Freelander 2 (LR2) FL2 Rear Diff Seizure.

I've decided to do a dedicated thread on the on going issue with my FL2 project.

The engine is not perfect, but it's perfectly driveable, so that's what I've been doing.

However a new issue has come up, with rather scary symptoms.

The rear diff was noisy from the day I bought the car, although over the last 100 miles or so, it had got more noisy.

Knowing these diffs go noisy, I decided to put off any remedial action until next year, when the weather is more favourable.

However the diff has had different ideas on this time frame.

Last week I suffered a wheel locking at 40, resulting in being taken home on a flad bed, and me blaming the parking brake for the seizure, as they were absolutely shot.

However on the test drive after replacing the whole rear brakes, the rear wheels locked again, even worse than the last time.

On moving the vehicle under its own power and the recovery lorry winch, its evident that the rear wheels are trying to rotate in different directions.

This leads me to believe that the diff pinion bearings have seized, preventing the diff carrier from rotating, giving the symptoms it now has.

I'll take the diff out over the Christmas break for a look, and possibly repair it.

In the meantime.
I issue a warning to FL2 owners, that rear diff noise could very well result in sudden diff seizure.
This means the vehicle is very difficult to control, as the rear wheels try to turn in opposite directions.

I was luck, twice. But luck can always run out.

Be warned!!

Sounds like a design failure worthy of recall and correction to me.

I always have a small stock of FL 1s for sale!!!

Have you lifted the rear wheels and given them a spin to see if they will turn? What's the drive like from the prop to one wheel, then the other?

andyfreelandy said:

Sounds like a design failure worthy of recall and correction to me.

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andyfreelandy said:

I always have a small stock of FL 1s for sale!!!

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Hippo said:

Have you lifted the rear wheels and given them a spin to see if they will turn? What's the drive like from the prop to one wheel, then the other?

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Lifting one rear wheel off the ground I can only turn it a few it a few degrees each direction, before it stops turning.

Lifting both wheels off the floor, results in the wheels turning in opposite directions.

you're going through the ringer with this one.

Kudos to the dedication i'd of crushed it..

Nodge68 said:

Lifting both wheels off the floor, results in the wheels turning in opposite directions.

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If there was drag on the Haldex, would this not be the expected behavior?

I wonder if what you've experienced could explain the couple of situations where people have lost control of their F2s at times when they should not be anywhere near losing control.

GrumpyGel said:

If there was drag on the Haldex, would this not be the expected behavior?

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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.

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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Sure it is probably the diff itself - they are know to be very problematic.

You compare the Haldex to the VCU. If the front wheels were on the ground on an F1, if you turned a back wheel, the other would rotate in the opposite direction because of the VCU drag. If there is some drag in the Haldex as well (either in design or need for maintenance), the same will presumably happen.

Excuse my ignorance on diff's, never done one before but don't the rear wheels turn in opposite directions when one is turned by hand and both rear wheels are jacked off the ground?

GrumpyGel said:

Sure it is probably the diff itself - they are know to be very problematic.

You compare the Haldex to the VCU. If the front wheels were on the ground on an F1, if you turned a back wheel, the other would rotate in the opposite direction because of the VCU drag. If there is some drag in the Haldex as well (either in design or need for maintenance), the same will presumably happen.

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Yes but think about it - it wouldn't cause a sieze-up would it - just like Nodge says - similar behavior to a tight VCU

potus said:

Excuse my ignorance on diff's, never done one before but don't the rear wheels turn in opposite directions when one is turned by hand and both rear wheels are jacked off the ground?

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There are 3 "input/output ports" on a diff - the 2 wheels and the prop shaft. If you turn 1 back wheel, you will get a response on 1 of the others - the one with least resistance. The weight of the wheel is a resistance, so it depends on the resistance on the prop "port". The Haldex is bolted directly to the diff, so if it is truly "open" then there is basically no resistance there and that "port" will turn. However, if there is any drag on the Haldex it will be greater than that of the other wheel, so the wheel will turn and in the opposite direction to the wheel you are turning.

dfossil said:

Yes but think about it - it wouldn't cause a sieze-up would it - just like Nodge says - similar behavior to a tight VCU

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That is true, but I don't think turning 1 wheel and the other turning in the opposite direction confirms this (seized diff) as there are other possible (likely) reasons for that.

Could be a broken tooth between crown wheel and pinion, or seized crown wheel bearings, planetary gears inside the diff carrier are unaffected

If it was an F1, you could undo the 4 bolts holding the prop shaft to the diff flange. If all was OK, turning a wheel would result in the flange turning - if it didn't then the diff is broken. Refitting the prop would result in the other wheel turning.

Lot more difficult to do the same tests with a Haldex complicating matters.

GrumpyGel said:

You compare the Haldex to the VCU. If the front wheels were on the ground on an F1, if you turned a back wheel, the other would rotate in the opposite direction because of the VCU drag.

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The FL1's VCU causes much more drag on the diff input flange, than the Haldex does, when it's not engaged. However the drag on the input isn't the reason the wheels turn in different directions. The wheel turn in different directions because that's what the differential does. If the input shaft is turned in one direction, both wheels will turn equally, as long as they have the same drag. If one wheel is slowed down, the opposite will speed up by the same proportion. If the input shaft is held still sufficiently hard so it doesn't turn, and a wheel is turned in a forwards direction, then the other side must turn in the other direction at the same speed, as the rotational difference between the sides must remain constant.

GrumpyGel said:

If there is some drag in the Haldex as well (either in design or need for maintenance), the same will presumably happen.

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Nothing I said above has any relationship to the VCU, Haldex or any other means of drive control.
That's simple the medium for switching in and out the drive to the rear.

potus said:

Excuse my ignorance on diff's, never done one before but don't the rear wheels turn in opposite directions when one is turned by hand and both rear wheels are jacked off the ground?

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Yes that's correct, as long as the diff carrier isn't turning, the planet gears reverse the rotation of the axle shafts.
This is the situation I'm currently in, so I'm guessing the input bearings have broken up and locked the diff input pinion. This is holding the diff carrier or cage still, so my wheels are turning in different directions.
Which isn't very pleasant, when driving as any speed.

freelance said:

Could be a broken tooth between crown wheel and pinion, or seized crown wheel bearings, planetary gears inside the diff carrier are unaffected

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I'm going with seized pinion bearings, as those are known week point on these soft cheese diffs.

Nodge68 said:

If the input shaft is held still sufficiently hard so it doesn't turn, and a wheel is turned in a forwards direction, then the other side must turn in the other direction at the same speed

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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)?

Looks like Bell engineering are all ready all over this FL2 diff.... and if this is the case, should LR not recall these potentionally deadly rear diffs???

http://www.bellengineering.co.uk/freelander-2-products/

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?