A guide to MOT Part-2

Many enthusiasts combine a thorough service along with the MoT and it’s a good get-it-over-with practice. Of course, a specialist will know what points need closer attention

Depending on design, there’s various ways of testing for wear which some not used to classics won’t know

Believe it or not some cars are submitted for the test with brakes like this! No comment is required…

If selling your vehicle, a fresh MoT helps. If buying, it merely means that vehicle met criteria on day of test…

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In part two of Dan Bindon’s guide, we look at suspension and tyre checks to ensure getting that all-important pass certifi cate, the VT20!

In part one we looked at body and chassis structure, lights and signalling and brakes. Here we check out the rest of the vehicle’s running gear – many points which are often overlooked by owners.

Suspension

It’s often said MoT testers don’t appreciate the difference between modern car suspensions and the types fi tted to older vehicles. But having spoken to many testers, it is apparent that they do, and often are more lenient when presented with clean and tidy classics, than when they are looking at ‘bangers’ in the 5-20 year old age range. Beginning with the underside inspection, all testers must check every bush and suspension arm for security and play. Suspension arms that have been welded for repair are an automatic fail, as are those that are corroded excessively, and too thin. You can check your bushes by inserting a lever bar, pry bar or at a pinch, a long screwdriver and pushing and pulling them to expose play and deterioration. Any that have severe cracking inthe rubber, to the point where they move too much must be replaced. Also, bushes contaminated with oil must be changed, as the rubber will have softened and the bush won’t be capable of holding its component properly. For cars with ball-joints, there should be no lift or excessive play in a joint or its ball-pin, and the ball pin shank should be unworn and not corroded, and any securing devices – split pins and the like – should be present and properly installed; split pins need at least one leg of the pin bent at more than a 90 degree angle. If your car has grease nipples, then each one should be greased immediately before presenting the car for MoT, as the fresh grease can take up small amounts of wear, and additionally it shows that you, as a classic owner are taking good care of your motor, which has a bearing on how the testerfeels about you and your car, though naturally it shouldn’t have any bearing! Springs shouldn’t be broken or excessively sagged. Leaf springs can be re-tempered, so get on to a specialist if your car has leafs which are sagging and bending down at either end. Coil springs are harder to check for loss of temper, but mustn’t be broken or ‘coil bound’, where one coil is touching the next above or below. Cars excessively lowered, or without suffi cient suspension movement (ie the car only seems to have suspension within the tyre sidewall movement) can be failed, so if you have a historic rally car, ensure that adjustable dampers are set to their softest setting before presenting the car for test. Shock absorbers, or to give their proper name, dampers, mustn’t be excessively leaking,and should rebound no more than once when given the ‘bounce test’ on each corner. When checking your car’s suspension, allow the front to hang free if you have struts at the front, and support under the lower wishbone if fi tted with wishbone type. This allows the lower wishbone to be checked by using a long prybar under the wheel rim. Finally, with the car safely supported wheel free, check wheel bearing play by grasping each road wheel at 12 and 6 o’clock and checking for free movement, and the same at 3 and 9 o’clock. With spoked wheels, examine each spoke for tension, and check the security of the spinners to make sure the wheel is on tight. Of course, with a wire-wheel car, youdo that every week anyway – don’t you? As more test stations move to ATL status – Automated Test Lane – the increasing use of‘shaker plates’ will expose more classics to a uniform degree of suspension testing, so be aware that the test might seem to get more stringent between now and 2015 when VOSA expect all stations to be ATL compliant.

Tyres

Cars built before 1933 have to meet 1mm tread depth requirements, while cars built since need to have 1.6mm tread depth across 75 per cent of the tyre width with visible tread remaining on the rest. Of course, the tester is also going to be looking for tyre size, to ensure that each axle has a pair of tyres of the same size, and should also be checking for legality if a combination of cross-ply and radial tyres is fi tted. The only legal way to do this is to have the cross-plies on the front but it’s still bad practice. Check whether you have cross-plies by looking at the tyre size. Radials are in metric and imperial, eg 165-13 or 165/80-13, while cross plies and bias-belted (American cross plies) are in inches. A comparative size would be 5.00-13, 5 inches wide for a 13 inch rim. The tester will also be looking for condition, cracking, cuts, and whether the tyre is bulged, meaning its carcass has failed. Spare tyres – amazingly – are not part of the test, so only you need to ensure it is serviceable yourself if you think you might ever need to use it! For your own safety, tyres should be as ‘fresh’ as possible as they deteriorate with age as well as mileage. And new/old-stock tyres are defi nitely for show use only. Wheels should be secure, not excessively damaged and correct for the job.