This is one of the updates that Simon Stirley put up onto the Freelanderclub Yahoo e-Group:

<div class='quotetop'>QUOTE</div><div class='quotemain'>The good news or the bad ?

The good news (for me at least) is that I've got the crown wheel and
pinion gears on order and they should be here today, so I'll be back
on the road at the weekend - all being well. The bad news is that at
least 3 of the bearings need replacing, and one shell is pressed into
the casing so I may well have to pay someone to put it all back
together for me [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]

The other news (you decide if it's good or bad in a minute ..) is
that I now know the cause of the problem. It may be bad because it's
destined to effect *ALL* IRD units. Without getting too complicated
there is one bearing that seems to take the majority of the load from
the prop-shaft, and this wears out first. As it wears it allows the
layshaft (inside the IRD) to slide and un-mesh the crown wheel and
pinion slightly, which as it gets more will allow it to 'jump' and
slowly nibble the teeth off. Eventually this escalates and ends up
with an IRD like mine.

A very simple test for this is to remove the filler plug from the IRD
and shine a light into the hole - you are now looking at the primary
gear on the layshaft. If you turn the right-hand driveshaft by hand
you will see it move the gear slightly, and if you're unlucky it will
move sideways also - mine moved over 10mm !! replacing that bearing
now will cost around ten pounds for the part, I'll be lucky to get
away with 300 - and the cheapest replacement unit was 650 [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]

I know the manual says the IRD is sealed for life, but if you want
the life to be more than 60-80k miles then I'd suggest changing the
oil at least every 24k miles - it won't take long and only cost about
2 litres of EP90 at most. I will be doing mine a lot more often than
that when it's back together ! not only will this keep the bearings
all nice and clean, but it will show you when wear is occuring - the
oil I drained out of the dead unit was practically silver in colour.[/b][/quote]

In the end, he got an engineering firm to put it all back together for him.

HTH

Mark.

__________________
'96 Camel 110 - Kalimantan CT11 - Video 1
'98 Camel Freelander - Sweedish selections
'98 TVR Cerbera 4.2 AJP -
'07 RRS TDV8 - The family car
'08 BMW 1200GS - The daily drive

Aim Low, Reach Your Goals, Avoid Disappointment.

This is great - at least my diff is still working and I can drive the car in 2wd with the prop shaft removed - at least my oil only had a little bit of crud in it and the magnetic pickup only had a little but of metal on it - no chunky bits

I think a new visous coupling from the UK is the way to go and a $1250 used 2000 model ISD is also the way to go. Might even have a go at rebuiding the old one like Simon Stirley did in my spare time - for a hobby.

Gazz

The propeller shaft is now removed and the car is running in 2wd. Seems the bits of the IRD that drive the front wheels are still OK. With the prop shaft removed there is no load on the rear drive part of the IRD and even though the bearings are shot they must be still good enough to work with no noise. Gears must still be OK. On removing the prop shaft I found that all the rubber mounts for the rear diff are completely chewed out and the diff was just sitting loose in its cradle - a bit of a worry but explains the rattle in the back when changing down gears!!

Have now driven about 80km in 2wd and all seems fine but I am not game to travel far from home - just to work and within the free NRMA tow range of home. The car drives really well - much less vibration than in 4wd and steering seems lighter. Can also spin the wheels up the road as traction control seems to cut in later with only the front wheels driving - doesn't seem logical but is the case.

New IRDs are around $2000 from both Aust and the UK. New genuine Viscous couplings are about $3400 in Aust but only $1000+shipping from the UK. Just waiting for a final quote from Ashcroft Transmissions in the UK. I will put in a new viscous coupling but will probably risk a used IRD from a 2000 model for $1250 - can get a 99 mod for $880 but I am not sure it will have the mods to fix the problem.

If the gears aren't broken why not just put new bearings in if that is the problem.

OK... Done a bit of research at this end.

IRD Part numbers.

The original IRD unit was TAG100030... This is the one to avoid. The later version was TAG000020 but this was replaced by TAG000230. Either of these is fine.

Chassis numbers.

The earlier IRD was for chassis numbers from WA000001. The updated IRD was introduced with the TD4 so that's chassis number 1A000001 onwards.

HTH

Mark.

__________________
'96 Camel 110 - Kalimantan CT11 - Video 1
'98 Camel Freelander - Sweedish selections
'98 TVR Cerbera 4.2 AJP -
'07 RRS TDV8 - The family car
'08 BMW 1200GS - The daily drive

Aim Low, Reach Your Goals, Avoid Disappointment.

Research to date shows no one is rebuilding the IRDs - Mark's earlier post on Sat also indicates trying to rebuild even if the parts are obtained is not easy - guess that is why no one seems to be reconditioning these. Even Ashcrofts in the UK only sells new units.

Is the IRD TAG number on the IRD housing next to the oil filler hole? Before buying a used unit I will need to check the number so I will not end up with the same problem. Mark you have been a great help, as have a whole lot of other guys.

Gazz

Hi,

I'm not sure where you'll find the TAG number. I'm hoping that it will be in the casting somewhere. :?

Mark

__________________
'96 Camel 110 - Kalimantan CT11 - Video 1
'98 Camel Freelander - Sweedish selections
'98 TVR Cerbera 4.2 AJP -
'07 RRS TDV8 - The family car
'08 BMW 1200GS - The daily drive

Aim Low, Reach Your Goals, Avoid Disappointment.

I recieved the replacement IRD and viscous coupling for the Freelander from Triumph & Rover Spares in Adelaide this week. The date on the IRD case is 12/00 so it probably came out of a 01MY Freelander which means I should be clear of the design defects of the 98/99 models.

The IRD looks almost new and is definitely low KM as there is no slack in any of the output shafts and all the cad plating is as new.

I will rebuild the tail shaft with new UJs before iI put it back in - the transmission windup that caused the problems in the first place also caused all the rear diff rubber mountings to be chewed out so I have replacements to go in.

The car has now covered about 800km on the U/S IRD in front wheel drive only - still makes the occasional noise when a damaged bearing catches but overall the car is very nice to drive in front wheel drive - but does defeat the purpose of an AWD vehicle - also the traction control cannot handle the torque of a front wheel drive Turbo diesel in the wet - can make things interesting in corners with too much power - traction control seems to take ages to kick in but it worked fine when the car was AWD.

Soon the freelander will be back to its old happy AWD self then I will be able to start on the transfer input gear of the Discovery to take out it driveline slack.

After the hippo is a goer I will pull apart the old IRD to find out why they are so difficult to rebuild and will take the oxy or angle grinder to the old viscous coupling to find out why overworking makes them fail.

I am good at pulling things apart - just getting them part together is the hard bit!!

Gazz