Page 1 of 1

thight VC at MOT?

Posted: 18 Feb 2011, 08:45
by wimwolf
Hi. Some silly questions but I don't see it for the moment...(i did earlier...)

•Does the propshaft turns when both rear wheels are on a brake-test-rolling-thing and the gearbox is in neutral?
Can one rear wheel be turning around without activating the propshaft?

•Does the propshaft turns when the front wheels are both turning and VC is thight? I'd say yes, so brake test must be individual?

I did the test once (and passed) but then the wheels were on the rolling-thing one by one, not together per axle.

aargh.

Re: thight VC at MOT?

Posted: 18 Feb 2011, 16:13
by Syncrobaz
My mot man doesn't use the rolling road for ANY permanent four wheel drive vehicles for fear of damaging the transmision, Instead he road tests them using the old fashioned brake tester.

hope this helps, baz

Re: thight VC at MOT?

Posted: 18 Feb 2011, 19:48
by toomanytoys
Now, you might be lucky in Belgium, you may have the same prake seters as in france where they spin the left and right wheels in opposite directions.. thus the VC never sees the rotation.. if they do not spin opposite, then the VC will load, drive will go the the other end and the vehicle should shoot off the rollers... NOT GOOD...

Make sure your tester is aware, regardless...

If you did spin the wheels in the same direction and it didnt drive off the rollers then the VC must be "open"

Spinning 1 wheel only (1 wheel on the roller 3 on hard surface), will result in the vehicle climbing off if the roller speed is high enough or performed for long enough to heat the vc....

Mine was MOT'd today my Mr Fullsunian.. Decelerometer .... and a nice PASS on the MOT too...

Re: thight VC at MOT?

Posted: 18 Feb 2011, 22:25
by silverbullet
I stuck a note on the dash that read:
"This vehicle has permanent 4wd with viscous drive to the front axle. Please brake test on 4 wheel rollers or road test. Parts are getting rare and expensive! Thanks"
Can't be too careful

Re: thight VC at MOT?

Posted: 18 Feb 2011, 22:38
by Fin
Had the same issue with my Golf Rallye when some plum of an Recovery man decided he could tow it on a tail lift type thingy.
Wound the diff up and pulled the bolts out of the VC.
Then the other plum at the garage when fitting the prop - split it and put it back together half a turn out - so of course at 140mph (on a closed road of course )
it fell apart - and I had to get new dougnutty things...
To add fuel to the fire - when I got my exhaust fitted the goons there then split the prop again, after I told them not to, Fudging idiots!! they even had 2 Delta's on the ramps
Oh and after shearing the bolts on the new rubber dougnuts I found the fudging garage had fitted the dougnuts the wrong way so there was no mechanical connection to prevent shear - only the bolts themselves.....AAAAArrrrrggghhhhhh!!
I now do my own mechanics
incompetent fools
Would never go back with a car that wasn't a plug and play type.....

Re: thight VC at MOT?

Posted: 19 Feb 2011, 14:13
by wimwolf
they spin the left and right wheels in opposite directions.. thus the VC never sees the rotation.. if they do not spin opposite, then the VC will load, drive will go the the other end and the vehicle should shoot off the rollers... NOT GOOD...


I see. Last time the van didn't shoot off the rollers and I'm pretty sure my VC is closed, so I suppose they do spin in opposite direction at my MOT station.
I only saw one wheel rolling, didn't check what the other one did. I told the guy to check one wheel at a time, he had to change some settings on the roller device.

So, same story for the front axle, no? Wheels must turn in opposite direction otherwise, JUMP.

Thanks, all clear now.

Had the same issue with my Golf Rallye

Expensive story.