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Axle components - What to upgrade first?


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@FridgeFreezerCorrect, I borrowed a locker for Ladoga. I didn't technically own the car either (my ex girlfriend did don't ask :ph34r:) So I wanted a quick and dirty solution. I fitted a £20 tyre compressor with a switch and pressure gauge from an air lift kit. When we wanted the locker I just ran the pump till the pressure reached something like 30psi then turned it off. When not required anymore I just released the pressure. No tank or fancy soloniods etc.

Mike

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  • 2 weeks later...
  • 2 weeks later...

Persoanlly, I'd drive it. Actually use it. Find out what breaks

I had LSD's on my RRC. Only thing I changed was using some Ashcroft rear half shafts - simply because I was given them. Biggest tyre I used was 32.5". Always muds

On the 100", I broke the one an only diff I've ever broken in a land rover product (except for all the ones we broke at LRE on D2's) - left foot breaking in a gravel stream bed whilst recovering another vehicle, in reverse. So I deserved it

On the 110 and the D1, standard. All the way through - although I used some non standard rear flanges in the 110; which saw more hard off road beating than 99.9% of Land Rovers

My 88" Hybrid (Benji), ran a 4.6 Supercharged JE Lump, yet also didn't break 4.7 series diffs and RRC ten splines, despite 35x12.50 MT's

 

Unless there is a comprehensive design flaw in the vehicle (early D2), it's the driver that breaks the diff. So learn to drive it

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  • 2 weeks later...

That's just crazy though. I can't remember if you had any plans to dyno it, but I think you should!

My transfer box ATB has made little to no difference to the way the car "feels", if that's any kind of a measurement. That's not to say I regret it, I'm just not aware of it.

I think with axle ATBs, the difference has to be more tangible.

...random thought, but does having ATBs front and rear make the centre ATB pointless?

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1 hour ago, ThreePointFive said:

That's just crazy though.

I honestly thought the engine was bogging down/being unhappy, then the smoke from the tyres made its way into the cabin. 

I don't think I need to bother with a 2WD conversion, even if it were entertaining.

1 hour ago, ThreePointFive said:

I can't remember if you had any plans to dyno it, but I think you should!

I didn't have, but I may. It's no fire breather of a 4.0, but probably around the 220-230 mark, most importantly it sounds proper snarly when you rag it.

1 hour ago, ThreePointFive said:

but does having ATBs front and rear make the centre ATB pointless?

Nope, still torque biases between front and rear axles.

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1 hour ago, ThreePointFive said:

...random thought, but does having ATBs front and rear make the centre ATB pointless?

What @Bowie69 said - having ATBs in the middle just means it's less likely the centre will spin freely. An open diff will always split the torque 50:50 between outputs but if one of the outputs has little to no resistance on it then all the power from the input ends up going through to that output. In the instance of open diffs all around then you only need 1 out of the 4 wheels off the ground to lose forward progression, if the centre diff is locked then there's a 50:50 torque and power split so you need one wheel front and rear to lose traction.

If you flip it such that you have an open diff in the centre and two ATBs in each axle then you need to lose traction on one of those axles to lose forward momentum. Depending on the particular ATB then this may be possible with one wheel only but definitely if both wheels lost traction (e.g. jacking up the entire front-end).

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13 hours ago, Bowie69 said:

I honestly thought the engine was bogging down/being unhappy, then the smoke from the tyres made its way into the cabin. 

I don't think I need to bother with a 2WD conversion, even if it were entertaining.

I didn't have, but I may. It's no fire breather of a 4.0, but probably around the 220-230 mark, most importantly it sounds proper snarly when you rag it.

Nope, still torque biases between front and rear axles.

Have you weighed it yet?

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15 hours ago, ThreePointFive said:

 

I think with axle ATBs, the difference has to be more tangible.

...random thought, but does having ATBs front and rear make the centre ATB pointless?

Axle ATBs will have a more pronounce effect than the centre ATB with open axle diffs, but with all three, your vehicle would be significantly more capable on variable surfaces than an otherwise similar vehicle with only axle ATBs.  Not only that, but you have removed a weak point from the LT230 and eliminated a common source of backlash.  With the centre diff locked, your vehicle is currently no different from standard, but for lanes, gravel, winter roads and so on, I’d say you have made a decent improvement, so have not wasted your money.  You just won’t see the full benefit until you fit axle ATBs too.

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14 hours ago, Ed Poore said:

if the centre diff is locked then there's a 50:50 torque and power split so you need one wheel front and rear to lose traction.

That's not entirely correct: an open diff will give a 50/50 torque split but will allow rotation (and thus power) to differ. So axle/wheel with the lowest traction determines the torque that can be applied, with one slipping this will be almost zero.
A locked diff will maintain equal rotation, but will transfer torque (and thus power) to the side that can take the most. So the torque split can be anywhere between 100/0 and 0/100. Which means only one axle needs traction to keep moving and can potentially receive all the torque available.
ATBs are in between, but much closer to a locked diff in terms of possible torque split so almost all of the advantages but none of the disadvantages.

Your explication about wheels losing traction is correct of course, just nitpicking on the physics behind it. 😉

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5 minutes ago, Nonimouse said:

I've never understood the need for a ATB in a center diff, even in racing. The CD has a diff lock. it goes on or off. When you need it, it's there, when you don't it's not.  

It'd be handy on these apparently low-traction tarmac surfaces we have around here :ph34r:.

Actually mostly interested in it being able to stop wheel hop, which is never, ever a good thing.

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43 minutes ago, Nonimouse said:

I've never understood the need for a ATB in a center diff, even in racing. The CD has a diff lock. it goes on or off. When you need it, it's there, when you don't it's not.  

I have read a fair few comments about “grenading” centre diffs with a hanging wheel.  I don’t think a centre diff is wildly beneficial, but I think it’s a nice upgrade if you have the budget.  Not anywhere close to the benefit of axle diff upgrades, though.

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53 minutes ago, Nonimouse said:

I've never understood the need for a ATB in a center diff, even in racing. The CD has a diff lock. it goes on or off. When you need it, it's there, when you don't it's not.  

Well worth it for anything low traction.... otherwise your potentially unloaded front suspension will just make that end more likely to spin and take drive from the rear. 

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I can't speak for the motivations of others but my rationale for a centre ATB was:

1. It would engage automatically if I had missed the cues it was time to use the lever - more applicable to an on-road situation where one might not expect to need it and the reaction time would be minimal

2. I heard they remove slop in the drivetrain and I'm all for improving the driving experience

3. I was going to get it refurbished anyway and the cost was a minimal increase for the potential benefits 

If that makes me a fool then so be it.

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