RRC Front Axle

It’s far too cold to be working outside at the moment, and I don’t have a pit or ramps to elevate the vehicle, so I had the front diff replacement done at Rogers of Bedford.  Just as well, too, as I didn’t expect the anti-roll bar links would be in the way.  It was possible to get the diff out without removing the bar with the vehicle high up on a four-post lift, but it wouldn’t have been possible laying on the floor on a vehicle supported on axle stands.  The clunking from the front axle was identified as preparations were made to swap the diff over: it was the near-side CV joint.  A bad CV will normally tick as it turns, but the clanking and banging of this one led me to suspect the diff.  Removing the half shafts to free the diff (instead of just removing the complete axle ends) was done so that the CVs could be checked thoroughly, even though it means more work in stripping the hubs and stub axles off the swivels, but it’s just as well it was done that way – the left CV joint had two enormous cracks in the bell that daylight can be seen through, one of which extends all the way across the cylindrical section of the bell and half way up the conical section to the output shaft.  I don’t know how much longer the part would have remained in one piece, but failure of CV joints causes a lot of other damage, wrecking the swivel and potentially damaging the diff, prop shaft and transfer box.  If it should fail at high speed and cause that wheel to seize, the control issues could be catastrophic.  I also found a mildly worn prop UJ which was binding very slightly, which was replaced while the prop was removed.  The good news is that the Borg Warner’s viscous coupling is still in good order – they cost well over £300 in pattern part boxes before any labour, other associated parts needed in the replacement and VAT are added.

The new CV joint had to be replaced complete with the inner shaft as Rogers didn’t have stock of bare CV joints.  This meant paying a bit more than strictly necessary as the original inner shaft is still in excellent condition, but as the complete new shaft cost less than a fifth of what Land Rover charge for a plain CV joint, it was hard to mind.  I have kept the old shaft as a spare.  CV joints are something that Britpart do curiously well – Ashcroft Transmissions conducted destructive tests on a range of CV joints from various suppliers, and the cheap Britpart CVs came second only to the very expensive custom HD Ashcroft CVs, beating the OEM parts by a considerable margin.  The CVs I was running were Britpart units that I installed about 80,000 miles ago and the off side CV is still as new.  I think the failed unit may have suffered from the heat of oil starvation – not a great deal of One-shot grease came out of the swivel housing as the stub axle was removed, which is a worry since that swivel was rebuilt with a new sphere, bearings and seals not long ago and I can’t see any signs of leaks.  I suspect the grease may have migrated to the axle casing.   All in, the job cost about £250, which is a very fair deal.  I have yet to see if that gentle thrum and vibration from the front end at 56-62mph which has plagued the vehicle throughout my ownership of it is still there (during which time the CV joins, wheel bearings, brake discs, tyres and prop shaft UJs have all been replaced), but it’s lovely and smooth around town.

The photos show the cracks of the old CV, with one picture showing that I wasn’t exaggerating about seeing daylight through them!