Fl1 knocking/ noise under feet when on full lock.

Hello I have a td4 fl1 with a banging/dragging noise under my feet it doesn't happen all the time and seems to happen mainly when on full lock or in reverse so very hard to replicate when I am under the vehicle and I dont have access to a ramp at the moment.

I have a good VCU and no play in any of the shafts going to or from the IRD.
No play in prop or rear drive shafts.

Cant see any obvious bushes that are worn enough to obviously cause a big noise like this
But I did notice the exhaust seems to have been hitting the body i have a part number on exhaust which seems to be 113479832030.

Does anyone have any idea of a common fault that causes this?

I dont really want to start chucking parts at it just yet as I have just bought a first house cheers.

Banging on lock, is often down to the IRD crown wheel missing teeth. Has the vehicle been used with odd makes of tyres? Or had new tyres fitted to the front?

Nodge68 said:

Banging on lock, is often down to the IRD crown wheel missing teeth. Has the vehicle been used with odd makes of tyres? Or had new tyres fitted to the front?

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No it hasn't, I did think it might have an ird issue but doesn't seem to happen all the time no play on the prop or drive shafts made me think it probably isnt faulty?

Thanks

If its the crown wheel it makes a seriously big bang, it couldn't be confused with a knocking sound - at least that's from my experience, even just pushing the car gave cringing bangs.

If it happens on lock and especially in reverse, it does sound transmission related though. There will always be wind-up on Freelander on lock - just a working VCU won't let it get to damaging levels.

Have you checked the mounts on the rear diff (especially the front one) - they do break down and have a limited life span - aftermarket ones can have an alarmingly short life span. Similarly the VCU support bearings.

Might be worth changing the oil in the IRD though. If the old oil comes out grey/metalicy in colour then that's a sure sign the IRD is knackered - and I'm pretty sure that can onyl be caused by poor tyre management (mixed makes/bad pressures) or a VCU that is overly tight. If it comes out looking like used oil, then the IRD is healthy.

Johnnod said:

No it hasn't, I did think it might have an ird issue but doesn't seem to happen all the time no play on the prop or drive shafts made me think it probably isnt faulty?

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Change the oil in the IRD, and see what it looks like. Dirty brown is ok, but if it looks like it's got silver particles in suspension, or it looks like dark silver paint, then the IRD is goosed. In my experience, mismatched tyres destroy the IRD, which is why correct tyre maintenance is most important.

How do you know the VCU is ok? Have you done the one wheel up test?

GrumpyGel said:

If its the crown wheel it makes a seriously big bang, it couldn't be confused with a knocking sound - at least that's from my experience,

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If the crown wheel is just starting to disintegrate, and a piece of one tooth has broken away, then a knock under load is possible.

I saw a similar thing a few years ago, which was caused by mismatched tyres.

Thanks fellas.

I have a brand new VCU and prop bearings from bell engineering fault was there before I fitted that but not as bad.
.
I drained the oil in the ird tonight and it was a really good colour with virtually no swarf on the magnetic drain bung, from what I could see through the filling bung the gear looked in good condition with no play on drive shafts or prop coming out of the ird.

Think I will drop the inspection cover off the diff this weekend and see if any metal is inside it

I would still do a 1 wheel up test - Bells are about the best in VCU reconditioning, but they are only human, so best to check it.

Have you checked the mounts on the diff?

Banging under feet for me was one of three things. the big bushes at the end of the wish bones or the anti roll bar bushes or the roll bar hitting the body work