TD4 IRD Problem? Please help

Hello, have used this site many a time to sort problems on my TD4 but this time I'm stumped.

I recently changed the Clutch Slave cylinder myself on our 2003 TD4 (manual obviously). It took me a week working on my back on the drive but I managed it, just. Had to laugh at how inept Haynes manuals are these days but that’s another story!

All went well and the car drove perfectly until about a week ago when I got a slight brake pad burning smell in the cabin. This went away but has now come back along with a grinding noise (according to the wife) so I've just investigated it expecting to find a binding brake calliper or something. After taking the offending (or what I thought was) wheel off the pads are in perfect condition and no sign of heat damage to the disc and the wheel turned ok'ish. That's when I noticed that I couldn't rotate the wheel. At first I thought it was in gear, but no, it was in neutral but it is as though it is in gear. Someone could correct me but a lifted front wheel should be able to turn independently?

Here's what I'm thinking. Has some part of the IRD - VCU gone west and could the resulting "bind up" feed back to my 110K clutch causing it to give? Which in turn would give the smell I’m getting?

I'm off out to check the VCU in a moment after reading around the web, to see if it is part of the problem.

One thing I remember from when I changed the clutch slave cylinder is that I purchased the wrong (only slightly) grade of oil for the IRD. But at a guess the car has only done 500 miles tops since that work was done. The oil I put in was GL5 spec but was 75W-80 and not 75W-90 as recommended? Could this have done something?

I'm out of work at the moment, like many, so I’m obviously trying to keep the bills down so any help/advice will be much appreciated. Thanks in advance

Edit. Have just done the VCU test by jacking up a back wheel and trying to turn it. There is now way i could get it to slip and i'm no 9st weekling - so I think that is fubar! oh the joys of Freelander ownership!

Remove the VCU and props, check the IRD oil for bits of metal.

Thanks howardo,

Was thinking along similar lines having just checked out the 2WD blanking plates on ebay. So you think if there is no shrapnel in the IRD oil I could get away with just running 2WD? I hope so because £300+ for a VCU and £900+ for an IRD is not really an option at the moment!

Anymore thoughts/advice on the origins of the burning smell? or why the front wheels won't freewheel in neutral?

TIA

You won't know until you drive it in 2wd. Good luck.

Sounds like VCU

Drop the prop! No blanking plate required, leave the pinion flange in place, it will rotate freely.

Thanks Northern Irelander,

Which prop should I disconnect?

The front one complete with CV joint or the rear one?

Thanks

The long one that runs most of the length of the underside. Has the VCU in it and two support bearings as well.

stewart09 said:

Thanks howardo,

Was thinking along similar lines having just checked out the 2WD blanking plates on ebay. So you think if there is no shrapnel in the IRD oil I could get away with just running 2WD? I hope so because £300+ for a VCU and £900+ for an IRD is not really an option at the moment!

Anymore thoughts/advice on the origins of the burning smell? or why the front wheels won't freewheel in neutral?

TIA

Click to expand...

Sorry to hear about your troubles. Wonder if the burning smell is the clutch slipping a little & overheating as it tries to link the engine to the knackered & tight transmission. Hopefully once your in Mondo mode it should be ok. I take it when you checked your brakes, you checked that the calliper sliders were free & easy to move with no damage to their rubber boots?

Hi chromiumuk,

I'm resigned to going "mondo" as it really isn't an option to spend that kind of money on a car thats probably only worth 1500K in tip top condition. So hopefully the IRD has survived enough to still drive the front wheels.

The slipping clutch theory is what i was thinking but you've explained it a lot better (for the benefit of anyone else with similar woes). It could also be why my wife thought the brake was overheating on the NS as this is where the heat from the overheating clutch would be most prominent.

I did check the brakes carefully, they're mint. Pads,discs and calipers are like nearly new.

I will remove the propshaft and VCU tomorrow and report back here. Fingers crossed it'll see me right for a while longer yet.

Pretty sure the IRD doesn't drive the front wheels & should just spin freely once disconnected. Only thing I've heard is that if it's damaged or the bearings are gone it can seize rather than freespin but the only way to know is to try it.

Just found an interesting read about the VCU at this place Symptoms - Bell Engineering they recon the tests to see if the VCU is fubar'ed are complete rubbish!

I was contemplating replacing the VCU and getting shut of the car but i don't know how to check if the IRD has suffered. With both the front wheels jacked up i rotated them and there is an initial slightly tight spot. Will running mondo tell me if the IRD has survived?

Thanks for the input chromiumuk, much appreciated. Just to correct you though (so people don't get the wrong idea) the IRD does indeed drive the front wheels. It contains the front differential as well as the output for the rear prop shaft.

So anyone got any tips on how to check IRD health apart from dropping the oil? I'll be carrying out the work tomorrow and will report back here.

TIA

stewart09 said:

So anyone got any tips on how to check IRD health apart from dropping the oil? I'll be carrying out the work tomorrow and will report back here.

Click to expand...

With the rear prop off, remove IRD filler plug. Rotate the 'pinion' the rear prop was attached to and look at the gear you can see thru the filler hole. If this move/tilts sideways along it's shaft then the bearings are....erm.....'done for'. Last one I saw like that lasted about another month or so.

To answer your question in your first post, if you only jack up one front wheel it will not turn independently/freely. It would have to make the VCU slip in the same way as checking with one rear wheel raised.

If the ird was knackered you would know by the awful noise they make.

I suggest that before condemning the VCU you try the test using a torque wrench on the driveshaft/hub nut as discussed in the this thread. http://www.landyzone.co.uk/lz/f9/vcu-torque-test-78219.html

Thanks for the replys, much appreciated!

I've dropped the oil and apart from a bit of sludge on the end of the drain plug magnet the oil was clean.

I've removed the propshaft completely from pinion to pinion - not as difficult as I thought! I decided try the "bench" test on the VCU out of curiosity and I can't believe it, I got it to turn like it should do - very stiff and slowly!

I feel like i'm going to have egg on my face soon as I'm about to re-investigate the brake callipers. Are they prone to rusting the pots on a flander? and sticking on release sometimes?

Thanks for the reply on the freewheeling issue chaser - it just seemed alien to me when i jacked the wheel up and couldn't turn it... you'd think I'd know better having had 4x4's for a few years now

I took the car for a drive in "mondo" mode and it does make it a bit more lively and I expect a tad more ecconomical too! I'll leave it like this for a while I think. I had no noticeable noises from the IRD but just when i was coming to a stop under braking i heard a slight clicking noise??? I'm going to strip the calipers tomorrow and investigate - it could just be a loose shim or something.

The 2nd reason I could end up getting egg on my face is the clutch could be shot. I've never had to do a clutch in any cars i've owned so begrudged doing it in the flander when I had the box off to do the Slave cylinder. Could an ailing clutch appear to be OK but start to go gradually with a slightly tight transmission train? Or is it a case when you start looking for problems you make them?

I'll let ya know what I find - Thanks for all the help so far

Edit, sorry missed your reply Andy - I will try the IRD test you suggested tomorrow.

The front brakes can give problems if crud builds up at the edge of the pads metal backing plate as the pad retainers hold the pads so well in the calliper body they can begin to seize.

Just make sure the pads are free to move in the calliper body after cleaning and reassembly, ensure the guide pins are free and work the pistons a couple of times. (there will be some corrosion at that mileage). Open the bleed nipple when pushing the pistons in to prevent old/dirty fluid entering the ABS modulator valves and fecking it. A fluid change while your at it would be worthwhile if you don't know it's history.

If you don't get any clutch slip pulling hard up a hill then clutch is OK for now. I understand the need to keep costs down but while you had the box out a new clutch should really have gone in. (hindsight hey!)

Ok, Investigations completed

Turns out I had a small tear in the Calliper boot and the ingress of moisture has caused the lip that the boot sits in to rust. This has then jammed (as rust swells) the piston which in due course has not allowed it to return.

I was so convinced it was a terminal fault (is that a side affect of Flander ownership?) that i conviced myself it was the VCU-IRD oops!

So disaster averted for now (touch wood) and a new set of pads - seal kits on their way.

Thanks for all the help in my hour of need

stewart09 said:

Just found an interesting read about the VCU at this place Symptoms - Bell Engineering they recon the tests to see if the VCU is fubar'ed are complete rubbish!

I was contemplating replacing the VCU and getting shut of the car but i don't know how to check if the IRD has suffered. With both the front wheels jacked up i rotated them and there is an initial slightly tight spot. Will running mondo tell me if the IRD has survived?

Thanks for the input chromiumuk, much appreciated. Just to correct you though (so people don't get the wrong idea) the IRD does indeed drive the front wheels. It contains the front differential as well as the output for the rear prop shaft.

So anyone got any tips on how to check IRD health apart from dropping the oil? I'll be carrying out the work tomorrow and will report back here.

TIA

Click to expand...

Apologies for the bum steer re the ird, useful to know that.