six years of ownership and MOT's, and this has only just come to my attention!

[seddomyster]

how can rollers ruin diff? cant u put it in neutral an rollers will power wheels until brakes applied or are they tested differently

[bugeye_bob]

centre diff doesnt like the front wheels rotating and the rears not or vice versa

[seddomyster]

even if the car was in neutral?

[bugeye_bob]

if you jack your car (in neutral)up and rotate a wheel you will see what happens

[seddomyster]

ive never tried it to be honest mate. replaced brake calipers etc but never actually rotated a wheel. what actually happens. wont it budge after 1 rotation?

[QUINNtheDAWG]

car up for mot a tthe end of the week
but last year when i took it the guy moved me into the right lane and the screen showed up test on 4wd rollers in red flashing
here in NI they take this stuff very serious no independants

[stiimpreza1984]

Bumped into a subaru mech today with nearly 20yrs experience was asking all about the 2wheel rollers and what damage it can do, I knew his brother was working in one of the Nct(mot) test centres in the city here, he said for the amount of time the car is on the rollers and the rollers dont spin very fast and that normally the testers go into neutral anyway that the car not in gear so it shouldnt damage the diff for the small amount of time it on the rollers, it might be a different story if the tester left the car in first gear as the spinning of the rollers may go through the gears rather than diff but cause the testers only leave the car in neutral and the rollers not spinning fast it should not have winding the diff up but said that he said they should not put it up on 2 wheel rollers they should use the box thing and take car out to test the brakes as his brother working in the nct centre knows that AWD cars dont go on 2 wheel rollers

[brumbrum]

my mechanic/MOT tester said pretty much the same thing. I was in the car doing the brake test myself and the car was in neutral at the time., and the test was over in a few seconds.

But it's still not the correct thing to do. my mechanic said he always uses this test with all 4 wheel drive cars be it audi's, land rovers etc and has always put his own 4 wheel drive cars on it for testing.