhat more movement and ultimately a more stable ride.

For me this is reason enough to engage CDL whenever one is on a low traction surface.
I have only limited winter driving experience but for US owners this may be a point of consideration.

Otherwise the whole roller question is somewhat rarefied: this is a vehicle that does not tend to get stuck.

 

[Tinerfeño]

For me this is reason enough to engage CDL whenever one is on a low traction surface.
I have only limited winter driving experience but for US owners this may be a point of consideration.

I also do engage CDL always when on low traction surface. And low gear if it is rough. But I don't engage CDL immedietely when there is snow or ice, it depends. When traction gets worse (usually around 0°C) or snow deeper I lock it. But I don't have ESC or TC on my cars so the behaviour doesn't change so much (just a little more understeer) so with IG I would first do some testing and push it into the limits on a safe place to see what happens. Then you won't get surprised later ...

 

[255/85]

They are basically open differentials so there is no problem whatsoever on-road. Many manufactures, at least Eaton, Quaife, Ashcroft, and possibly many more.

Yes, there are a few more manufacturers of this type of differential locker out there - including some I would prefer above the others - but only based on design and not my experience with them. I spoke to a few different customer service departments trying to judge if there was any interest in producing Grenadier compatible lockers anytime in the near future but received little more than a polite "No. Not at this time.". Hence our ordering of the factory F/R lockers for our SW.

To what you refer with "smaller diffs"? in Rover axles they seem to be bullet proof.

I have been told numerous times by people much more experienced than I am to be wary of small Torsen locking differentials. The decreasing radius of the perpendicularly aligned worm gears leaves an increasingly reduced contact tooth surface and, more importantly, the correspondingly smaller spur gear tooth just runs out of reliable strength and contact surface. At what point (i.e. - ring gear size) and on which models I don't know. Surely there is little issue with true Torsens as found in US HMMWVs. Nonetheless, I'm sometimes forced to trust in other's expertise.This problem is much less prevalent (or maybe doesn't exist at all?) on longitudinally aligned torque-biasing versions like Truetracs, etc. afaik. I know nothing about Land Rover components.

Eatons Detroit Lockers are not ...

Ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha ha...
Don't do that! You made me laugh so hard that milk came out of my nose!

And concerning the use of Torsen diffs on Ineos I would like to have it on front axle. It's a perfect device there as it doesn't harm steering. Also inside center differential it would make sense (no need to use CDL on easy off-road conditions). And traction control would be available.

If I'm honest I would be fine with them in the Grenadier both front and rear. As I'm not about to tackle any of the difficult venues (Hammers, Rubicon, etc.) here in the US, I have little interest in on/off open-to-spool lockers. In the transfer case with locking potential a Truetrac makes perfect sense too - and no electrics to deal with. I hadn't even considered the ESC/TC function. I was just figuring on a little left foot braking now and then.

 

[nuclearbeef]

To answer the original, original question; the diff locks disengage ASAP but the light will not show disengagement until the vehicle travels far enough for the wheel speed sensors to register different speed of rotation of the wheels.
This may be for axles only, not center diff.

 

[Oskar]

To answer the original, original question; the diff locks disengage ASAP but the light will not show disengagement until the vehicle travels far enough for the wheel speed sensors to register different speed of rotation of the wheels.
This may be for axles only, not center diff.

This is probably the most essential fact that most people who complain don't get right. Technically it is the right design from my perspective. However it is obvious that it is not made for everyone. Showing an disengage status without validations seems wrong.

 

[255/85]

To answer the original, original question; the diff locks disengage ASAP but the light will not show disengagement until the vehicle travels far enough for the wheel speed sensors to register different speed of rotation of the wheels.
This may be for axles only, not center diff.

The new TFL video comparison of an older Toyota 80 series and a Grenadier illustrates that aspect pretty well. (The IG belongs to a forum member if I'm not mistaken.) The lockers appear to engage immediately. When the lockers are disengaged it takes a bit of time and some distance. It's not expressly clear whether they're waiting for the lights to go out or for the locking diffs to return to open status.

Grenadier vs 80 Series <-- Link

 

[[ Adam ]]

The new TFL video comparison of an older Toyota 80 series and a Grenadier illustrates that aspect pretty well. (The IG belongs to a forum member if I'm not mistaken.) The lockers appear to engage immediately. When the lockers are disengaged it takes a bit of time and some distance. t's not expressly clear whether they're waiting for the lights to go out or for the locking diffs to return to open status.

Grenadier vs 80 Series <-- Link

I was waiting for the lights to go out.

Admittedly - that was my first time engaging the lockers.

 

[DenisM]

The lockers disengage in about half a turn of the wheel but the sensors take longer to register....

 

[j3t3r]

1 & 2 above, I would say the Gren center diff should be locked to equate to the jeep system.

Observation - If you were going to be on-wheeled in the jeep, you shift to 4wd. If you’re going to be one-wheeled in the Gren, you just lock the center diff (which is simpler operation and possible at speed).

All I can tell you is in 27 years of driving them, I have never been one-wheel-stranded in a D1 or RRC. Yes, fancy ETC systems are like behind the scenes magic, but do have their limitations. While the Gren system requires driver intervention (throw a lever, push a button) it is mechanical and will work as long as you have fuel.

Can you really lock the center dif at speed? I thought neutral had to be engaged first (obviously can still be rolling in neutral)

 

[Tazzieman]

Can you really lock the center dif at speed? I thought neutral had to be engaged first (obviously can still be rolling in neutral)

Just whack it in. I'm often going from bitumen to dirt and back , you don't need to stop. It's old school.

 

[Mountain4x4]

Automatic lockers are for mild use. They lock and unlock at will, they are not ideal. In the case of the GM G80 almost useless. Manual lockers are next level. Want top level? The Power Wagon has a rear manual locker that acts as an LSD when off.