Ok, so I bought a 2002 Freelander TD4 and she ran ok, but I knew I would have to replace the VDU at some point. It finally started getting real bad, knocking while turning, so I ordered the VDU from Bell. That evening leaving work I get a couple bangs and jerks, so I stop and take a look. Don't see anything, but I figured the VDU had failed and was the culprit. I left it at work and came in the next morning and removed the whole prop shaft to get ready to change the VDU(still trying to get the front shaft off the VDU). I hop in and start to back up and I still have the jerking and banging, seems like front left side, with the prop and VDU removed...very frustrating.

Anyone here more familiar with the drivetrain, give me a little guidance on how I can figure out which is causing the issue? The trans is in neutral, but I can not turn the output of the IRD by hand...not sure if I should be able to.

Thanks!

Also...the black oil/grease that oozed out of the front prop shaft front connection joint to the IRD...it smells like RTV silicone...should I just repack this, or is there something I should change while the propshaft is out?

stholt5233 said:

Ok, so I bought a 2002 Freelander TD4 and she ran ok, but I knew I would have to replace the VDU at some point. It finally started getting real bad, knocking while turning, so I ordered the VDU from Bell.

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You mean the VCU (Viscous Coupling Unit)

stholt5233 said:

That evening leaving work I get a couple bangs and jerks, so I stop and take a look. Don't see anything, but I figured the VDU had failed and was the culprit. I left it at work and came in the next morning and removed the whole prop shaft to get ready to change the VDU(still trying to get the front shaft off the VDU). I hop in and start to back up and I still have the jerking and banging, seems like front left side, with the prop and VDU removed...very frustrating.

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If it's been driven with a bad VCU (stiff) and potentially odd tyres too, then it's very likely that the IRD (the Freelander's transfer box) has failed. It'll need replacement, as banging means it's now not economical to repair.

stholt5233 said:

Also...the black oil/grease that oozed out of the front prop shaft front connection joint to the IRD...it smells like RTV silicone...should I just repack this, or is there something I should change while the propshaft is out?

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The propshafts CV leaking is the least of your problems.

I have a feeling it is the IRD, but the noise and jerking seems to come more from the left front, rather than under my feet. The powertrain setup on these Freelanders is new to me, so I am not sure if I can lift one wheel and spin it to check the CV shaft, or if I have to lift both front tyres to check.

Right now it is in a parking lot, so I am limited as to what I can actually do. I have read about blocking the IRD off by removing the pinion and installing a plate...if the IRD is indeed what is causing the jerking and noise, then would doing this block at least get me 2WD until I can get it sorted?

If it banging and jerking, then the IRD is fubar. Trying to drive it will simply mash the other components like the front drive shafts and gearbox cross shaft. It needs to be recovered to a place where the work can be carried out, preferably with skates under the front wheels.

It has been left far to long with wind up occurring in the transmission. It has damaged something pretty severely - almost certainly the IRD.

If it is banging with the props removed, it is really (to quote a technical term) f**ked.

You can't always tell what is broken (or more accurately broken more than other bits) from where sounds come from - they tend to travel through the chassis and other bits and make it very difficult to know where its coming from.

You could try removing the rear pinion and replacing it with a blanking plate and put some oil in it and see if its the crown/pinion gears that are banging - this is the only fix that could enable the car to run 2WD. It could also be, as said above, the splines where the IRD mates up to the gearbox and passenger side drive shaft. It could also be the bearing keeping the IRD's diff and drivers side drive shaft in place.

I'm pretty sure the advice that a replacement IRD is needed is correct. Not the sort of thing you want to replace in a car park.

If you do try putting a plate on it, loosen the oil fill plug first - the last thing you want is to drain the oil, put the plate on and find you can't fill with oil because you've rounded the fill plug - which is often done as they are soft as cheese.

I am going to replace the IRD, boss is letting me pull it in the shop for the weekend.

I am still looking for helpful recommendations about the oil/grease coming from the propshaft front CV...can I just clean and grease it with good moly?

stholt5233 said:

I am still looking for helpful recommendations about the oil/grease coming from the propshaft front CV...can I just clean and grease it with good moly?

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If the joint is leaking, then you'll need a new boot. It takes normal CV joint grease.

stholt5233 said:

...The trans is in neutral, but I can not turn the output of the IRD by hand...not sure if I should be able to.

Thanks!

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Yer need to lift one front wheel for the rear pinion in the rear of the IRD to turn, if the rear prop is disconnected.

If all the 4x4 components like prop shatfs and vcu are fitted, then lift one front and one rear wheel on the same side. Turn one and the other lifted wheel will turn, via the prop shafts.