Freelander IRD

[woko]

Would anyone have a old IRD unit that the case is not damaged on?
I will rebuild it. I need it out of a K1.8 or diesel (L or TD4) I think my brothers has done his and it has lost all the oil so guessing the case has cracked. Have to pick it up tomorrow.

[woko]

Yep has hole in it. Pinion bearing has failed and pinion gear has warn a hole in it. Im willing to pay for any IRD that case is ok.

[woko]

I have got hold of one. Will let you know how the rebuild goes.
Still after a spare if anyone's got a old one for sale.

[woko]

All bearings have been ordered and should be here by Wednesday.
Removed cooler with out damaging but crown wheel had been rubbing on it so have to replace.
Crown wheel and pinion have been damaged and the current manufacturer has gone broke, so these parts are scarce at the moment until another manufacturer starts making them. I did find a supplier but it has doubled the price of crown wheel and pinion.
I'm going to convert to be a 2wd in the mean time. The only off bitumen this freelander sees is about 500m of a gravel road once a month if lucky.

[woko]

Have it all back together. just need to fit. I did have some troubles finding 2 of the input shaft seals as they have a 43mm id, but I did find them. The only seals shown on LR micro cat are the RH output and pinion seal, the 4 that seal input shaft are not sold through LR.
Very easy job to do. There are 2 bearings that can be difficult to remove. 1 is on the crown wheel and the other is on the diff assembly. required welding the bearing to remove.
Looking on LR micro cat looks like the only shims available are for the pinion so to shim crown wheel and diff you may have to make shims.

[Ace]

is it the Viscous Coupling that causes this to fail?

Will these touble some VC's have been done under warranty on these vehicles by now?

I know in 2000 models onwards they were rectified

[101RRS]

In the pre 2000 FL1s the difference between the front diff ratio and the rear diff ratio was too great causing the VCU to be loaded up. When it failed after about 120,000km it locked causing transmission windup which resulted in bearing failure in the rear PTO of the IRD which allowed the rear crown and pinion of the rear PTO to unmeash (IRD failure).

At the start the IRD could not be repaired and was replaced and the new item had a different diff ratio so the VCU was not loaded up and did not fail so early. Later, parts became available to repair the IRD so on these the old diff ratio might exist - also if a second hand unit was installed an early one could have been fitted.

I would expect that by now most would have the later IRD fitted but there is no guarantee.

Garry

[Ace]

In the pre 2000 FL1s the difference between the front diff ratio and the rear diff ratio was too great causing the VCU to be loaded up. When it failed after about 120,000km it locked causing transmission windup which resulted in bearing failure in the rear PTO of the IRD which allowed the rear crown and pinion of the rear PTO to unmeash (IRD failure).

At the start the IRD could not be repaired and was replaced and the new item had a different diff ratio so the VCU was not loaded up and did not fail so early. Later, parts became available to repair the IRD so on these the old diff ratio might exist - also if a second hand unit was installed an early one could have been fitted.

I would expect that by now most would have the later IRD fitted but there is no guarantee.

Garry

thanks Garry, makes sense to me now. Matt

[woko]

This failure was on a 2001 TD4 with 200K. The VC had not seized but was difficult to turn. The pinion bearings had collapsed.
After some research I have found out the viscous coupling should be replace between 120K and 150K. And this should be for all manufacturers as I have found it is also common on Jeeps, Hyundai's and Subaru's. Why this happens is the coupling is oil filled and the oil brakes down with age. If you could change the oil it would be fine, but it is a sealed unit, I'm going to add a drain and fill plug to the one that came off and change oil but I'm having difficulty finding oil. I can find a supplier in US but not AUS
You can tell the difference of which IRD you have as the casings are slightly different.
You used to be able to get different ratio crown wheel and pinions so the front and rear ratios difference are lower but the company making them have gone broke and they are difficult to get.

[Ace]

This failure was on a 2001 TD4 with 200K. The VC had not seized but was difficult to turn. The pinion bearings had collapsed.
After some research I have found out the viscous coupling should be replace between 120K and 150K. And this should be for all manufacturers as I have found it is also common on Jeeps, Hyundai's and Subaru's. Why this happens is the coupling is oil filled and the oil brakes down with age. If you could change the oil it would be fine, but it is a sealed unit, I'm going to add a drain and fill plug to the one that came off and change oil but I'm having difficulty finding oil. I can find a supplier in US but not AUS
You can tell the difference of which IRD you have as the casings are slightly different.
You used to be able to get different ratio crown wheel and pinions so the front and rear ratios difference are lower but the company making them have gone broke and they are difficult to get.

whats the replacement VC unit worth?

[101RRS]

whats the replacement VC unit worth?

Ashcroft Transmissions (http://www.ashcroft-transmissions.co.uk/index.php?act=viewCat&catId=18)

also a company from western Sydney advertises them on ebay about once a month for about $1100 buy it now.

Garry

[woko]

Unsure of price in Aus. but can get them from UK for 200 Pound exchange plus freight. If you are not going to use it off road you can remove the tail shaft and it will be a 2wd.

[Ace]

thanks for the info

[aikendrum105]

Hi Folks,

re the VCU fluid in case anyone's interested - I had a good read around the web for info on it - what it's called etc...( 12500 CS polydimethyl siloxane) and have managed to source some from a crowd in Adelaide. About $120 for 2kg of it.

The VCU in our 2000 Freeloader is stiff, but still serviceable (just hit the 120k mark) - I'm trying to get my hands on a dead one here in melb, so I can drain/flush the fluid and replace with the new stuff to see how it goes.

[101RRS]

What will be the solvent to dilute the old fluid when removing it and then to flush out the the VCU?

[aikendrum105]

That's the million dollar question - I suspect it might be a function of pushing new fluid at the top to both force the a little of the old out at the bottom and dilute what remains - I read on the uk forums ages ago about someone doing something similar - just adding new fluid at the top and running it for a week to mix it around then draining out what they could - rinse and repeat.

The data sheet on the stuff I found didn't list a particular solvent as far as I could see.

[101RRS]

The tolerances between the rotors and stators in the VCU are very close and as the viscosity of the old stuff is either solid or close to it I doubt just putting new stuff in will work - the old stuff will have to be washed out first or the new stuff will not get to where it counts.

Garry

[Demi]

I must be lucky - I have done 240K and the VC hasn't failed. The 200 quid unit from the UK sounds the go.

What signs does one see if this thank is on the way out?

Cheers, Demi

[101RRS]

I must be lucky - I have done 240K and the VC hasn't failed.

Not lucky at all - you have the model Freelander after when all the design faults with respect to the IRD were fixed. It was the IRD that caused the VCU to fail which in turn caused the IRD to fail. There is actually nothing wrong with the VCU, so as the new IRDs do not overwork the VCUs, the VCUs do not fail and cause the IRD to fail.

A circular scenario somewhat:)

[Demi]

OK Thanks. Ace referred to a 2001 Td4 with 200K so I assumed mines was the same

D

[aikendrum105]

The tolerances between the rotors and stators in the VCU are very close and as the viscosity of the old stuff is either solid or close to it I doubt just putting new stuff in will work - the old stuff will have to be washed out first or the new stuff will not get to where it counts.

Garry

Hi Garry - long time between posts on this - apologies. (New bub, Sold house, new house - no time to muck about with the VCU) The VCU on our freeloader has stiffened up a little more since I last checked it, starting to skip / chirp the inside rear wheel going around roundabouts - Worried about damaging the IRD, so have got moving and removed the propeller shafts / IRD as a unit. (amazing how nippy the car is in FWD...)

I emailed the supplier of the Siloxane and asked about a solvent - received the following reply:

A hydrocarbon like white spirits or mineral turps works well. Being thick fluid it will take a while to mix in, or goes better if you can agitate it.

Which is good news from toxic chemical solvent point of view. I think I'll drill and tap an input and output hole 180 deg. apart on the face of the VCU near the outer circumference, load up what turps I can then button it up and run it in the car around the local roundabout for a few laps - drain and repeat - see if that yields some results. I would expect to feel the stiffness of the VCU disappear as the old fluid is diluted and removed and the stator / rotors inside freewheel more easily in relation to eachother.

Not 100% on how much fluid should be added to the unit when refilling with new fluid - but I'll weigh it before I start and after flushed - that should let me know how much is needed to fill.

Cheers,

Scott.

[hugh]

With regards to removing the silicone based fluid from a vcu.
I drilled a hole 6mm top and bottom of the vcu. Next I obtained a can
of engine degreaser and plastic straw which comes with it.Put as much as
I could into the top hole,bit messy,left it over night.Next day I got
The air gun on the top hole and blew it all out the bottom.This was done
with the vcu in the vice.When this was completed I could turn the vcu
with ease.Hope this helps.

[101RRS]

With regards to removing the silicone based fluid from a vcu.
I drilled a hole 6mm top and bottom of the vcu. Next I obtained a can
of engine degreaser and plastic straw which comes with it.Put as much as
I could into the top hole,bit messy,left it over night.Next day I got
The air gun on the top hole and blew it all out the bottom.This was done
with the vcu in the vice.When this was completed I could turn the vcu
with ease.Hope this helps.

But does it lock when required - the general consensus by those in the know is that there is usually damage to the rotors and stators as well. The experts do not consider them the be cost effective to repair - they need to be cut open (dangerous as they can explode) clean all the fluid (solid) out repair rotors/stators and reassemble.

Garry

[101RRS]

The VCU on our freeloader has stiffened up a little more since I last checked it, starting to skip / chirp the inside rear wheel going around roundabouts - Worried about damaging the IRD, so have got moving and removed the propeller shafts / IRD as a unit. (amazing how nippy the car is in FWD...)

I emailed the supplier of the Siloxane and asked about a solvent - received the following reply:

A hydrocarbon like white spirits or mineral turps works well. Being thick fluid it will take a while to mix in, or goes better if you can agitate it.

Which is good news from toxic chemical solvent point of view. I think I'll drill and tap an input and output hole 180 deg. apart on the face of the VCU near the outer circumference, load up what turps I can then button it up and run it in the car around the local roundabout for a few laps - drain and repeat - see if that yields some results. I would expect to feel the stiffness of the VCU disappear as the old fluid is diluted and removed and the stator / rotors inside freewheel more easily in relation to eachother.

Not 100% on how much fluid should be added to the unit when refilling with new fluid - but I'll weigh it before I start and after flushed - that should let me know how much is needed to fill.

Cheers,

Scott.

If the rear wheel is skipping etc I would have thought that was more diff than VCU - if your VCU slips it is still OK.

I understood Siloxane to be a concrete sealer so I am not sure what that has to do with VCUs.

VCUs are not basically rebuildable - even the experts do not do it - ask Ashcrofts.

Garry

[101RRS]

VCUs are not basically rebuildable - even the experts do not do it - ask Ashcrofts.

Garry

Ian Ashcroft posted this on another thread related to the RRC B/W VCU - works the same way as the Freelander one.

"Hi we used to rebuild/repack the viscous units but stopped when new became more economic. The silicon fluid in the coupling, when overheated, changes state and becomes solid, very like a solid lump of rubber. BE VERY CAREFUL if you attempt to split a unit, when the silicon changed state it expands and it often splits the weld, if it doesnt split the weld and you put it in your lathe to turn the weld off it will most likely EXPLODE blowing the end off, be warned.
Anyway assuming you split the coupling chances are a couple of plates are scrapped and will need replacing so you will need a second sacrificial unit, obtaining the silicon, with the correct viscosity and the anti oxident added is a nightmare (in the UK).
Hope this doesnt sound too negative but do be careful, I found out the hard way, ouch.
Regards Ian Ashcroft"

[aikendrum105]

** Massive apologies to Woko for the almighty thread hijack here.... let me know if you'd like this all moved to a new thread **

Hi Garry and Hugh - thanks for the info, and definitely appreciate the warning - I'll definitely take a lot more care when drilling into the unit after reading that (and start with smaller pilot holes...)

I guess my thought process about it is this - the VCU hasn't seized yet - it's still slipping - but has become much stiffer in the last 12 months than it was previously. The VCU test still works - but it requires a *lot* of force and significantly more leverage to rotate than the examples on youtube etc. (even to move it very slowly) As I understand it - the higher the force required - the more wear you have on the IRD Pinion, until you break it or chew out the bearings supporting it...

Likewise - marking the front and back propeller shafts with paint - you can see their relationship to eachother is changing.

The the inside rear tyre skipping / chirping when going around roundabouts - after removing the propeller shafts / VCU completely - the symptom is gone.

So assuming that the VCU is *still* operating - albeit very stiffly - the stators / rotors are still undamaged - and drilling the 6mm holes on either side and flushing the unit out with turps / degreaser would result in an open VCU - which would a) spin freely and b) provide absolutely no 4WD benefit at all.

Pumping in the new siloxane until the VCU weighs the same as it did prior to flushing, should result in a VCU that works correctly again - however... Ashcrofts point about the anti-oxidant additives is really important. How long the VCU performs before the siloxane starts to break down again will be the mystery. I wonder if using C02 (love the home brew) to pump in the fluid and flushing any headspace with it as well before sealing the VCU up might help with that...

I would completely agree that it would be pretty unecomical to do these on a commercial basis with so many unknowns - on the flipside - it will be interesting to see how much longevity (if any at all) $100 of fluid and a few hours stuffing about with the VCU / propeller shafts can give an old (but not seized) VCU. If you got 12-24 months out of it before it thickened up again - I think it would be worth it.

I mean - compared to the cost for a new one anyway...

We don't take the hippo (who coined that? - it's awesome) off the reserve very often - but it's been very handy in a number of situations to have that 4wd engaged (wet freeway evasive action included ) and it niggles me to have the thing crippled in 2wd at the moment.

Anyway :) I do really appreciate the advice and thoughts - keep it coming.

** edit - here's the thread i found that started me down this path http://forums.lr4x4.com/index.php'showtopic=51912 I don't know if Polydimethyl Siloxane with a CS of 12500 (relative viscosity ?) is the same grade / composition as siloxane used for concrete stabiliser....

Cheers,

Scott.

[aikendrum105]

Found this today - gotta give it to the VW guys for a user serviceable VCU - I wonder if these could be easily adapted to the Hippos...

YouTube - ‪T3 syncro Visco Kupplung zerlegen und instandsetzen Teil 6 - Das Zusammensetzen (4)‬‏

[2_stroke]

All bearings have been ordered and should be here by Wednesday.
Removed cooler with out damaging but crown wheel had been rubbing on it so have to replace.
Crown wheel and pinion have been damaged and the current manufacturer has gone broke, so these parts are scarce at the moment until another manufacturer starts making them. I did find a supplier but it has doubled the price of crown wheel and pinion.
I'm going to convert to be a 2wd in the mean time. The only off bitumen this freelander sees is about 500m of a gravel road once a month if lucky.

How do you convert them to 2wd buddie? Just grabed a 1999 freelander for the wife suburb driving and dont want to worry about the issue with the vcu locking. Anyhelp would be great and i know sweet fa about 4wd's lol have owned sadans my whole life.

[101RRS]

How do you convert them to 2wd buddie? Just grabed a 1999 freelander for the wife suburb driving and dont want to worry about the issue with the vcu locking. Anyhelp would be great and i know sweet fa about 4wd's lol have owned sadans my whole life.

Easiest is to simply remove the two tail shafts and the VCU in the centre. Guess you could even leave the VCU in place if you wanted. Just remove the two tail shafts.

With the mod done there is just a little more backlash in the front drive but not an issue and you tend to spin the front wheels a bit more but the car does feel a bit more nimble.

Garry