
 Originally Posted by 
Jof
					 
				 
				Hi Harry,
 I wonder why your front tyres are more worn than rear though, normally the IRD causes rears to wear more quickly. Or are you running in FWD mode only?
			
		 
	 
 In a perfectly serviceable FL1 the front tyres will wear about twice as fast as the rears - hence the importance of tyre rotation in a FL1 - because it has a VCU it is important that all tyres have approximately the same rolling diameter.  If there is a big difference between the fronts and rears it may cause the VCU to start locking up.
The reason front tyres wear is that the FL1 is basically front wheel drive.  With a serviceable VCU and same tyre wear all around the VCU is basically unlocked and it is only the friction in the system and IRD gearing (earlier versions only) that sends about 10% of power and torque to the rear when driving on the tarmac.  Hence most power goes to the front which is also steering.  Like all front wheel drives the fronts wear quicker than the rears.  Off road, the VCU locks when it detects wheel spin at the front and sends 50% power to the rear.  This can also happen when the VCU fails and locks causing abnormal wear on all wheels and then failure of the IRD and maybe rear diff.
In my view the VCU should be checked every 5000km as a precautionary measure and if found the be failing the car taken off the road and the VCU replaced.
Garry
				
			 
			
		 
			
				
			
			
				REMLR 243
2007 Range Rover Sport TDV6
1977 FC 101 
1976 Jaguar XJ12C
1973 Haflinger AP700
1971 Jaguar V12 E-Type Series 3 Roadster
1957 Series 1 88"
1957 Series 1 88" Station Wagon
			
			
		 
	
Bookmarks