Freelander 2 (LR2) FL2 Rear Diff Seizure.

GrumpyGel said:

I don't get this - so what happens if the input shaft is not held still (by hand, VCU, Haldex, center diff or simply weight of prop shaft - for example removing the prop on an F1)?

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In these circumstances, referencing the picture in the post above this one, the red carrier and the red crown wheel would drive the orange pinion.

Juzza6720 said:

Is it the orange bit in this pic that you think has seized? That would make sense as the only way the wheels could move would be one forward and one backwards if that's the case?
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Me? Yes I believe the pinion (gold in picture) bearing has seized, as the propshaft forward of the Haldex is free to rotate with the front wheels.

If the pinion isn't turning, the diff carrier/cage (red in picture) can't turn, so the planet gears force the wheel to turn in different directions, which is the symptom I have.

Since my seizing diff drama, I've been looking at the bearing failure issue in detail.
It appears to me to be a design flaw.
Looking at loads of pictures, it seems there's no direct way for lubricating oil to get to the pinion outer bearing. Oil can only get to the outer bearing, after its passed through the pinion inner bearing.
This is silly, as whenever the pinion is spinning, oil will naturally migrate away from the outer bearing, due to the taper of the rolling elements.

I have never seen a differential where there's no direct route for oil to get to the outer bearing, which is why this design seems flawed to me.

If the bearing can't get a good supply of lubricant, then it'll run hot, which leads to premature wear.

This lube issue seems a logical primary cause to me, as the pinion inner bearing doesn't suffer any wear at all, and isn't replaced as part of the LR diff repair process.

I've been reading that the later diffs with the larger bearing also suffer bearing failure, which again points to the lack of lubrication, as the larger bearing has a much higher load capacity than the smaller early bearing.

I personally think the bearing installation pre-load is too high, which would cause excessive loading on the bearing rollers, which again would shorten the smaller bearing life.

I know that some of the tratter boys deliberately nick the mating face on axle tube to wheel bearing (or am I hayvering and it was front swivels?) section of the axle to allow axle oil in to lubricate the bearings/swivel (whichever it was) - could you do something similar with a die grinder? ie: Notch a little channel into the diff casing to allow oil past the inner bearing to get to the outer one?

Jayridium said:

Notch a little channel into the diff casing to allow oil past the inner bearing to get to the outer one?

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Normally oil is flung towards the outer pinion bearing off the crown wheel by centrifugal action. The diff casing is deliberately shaped to allow the oil to be flung towards the pinion outer bearing.

Here's a picture of the FL1 rear diff, with its distinct oil passage "hump" clearly visible. I've marked the route that oil will take, straight to the pinion bearings.


This cast in oil passage will ensure that both diff pinion bearings are bathed in copious amounts of lubricating oil.

I struggle to see how any design that doesn't allow plenty of oil to the bearings could even be considered acceptable.

Have you seen The LR tsb regarding this problem nodge... from what I can make out, it's suggesting the haldex is coming on at the wrong times...effectively acting like a VCU would..and binding up the transmission, Software mod to alter it's characteristic etc....
Or is this yet another problem.

Nodge68 said:

The Haldex is just the same as a VCU, only instead of plates surrounded by a fluid that thickens with agitation, the Haldex has a stack of clutch plates, not dissimilar to a motorcycle clutch, which are actuated by a pump and cylinder.

When driving down the road, and the Haldex isn't providing drive, everything rotates together, just is it would on a VCU equipped FL1.

I can turn a front wheel, and this turns the propshaft, so the Haldex isn't stuck, and if it were, it would be no different to a seized VCU. I seized VCU doesn't stop the rear wheels on a FL1 from turning, same as a stuck Haldex wouldn't on a FL2.

This issue must be in the diff pinion, where it's taking drive from the Haldex.

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Actually that's not correct.
The haldex is filled with thin oil and has a small electric pump in there, when running normally the rear axle freewheels and drive is done by the front wheels only, when required the pump pressurises the center of the haldex which is like a hydraulic cylinder and compresses the steel plates together, which then transmits the drive to the rear diff, and you have four wheel drive.
The diff pinion bearings pack up and this is well documented, and they can be repaired, but take care because if you damage the gears then you are into a new world of finding a new diff.
I had to do mine last year, I took out the diff and had it rebuilt, at the same time I drilled the bottom of the casing and tapped the hole then added a magnetic plug so that I can now change the diff oil and check the plug for metallic bits.
I will try and find a picture.

Found it

jedi said:

Have you seen The LR tsb regarding this problem nodge... from what I can make out, it's suggesting the haldex is coming on at the wrong times...effectively acting like a VCU would..and binding up the transmission, Software mod to alter it's characteristic etc....
Or is this yet another problem.

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There is a software change (mine is on the latest), which reduces the Haldex activity a bit when maneuvering. However it does still activate as it can be felt when pulling away. This is done to ensure there's minimal slipping when moving away from rest.

I don't believe this bearing issue is anything to do with the Haldex anyway, as the wrong bearing is failing. The bearing that fails is only supporting the Haldex clutch pack, but the larger inner bearing is taking the drive loads, and it doesn't fail.

It's because of this, that I'm doubtful that the Haldex is the cause.

raywin said:

Actually that's not correct.

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What's not correct?

Nodge68 said:

There is a software change (mine is on the latest), which reduces the Haldex activity a bit when maneuvering. However it does still activate as it can be felt when pulling away. This is done to ensure there's minimal slipping when moving away from rest.

I don't believe this bearing issue is anything to do with the Haldex anyway, as the wrong bearing is failing. The bearing that fails is only supporting the Haldex clutch pack, but the larger inner bearing is taking the drive loads, and it doesn't fail.

It's because of this, that I'm doubtful that the Haldex is the cause.

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Actually I've just read from gen 3 upwards the haldex is preactive..ie it turns on a bit when no slip is detected.This is to give a more 4x4 feeling, where as the gen 1 and 2 are proactive, ie turns on after slip is detected....So seems about right..

What's this bigger pinion bearing bell engineering are installing? Are they milling out the casing and installing a physically bigger bearing?

Also is there no oil drain plug on the FL2 diff?

jedi said:

Actually I've just read from gen 3 upwards the haldex is preactive..ie it turns on a bit when no slip is detected.This is to give a more 4x4 feeling, where as the gen 1 and 2 are proactive, ie turns on after slip is detected....So seems about right..

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The LR engineers must have done some tweeks to the standard Haldex software, perhaps to better suit the off road ability of the LR brand.
I can or could definitely feel the drive being transferred to the rear when pulling out of junctions, as the steering slightly tightened, like if the diff lock has be engaged on a more traditional 4X4.

jedi said:

What's this bigger pinion bearing bell engineering are installing? Are they milling out the casing and installing a physically bigger bearing?

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I believe so, but I've read that the later larger bearings also fail, which means the bearing capacity is the problem.

jedi said:

Also is there no oil drain plug on the FL2 diff?

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That's correct, although there is a flat on the bottom of the casing, where it can be fitted. Unfortunately the diff casing has an island above this flat, so an amount of oil and sludge will remain inside the diff, if a plug is fitted.

Blimey so there's no way to change the diff oil? Is there a top up hole?

Not knowing anything about the FL2 transmission, apart from what I've read above!! The only thing that bothers me is whether a bearing could seize enough to stop a car, then after you worked on the brakes unseize and then seize again.

From my experience it doesn't fit with the way bearings fail, but happy to be corrected. Anything else that could lock it up, release, then lock up again???

jedi said:

Blimey so there's no way to change the diff oil? Is there a top up hole?

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No drain hole in the diff, no. But the FL1 doesn't have a rear diff drain either.
There's no drain on any components of the FL2 drive train except for the gearbox.

andyfreelandy said:

Not knowing anything about the FL2 transmission, apart from what I've read above!! The only thing that bothers me is whether a bearing could seize enough to stop a car, then after you worked on the brakes unseize and then seize again.

From my experience it doesn't fit with the way bearings fail, but happy to be corrected. Anything else that could lock it up, release, then lock up again???

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I thought along those line Andy.

However when the diff first locked, it freed off as the car was being pulled up the ramp backwards. I believe this was partly due to going backwards, but also because the bearing had cooled down as 45 minutes had passed, between stopping and being winched backwards.

Stupid me just figured the brake had cooled down, which is why it freed off.

After I fitted the rear brakes, I drove down the road and instantly noticed the rear diff was much much louder that it had been. Unfortunately it locked up so quickly after I'd pulled away, that I had absolutely no time to do anything sensible, before I was slipping and sliding down the road.

I believe the diff bearing has disintegrated and friction welded it's self up, which is why it now won't move at all.

I'm hoping it's not done any serious damage to the shaft or the differential itself, or to the casing, as I'd need to replace it, which would put me over budget, and out of pocket.

Nodge68 said:

What's not correct?

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The haldex is just the same as the VCU
The VCU drives continuously but can slip the haldex freewheels until the ECU pulls in the clutch.
One of the reasons put forward for the diff failurs is the way the ECU applies the torque, apparently later software modifies this.

jedi said:

Blimey so there's no way to change the diff oil? Is there a top up hole?

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Yes through the Top up hole, i used an electric pump to remove the oil, and an hand pump to add new oil.
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hand pump to add fresh oil.
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Found a FL2 diff rebuild 'how to' in LRO Guide to Freelander.

If you haven't seen it or want a copy I'll scan and post or email it.

So I plan on getting the diff out this weekend. I've had a look at the diff, and it appears to be undamaged, on the outside at least.
I've ordered the Haldex service stuff, which was cheaper than I was expecting, as my FL2 pleasingly has a Haldex Gen 4 fitted, which is good.

I'm not going to order the diff repair kit yet, as I wanted to make sure the diff isn't beyond repair first.

If it's repairable, I'll be replacing the bearing/s with Timken, as I don't want to be doing it again any time soon.

I do believe that there is a design issue with these diffs, so I might change the oil annually, simply to provide the bearings with the best lubrication possible. To make this task easier, I'm going to install a diff drain plug, which I feel is a worthwhile addition.

I have the diff tools, so once it's out the vehicle, I can pull it apart, and carry out the repair assessment.

More to follow.

Hi John.
Please take a few photos if you have time during removal and repairing, i am following this thread with great interest, good luck Arctic.