Jump to content
Click here if you are having website access problems ×

Rear springs / dampers


Recommended Posts

My car has just had a look over by the local mechanic prior to the MOT. He's noticed that when the car is jacked up & the rear suspension allowed to hang down the springs are free to move on the shocks by about 2". He reckons the shocks are too long for the springs??? Having had a quick look I think I'll have enough travel by adjusting the platforms however this is bound to have an effect on my ride height / handling. Currently the platforms are about half way along their travel, am I right in thinking the car will end up jacked up at the back if I screw them up to take up the slack? I'm guessing I could tinker with them just to get through the MOT and then change them back but presumable they shouldn't have this problem in the first place. Any idea what's wrong?



This shows the free play with the suspension hanging down



Full view of springs, this time with A frame supported with a jack



Pic showing my rear ride height, nothing unusual??


The car is a 2001 Roadsport A with what I assume to be standard RSA suspension.




Link to comment
Share on other sites

The springs will compress X" under the weight of your car at the back, so if you simply wind the platforms up by the 2" to compensate you will simply move the resting point up by the same amount and the back will be around 2" higher.

If you got a 2" longer spring of the same rate (lb/in) then you will effectively be doing the same thing as the car will start compressing the springs as soon as the wheels touch the ground but will only compress them by the same amount as the rate is the same and the weight of the car is the same, so say you get amount of sag = 2" higher again....


Not sure what the answer is though, I suspect it isn't an issue - my car does the same, but not quite to the same extent, I probably have about 10mm free play and I've never felt anything. Don't forget that the damper will slow the spring from reaching it's maximum length, by which time you'll have landed back on the ground 😬


Phil Waters

Link to comment
Share on other sites

Phil is correct and this is indeed 'normal'.


Firstly buy the mechanic a ruler the gap is an inch at the most and certainly isn't 2".


There are hundreds of sevens that pass MOT's with rear shocks like yours but if it is going to be a problem the only way to cure it is to fit some helper springs. Theses are available from DT and all the usual sources for a bit less than £20 each although a coupling ring would also be useful. They are 50mm or 100mm long and have a nominal poundage so that they take up the 'slack' your MOT man doesn't like but as soon as they weight of the car is put on them they compress to next to nothing and let the real spring do it's stuff.


Personally I'd argue it out as a feature of a light car and go to a different MOT garage if the argument fails.



Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...