gort Posted October 8, 2012 Share Posted October 8, 2012 Next time your MOT is due, it might be be a good idea to to print a copy of this, and take it with you, to convince your local tester the Z can't be tested on the rollers, because there's a few out there that don't seem to know. http://www.dft.gov.uk/vosa/repository/11%20107.pdf Quote Link to comment Share on other sites More sharing options...
glrnet Posted October 8, 2012 Share Posted October 8, 2012 Nice one gort Mods, is it worthy of stickyness Quote Link to comment Share on other sites More sharing options...
gort Posted October 8, 2012 Author Share Posted October 8, 2012 as it's from VOSA themselves, and not some random guy on the Internet saying it, they might be finally convinced. Quote Link to comment Share on other sites More sharing options...
DoogyRev Posted October 8, 2012 Share Posted October 8, 2012 Nice one gort Mods, is it worthy of stickyness +1 My MOT place never had a problem with road testing, and knew about this. I guess it depends where you take your car and how competent the MOT man (or woman) is Quote Link to comment Share on other sites More sharing options...
KC350Z Posted October 8, 2012 Share Posted October 8, 2012 My tester said it comes on the screen when he puts the car details in but good way to make sure Quote Link to comment Share on other sites More sharing options...
spursmaddave Posted October 9, 2012 Share Posted October 9, 2012 As said any decent place wouldn't test it on the rollers anyway like most things once I find a good place I stick wity it rather than trying to save a couple if quid here or there Quote Link to comment Share on other sites More sharing options...
M13KYF Posted October 9, 2012 Share Posted October 9, 2012 Nice one gort Mods, is it worthy of stickyness done and moved into service as well Quote Link to comment Share on other sites More sharing options...
JetSet Posted October 9, 2012 Share Posted October 9, 2012 Of course VOSA don't want to damage your car, but running the test on one wheel sends a load of torque through the LSD which gives a false reading. Pete Quote Link to comment Share on other sites More sharing options...
kbeast35 Posted May 21, 2013 Share Posted May 21, 2013 Just had mine in for an mot and managed to stop the guy as he was about to stick it on the rollers, told him it had a LSD and he could damage it, to be fair he listened and took it up the road instead but afterwards when I spoke to him he said he was happy to test it either way and that the rollers shouldn't cause a problem, thought I may have upset him a bit but luckily it passed so all good, just a heads up that this is still happening! Quote Link to comment Share on other sites More sharing options...
jell36 Posted May 21, 2013 Share Posted May 21, 2013 When I mentioned it to my MOT tester he said he was glad I told him as otherwise it would brake his rollers. Quote Link to comment Share on other sites More sharing options...
GMballistic Posted October 10, 2013 Share Posted October 10, 2013 This forum is proving it's worth for me the more I read. Great information and come MOT time I'm going to make sure my local guy knows the score with these car's. Thanks gort Quote Link to comment Share on other sites More sharing options...
HassanZ Posted September 12, 2014 Share Posted September 12, 2014 (edited) The PDF don't work? Anybody got access to a working one? Edited September 12, 2014 by HassanZ Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted September 12, 2014 Share Posted September 12, 2014 (edited) I always use rollers. To my understanding if both wheels are spinning at the same speed then what's the issue? The brakes engage together on the rear axle not at different times of each other do they not? And its the brake application that stops the rollers! So if both rollers run at the same speed turning both rear wheels simultaneous, and both wheels brake together then please enlighten me as i fail miserably to get my head round it. I would have an issue if they did my 4x4 with the diff lock engaged, but that's completely different. This is my understanding and of course I could be quite wrong. We certainly did Haydens on the rollers last month! Edited September 12, 2014 by 4RE Leather Quote Link to comment Share on other sites More sharing options...
GMballistic Posted September 12, 2014 Share Posted September 12, 2014 I refer to your e-mails of 7th and 8th July 2011. We have dealt with this under the terms of the Freedom of Information Act 2000. You asked for the methods used at MOT test for testing the brake performance of your vehicle. I can confirm that all four tests were carried out using a Roller Brake Tester (RBT). You also asked whether the fact that the vehicle has a limited slip differential fitted it would be flagged up to the tester. This fact would not be drawn to the tester s attention by the system as this information is not recorded on our database. It may also not be obvious to a Nominated Tester carrying out the MOT test that a vehicle is fitted with a limited slip differential. However the MOT Testing Inspection Manual states at Section 3.7 Vehicles not to be tested on a roller brake tester Certain vehicles should not be tested on a roller brake tester, e.g. vehicles with · More than one driving axle permanently engaged · Limited-slip differential · Belt-driven transmission · Brakes for which the servo operates only when the vehicle is moving These vehicles should be tested using a properly calibrated and maintained decelerometer or a plate brake tester designated as acceptable for the statutory tests. A roller brake test is also not appropriate for vehicles with damaged, under-inflated or studded tyre Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted September 12, 2014 Share Posted September 12, 2014 I refer to your e-mails of 7th and 8th July 2011. We have dealt with this under theterms of the Freedom of Information Act 2000. You asked for the methods used at MOT test for testing the brake performance of your vehicle. I can confirm that all four tests were carried out using a Roller Brake Tester (RBT). You also asked whether the fact that the vehicle has a limited slip differential fitted it would be flagged up to the tester. This fact would not be drawn to the tester s attention by the system as this information is not recorded on our database. It may also not be obvious to a Nominated Tester carrying out the MOT test that a vehicle is fitted with a limited slip differential. However the MOT Testing Inspection Manual states at Section 3.7 Vehicles not to be tested on a roller brake tester Certain vehicles should not be tested on a roller brake tester, e.g. vehicles with · More than one driving axle permanently engaged · Limited-slip differential · Belt-driven transmission · Brakes for which the servo operates only when the vehicle is moving These vehicles should be tested using a properly calibrated and maintained decelerometer or a plate brake tester designated as acceptable for the statutory tests. A roller brake test is also not appropriate for vehicles with damaged, under-inflated or studded tyre It's all very well them saying don't do it but I want to know why? So please can someone explain in plain English without looking up Doctor Google Quote Link to comment Share on other sites More sharing options...
GMballistic Posted September 12, 2014 Share Posted September 12, 2014 Didn't even cross my mind that the Zed may have LSD until I read this thread back last year. Think it's more a safety thing than it will cause damage to the diff of a rwd car with LSD as I have heard they can jump out of the rollers?! Never seen it but heard of it so I for one won't be risking my Zed or any other rwd car with LSD. It's a definite no, no though to do it with a 4wd car with LSD as this can cause damage ~ more so because of the centre differential from what I understand, ...which isn't a lot. 1 Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted September 12, 2014 Share Posted September 12, 2014 I might stand up to attention after I put the quaife differential in, but I really want to know the reason why not. I am quite surprised that so many say you can't but no one has yet come up with a plausible answer. What makes it more of a mystery is 2 of the 3 MOT places I use the owner has a Zed lol Quote Link to comment Share on other sites More sharing options...
GMballistic Posted September 12, 2014 Share Posted September 12, 2014 I might stand up to attention after I put the quaife differential in, but I really want to know the reason why not. I am quite surprised that so many say you can't but no one has yet come up with a plausible answer. What makes it more of a mystery is 2 of the 3 MOT places I use the owner has a Zed lol Try typing it into google, ....this has been discussed at great length on Pistonheads, M3 cutters, MX5 owners etc etc Tbh it's probably been mentioned on pretty much every car forum ever since the internet began. Quote Link to comment Share on other sites More sharing options...
JetSet Posted September 12, 2014 Share Posted September 12, 2014 I always use rollers. To my understanding if both wheels are spinning at the same speed then what's the issue? The brakes engage together on the rear axle not at different times of each other do they not? And its the brake application that stops the rollers! So if both rollers run at the same speed turning both rear wheels simultaneous, and both wheels brake together then please enlighten me as i fail miserably to get my head round it. I would have an issue if they did my 4x4 with the diff lock engaged, but that's completely different. This is my understanding and of course I could be quite wrong. We certainly did Haydens on the rollers last month! Can't be 100% certain but the rollers are run one side at a time, it's only after they've tested each side they run the simultaneous test. You'd have to ask an MOT tester though. Pete 1 Quote Link to comment Share on other sites More sharing options...
GIXXERUK Posted September 12, 2014 Share Posted September 12, 2014 At my last mot the comp showed a warning that the rear should not be tested on the rollers Quote Link to comment Share on other sites More sharing options...
Floydbax Posted September 12, 2014 Share Posted September 12, 2014 As has been mentioned several times now on this thread. Since the MOT was changed several years ago to a pretty much computerised system (why it takes so long these days ) there is a warning to the operator about this that comes up on the screen. Although I always mention it just so they have it in mind and don't forget. Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted September 12, 2014 Share Posted September 12, 2014 At my last mot the comp showed a warning that the rear should not be tested on the rollers But did it say why? Quote Link to comment Share on other sites More sharing options...
4RE Leather Posted September 12, 2014 Share Posted September 12, 2014 I think it's best to agree to disagree. Until someone can come up with concrete evidence as to why. I am not going on line to look it up either. I have asked an MOT tester and they did not know the answer. Only a number of guesswork probabilities. I like these debates as they really stretch the imagination. Quote Link to comment Share on other sites More sharing options...
GIXXERUK Posted September 12, 2014 Share Posted September 12, 2014 At my last mot the comp showed a warning that the rear should not be tested on the rollers But did it say why? No, the tester asked if it had an LSD .. And thaft was the end of that ... 1 Quote Link to comment Share on other sites More sharing options...
Watshot Posted September 12, 2014 Share Posted September 12, 2014 It's because, as Jetset has already pointed out in post 19, the rollers are run one side at a time before being run simultaneously. This can potentially damage a LSD (and any 4wd set up). And don't rely on the computer flagging up your lsd to the tester. This info was in the 1st post: "You also asked whether the fact that the vehicle has a limited slip differential fitted it would be flagged up to the tester. This fact would not be drawn to the tester s attention by the system as this information is not recorded on our database" 1 Quote Link to comment Share on other sites More sharing options...
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