Rear Diff problem ?

Hello, I'm looking for some advice please.

I've got a 2001 Freelander 1, the 1.8SE petrol version. Its got 75k miles on it. I bought it as a non runner because the timing belt had snapped, and ended up repairing that and replacing the head gasket. All good, runs really well now. But, once up and running I noted the transmission was tightening up a lot when reversing around a corner on full lock. I did enough forum searches to frighten myself into disconnecting the propshaft and ordered up a VCU from Bell Engineering. Disconnecting the prop made the problem go away. Whilst the prop was off I noted the rear diff whined from 30 - 50 mph, so replaced the oil in that and replaced the gearbox (manual) oil and IRD oil at the same time. Anyway, VCU arrived from Bell and I fitted it. According to Bell, the oil in the one I'd exchanged had thickened, but it was not as bad as most they see. I reversed out of the drive - and it was still really tight on full lock, with I can best describe as a "graunch" coming from the rear.
When we had the snow/frosty conditions, I reversed out of a parking space, on full lock, and as expected everything tightened up - then outer rear wheel "skipped" on the slippy surface and the tightness went away. I continued to reverse and it tightened up again, the same wheel (on the outside) skipped again.
So to me, this seems like a rear diff problem ? Its like the rear wheels will not go at different speeds when going round a corner.
Every where I've searched relates the tightness reversing around a corner to a knacked VCU. But mine has been replaced and its still bad, with the outer rear wheel skipping if the surface is slippery. Is there anything else that could be the culprit ? Driving in a straight line everything is fine, just a whine from the diff at about 40mph now the prop is connected.

To check the rear diff turns freely:

Lift both rear wheels and turn 1. The other rear wheel will turn in the opposite direction.
Now lift both wheels on one side. Put gearbox in neutral and turn one lifted wheel and the other lifted wheel will turn in the same direction.

The above works with the props/vcu fitted. If any of these are off then only lift the rear wheels. Turning the rear wheels and the front connection on the rear diff will allow you to check the diff is turning inside.

Thanks Hippo, I will give that a go once my sickly SAAB is out of the workshop.

Is there a simple way to check the condition of the rear CV joints ? I did wonder if they were binding somehow.

Hi, mine whined when I brought it, it was the rear diff bearings, also needed rear diff support brackets, have you checked your brakes, if the pad has seperated from the metal it can be ok going forward but locks up in reverse, had that fault on a horsebox trailer once

lol, I've never seen a noob come in with such a perfect description of Freelander transmission

A rear wheel skipping on a low-grip surface such as snow is to be expected on Freelander. Your diff whining means you may be in need of a replacement/reconditioned unit - but it will not be causing the tightness in reverse or wheel skipping you describe.

As you know, Freelander does not have a center diff that allows the front & rear axles to rotate at different speeds - the front axle is geared directly to the gearbox and there's a direct 1:1 drive to the back axle. To allow then to rotate at different speeds - it has the VCU splitting the prop going to the back axle. The VCU allows slippage at low speed differences between the axle (eg reversing on full lock) but firms up when the differences become higher (ie front wheels lose grip).

However, it always does put quite a grip between the props even at small differences in axle speed - so there will be some wind up - just not enough to damage anything. When your on tarmac the grip the wheel offers is greater than the grip given by the VCU - so the VCU slips. When your on snow or gravel (etc) the grip the wheel offers is less than the VCU - so the wheel skips.

What I'd also say though is that although you may feel some 'braking effect' when reversing on full lock with a 'healthy' Freelander should not give too much.

So, even though your VCU is new - I would check it out. Have a look at the 1 wheel up test on here and give it a go - see what times you get.

Also check your tyres out - make sure they are all the same make/model/spec and they are all pumped to the same pressure.

Its a high probability that previous problems with the VCU and/or tyres has caused your rear diff to wear and if that's the case, there will probably also be wear to the IRD. What colour was the oil that came out of the diff & IRD? Did it look greyish/metalicy?

Thanks for your replies folks.

I did indeed strip and check the rear brakes - I thought a shoe might be lifting in reverse - but everything was in good order.

The oil that came out of the diff was almost black. Because of the whining I have picked up a reconditioned rear diff, just not fitted it yet.

The IRD oil was indeed grey/metallic. But I've not noted any other issues with the IRD - no noises, clonks etc. And the graunch I mentioned when reversing on full lock comes from the rear end, from whichever rear wheel is on the widest arc of the turn.

From what I've read, VCU issues cause the taper bearing on the output shaft of the IRD to wear. Can the bearing be replaced "in situ" whilst I've got the prop off doing the rear diff, or does the box need to come out ?

In the meantime I've made a point to try not to get the Freelander into any situations that need reversing out of on more than half lock !

Our Freelander had little braking effect in reverse on lock and I think was reasonably 'healthy'. Our drive is part concrete block and part gravel. Even though we felt little braking effect, as we turn off the blocks onto the gravel a rear wheel would skip - forwards or backwards.

Our transmission collapsed due to an under inflated tyre. I thought something was 'not right' with the car, but didn't put 1 and 1 together to realise it was a tyre that needed pumping. While we were driving I noticed a rattle develop at the back of the car and thought it was the exhaust, then about a mile later my IRD went bang BIG time. I had to get the car lifted home, even if you pushed the car every meter, or so, there was a huge bang.

In my case the crown/pinion gear teeth were damaged in the IRD. On test driving with the props disconnected there was a slight noise coming from the front transmission, so I had a bearing repair kit shipped over and had a shop pull/push them. As the gears were gone, I also had the shop remove the pinion gear and unfortunately its now 2wd, although its still carrying props etc.

As your IRD is not banging big time, I imagine your crown/pinion gears are not to far gone. Replacing all 8 bearings is probably the safest way to go, but I'd have thought just replacing the bearing(s) on the pinion would put back 90% of any life that's been ground out of it As the oil was grey/metallicy - I imagine you should do something.

I would be worried about the braking effect your getting. Bells will tell you that the 1 wheel up test is not a good indication of the VCU's health - take that with a big pinch of 'commercial interest' salt. I would do it and compare your results to others on here. Recon VCUs have been shipped either 'to open' or 'to tight'. Having incorrect tyre sizes/pressures is a problem for Freelander - but mainly on the open road at speed - on slow speed manouvering wheels will rotate at differing speeds anyway - but it won't help if the tyres are not right.

I'd also maybe have a drive of another Freelander to get a comparison or get another Freelander driver to check yours out see if they think its braking too much.

Incidentally I'm still happy I made the right decision rebuilding as 2wd. I can't take it places I used to - but I could not find anywhere here selling reconed parts here - the cheapest I could find from NZ suppliers was almost £4K. Getting VCUs and heavy gears or a whole IRD shipped from the UK was hugely expensive, so the old girl was rebuilt 2wd. Its been fine for 2 years and served us proud still taking us to great places

Got the sickly SAAB sorted yesterday so had the Freelander in the workshop today. Did the diff test as suggested above, nice and smooth, no rumbling or binding.
Jacked one rear wheel up and stuck a torque wrench on a wheel nut to see if it turned. Yes, with some pressure I could turn it very slowly. Not sure what I was expecting to see, but when I did this and peered underneath I could see the front of the diff waggling about ! I'd bought a new front diff mount/bush when I got the VCU so decided to fit it. Ended up lowering the rear subframe by 1/4 - 1/3 inch to waggle the old mounting out without taking the diff out.
The rubber mount was only just about holding together. With the new one fitted and everything back together, it all feels better at the back end. Reversing round a corner on full lock is still "tight" but - and it may be my imagination - not as tight as it was. Feels smooth, no graunching noise now, just a click from the rear end that sounds like a bush moving in a mount. Clicks again when you go forwards and then is silent.
I have different make tyres on the front to the rear, but with the car on level ground, tyres at proper pressure, I have checked the height (using a contraption based on a 1m rule and a square with a spirit level) of front v rear and its 2mm different, so I'm happy with that.
I will pick up a pinion bearing kit for the IRD and get that fitted when its off the road having the new rear diff fitted.
Thanks for all the help, information and support. It may only be my little run about, but it does everything I want it to do and I'd like to keep it healthy !

Whistler said:

I have different make tyres on the front to the rear, but with the car on level ground, tyres at proper pressure, I have checked the height (using a contraption based on a 1m rule and a square with a spirit level) of front v rear and its 2mm different, so I'm happy with that.

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"...so I'm happy with that." I wouldn't be!
There's plenty of info' on this forum about the potential problems with mismatched tyres contributing to IRD and diff destruction! I'd recommend you look into this carefully and draw on other contributors experience. A lot of it was 'earnt' at great expen$e.