UK MOT test advice / help
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Joined: May 2006
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From: NORWICH UNITED KINGDOM
UK MOT test advice / help
My local garage has done some work on my 1970 and has put it in for its anuall MOT test in the UK. The testing station has found movement in the rear axel and diff and is not sure if its normal and will not pass the car without evidence that this is normal for this car. They have asked me to find out and put forward a case where I may be able to prove this is normal. I am not quite sure myself ! This is what happens: if you jack up the rear wheels and suspend them off floor so that they hang down it is possible to move the wheel by holding the top and bottom (not left and right sides) by as much as 1 inch in and out. The garage say that the axel seems to be moving in and out of the differential. The car drives fine and if I can prove that this is normal for this car it will pass. I hope to have comments from you guys in order to help. If this is not normal of course I would expect to replace the part that may be worn, however the car does drive fine and I have no reason to expect to replace any parts. Quick replies would be most welcome as the mot runs out in 2 days.
Instructor
Joined: Jun 2005
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From: Bovingdon Hertfordshire
Mot
Yup,
Seems normalish - although a bit excessive!
Suggest you ask Scott at Corvette Kingdom (they are not too far away from you).
Jeremy.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>
Contact Us
Scott Groves
Workshop:
Unit 6, Tradebase
The Street, Catfield
Norfolk
England
NR29 5AA
Tel/fax: 01692 583307
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Seems normalish - although a bit excessive!
Suggest you ask Scott at Corvette Kingdom (they are not too far away from you).
Jeremy.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>
Contact Us
Scott Groves
Workshop:
Unit 6, Tradebase
The Street, Catfield
Norfolk
England
NR29 5AA
Tel/fax: 01692 583307
Email: info@corvetteuk.com
Melting Slicks
Joined: Nov 2003
Posts: 2,668
Likes: 119
From: St. Charles Mo
CI 5 & 8 Veteran
Originally Posted by 5day
My local garage has done some work on my 1970 and has put it in for its anuall MOT test in the UK. The testing station has found movement in the rear axel and diff and is not sure if its normal and will not pass the car without evidence that this is normal for this car. They have asked me to find out and put forward a case where I may be able to prove this is normal. I am not quite sure myself ! This is what happens: if you jack up the rear wheels and suspend them off floor so that they hang down it is possible to move the wheel by holding the top and bottom (not left and right sides) by as much as 1 inch in and out. The garage say that the axel seems to be moving in and out of the differential. The car drives fine and if I can prove that this is normal for this car it will pass. I hope to have comments from you guys in order to help. If this is not normal of course I would expect to replace the part that may be worn, however the car does drive fine and I have no reason to expect to replace any parts. Quick replies would be most welcome as the mot runs out in 2 days.
Bullshark
Last edited by Bullshark; Sep 20, 2006 at 01:02 PM.
Thread Starter
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Joined: May 2006
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From: NORWICH UNITED KINGDOM
Corvette Kingdom Result
I have spoke to scott at corvette kingdom and he has explained that as the rear axel is part of the suspension, it is quite normal for there to be movement in the wheel when unloaded other wise the diff would load up. He is going to speak to the guy that is doing the MOT and hopefully I will get my ticket for another year. The MOT inspector did say that he was unsure if this is meant to happen and was undecided whether to fail or pass the car. If all else fails I will take it to Corvette Kingdom for an MOT. I will keep you all posted in case some other member has the same problem with an over zellous MOT inspector.
Race Director
Joined: Dec 1999
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There should be next to no movement in the C clip, " the diff loads up" ?? What does that mean, the halfshaft is the upper control member for the rear suspension, much oif the rear load is on the halfshaft because of that. If the stub axle moves in/out you loose some camber and also toe control and it can make the rear behave real funky.
1" movement in and out is WAY too much, judging from the MOT guy's comments it's not the wheel bearing but the stub axle/c clip. You most likely have worn stubs, a worn center pin and worn clutches. Time for a rebuild
1" movement in and out is WAY too much, judging from the MOT guy's comments it's not the wheel bearing but the stub axle/c clip. You most likely have worn stubs, a worn center pin and worn clutches. Time for a rebuild
Thread Starter
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Joined: May 2006
Posts: 61
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From: NORWICH UNITED KINGDOM
I might be exagerating the 1 inch movement. What i mean is that when you grab the tyre at top and bottom points, and pull/push at those points, it is possible that the top of the tyre will move in/out 1 inch. I cannot help thinking myself that there is no problem because the car drives wonderfully.
Burning Brakes
Joined: Feb 2002
Posts: 752
Likes: 31
From: Melbourne Australia
Some play is normal
It is perfectly normal for the side yokes (axels) to move in and out when tested the way you describe. When new, this movement is almost imperceptible.
When the inner ends of the yokes begin to wear, movement will increase. There are specs for this, however movement of the yoke up to about 1/16" is probably OK and more than 1/8" is getting close to becoming a real problem because there are c-clips on the inner ends of the yoke that can fall off when the wear is excessive.
Any wheel bearing play or universal joint play can add to the tyre movement. So it is important to measure only the yoke movement. Wheel bearings can have up to 0.008" end float and are still in spec. (although not too good) and can contribute a lot to tyre movement when tested the way you describe.
Best regards,
Joe
When the inner ends of the yokes begin to wear, movement will increase. There are specs for this, however movement of the yoke up to about 1/16" is probably OK and more than 1/8" is getting close to becoming a real problem because there are c-clips on the inner ends of the yoke that can fall off when the wear is excessive.
Any wheel bearing play or universal joint play can add to the tyre movement. So it is important to measure only the yoke movement. Wheel bearings can have up to 0.008" end float and are still in spec. (although not too good) and can contribute a lot to tyre movement when tested the way you describe.
Best regards,
Joe
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