If you own a VW T5 (or a Toureg) with the 2.5 litre, 5 cylinder, AXE/AXD/BLJ diesel engine then here’s something you need to make sure either has been, or will be done on your van!

According to the service manual the following need to be replaced every 150,000 km (93,000 miles ish):

  • Alternator freewheel
  • Air conditioning freewheel
  • Alternator elastic coupling
  • Air conditioning elastic coupling

What on earth are these bits?  Basically, rather than the ancillaries being driven by a drive belt they are driven directly from the engine via gears and stuff.  Clever.  Yep, until something like your alternator or air conditioning pump seizes and you end up with a rather noisy, not to mention expensive, mess of an engine with lots of shredded gears and possibly broken camshafts.  Not good.

To safeguard against this, VW have put elastic couplings (sometimes called gates couplings, flexible couplings or gates flexible couplings!) between the engine drive and your alternator and a/c compressor which take the shock out of any sudden loads and, should the worst happen, fail before your engine gets trashed.  The couplings are just toothed rubber couplers that link 2 gears.  The air con compressor is driven from the back of the power steering pump.

The freewheeling clutch is like the freewheeling hub on your bicycle.  If you think of the alternator as your bike’s wheel and the engine as you pedalling; if you slow, or stop, the engine (gear change, turning the engine off etc.) then the alternator keeps spinning on (although it will slow quickly under load) just as if you stopped pedalling on your bike.  It’s a very simple component and is essentially a gear (that fits the couplings) with a one way, smooth ratchet type bearing (not the best description but if you get hold of one, you’ll see what I mean!).

Funnily enough, these parts aren’t overly cheap from VW but you can source OEM parts with a quick wander around Google and eBay.  Look for part numbers 070903327C or 070903327D for the couplings and 070903201C or 070903201E for the freewheeling clutch.  I got 4 pairs (2 vans x 2 couplings) for £140 delivered.

Fitting is DIYable if you’ve got the time although you will need a bearing puller or VW special tool to remove the old freewheeling clutches.  I won’t go into detail here on how to do it mainly because I got someone else to do it for me!  You need to take the front end off your vehicle (remove bumper and swing the radiator, intercooler and condenser away) so will take some time but once they are exposed it’s relatively straightforward.  I got mine done at my trusted local garage and got the air conditioning clutch replaced at the same time since I thought it wasn’t engaging properly.  Another £83.05 for the parts but thought it sensible on an 13 year old van with 140,000 miles on the clock.  Total cost of labour was £390 which also included getting the water pump changed too.

If you’re getting this done then I’d also recommend at looking at your power steering pump since it’s easily accessible whilst the couplings are being done.  They have a tendency for the oil seals to fail and you end up with engine oil in your power steering fluid which is an all round bad thing.  Check your power steering reservoir – it you dip it and the fluid is black then it’s probably on the way out.  You’ll most likely also have some power steering noise when manoeuvring.  If you get this done, remember to get some new green VW power steering fluid – not the standard ATF red stuff!

I gave our van a good test run by going down to Ile de Re in France – 1,500 miles there and back.  Very sensible, I know, but it didn’t miss a beat and the air con was lovely and cold again in the 35 degree heat on the way down (it was still cold in the 15 degree rain on the way back too).

NB: The same replacement is required on the BNZ and BPC engines but only every 180,000 km (112,000 miles ish) for some reason!