Springs or dampers??

Ive noticed over the last month of so that my 1992 90 (150,000 miles)
HT is starting to roll more when I go round a right hand bend or
round-about. Going around left hand corners is still controlled and
has much less roll.

It feels as though the left rear is "weaker" than the front left so
consequently the right front seems a little high.

I have checked the damper and there is no apparent leak and the spring
is not dislocated.

I suspect this is a spring issue rather than a damper one?

Is it normal for one corner only to fail?

If it helps, my right rear bush that holds damper to chassis is ready
to be replaced as there is possiblyt 1/4 inch play in the bush...

Can I replace 1 corner only or should I replace the 2 rear only or is
all 4 necessery?

I know I have yellow Monroe dampers (replaced by revious owner) but
have no idea if the springs are original.

Any suggestions?

Thanks
Jon

Jon wrote:

> Ive noticed over the last month of so that my 1992 90 (150,000 miles)
> HT is starting to roll more when I go round a right hand bend or
> round-about. Going around left hand corners is still controlled and
> has much less roll.
>
> It feels as though the left rear is "weaker" than the front left so
> consequently the right front seems a little high.
>
> I have checked the damper and there is no apparent leak and the spring
> is not dislocated.
>
> I suspect this is a spring issue rather than a damper one?
>
> Is it normal for one corner only to fail?
>
> If it helps, my right rear bush that holds damper to chassis is ready
> to be replaced as there is possiblyt 1/4 inch play in the bush...
>
> Can I replace 1 corner only or should I replace the 2 rear only or is
> all 4 necessery?
>
> I know I have yellow Monroe dampers (replaced by revious owner) but
> have no idea if the springs are original.
>
> Any suggestions?
>
> Thanks
> Jon

Yes, dampers do not control roll, so springs sound more likely. But also
check the state of the suspension bushes, and possible damage or rust to
the spring seats and chassis, as free play could show up as initial roll.
Also, although the dampers are not intended to control roll, if one rear
damper is partly seized, it could give the effect you are seeing,
particularly if there is a lot of play on its bushes.
Without sway bars, the roll is controlled only by springs and the bushes on
the front radius arms, so these are the prime suspects, but as above, a
sticking damper could cause unequal roll effects. Unless broken, springs
usually sag equally. However, note that left and right springs are not the
same, either front or back, and having left and right interchanged will
cause a lean.
JD

In news:[email protected],
JD <[email protected]> blithered:
> Jon wrote:
>
>> Ive noticed over the last month of so that my 1992 90 (150,000 miles)
>> HT is starting to roll more when I go round a right hand bend or
>> round-about. Going around left hand corners is still controlled and
>> has much less roll.
>>
>> It feels as though the left rear is "weaker" than the front left so
>> consequently the right front seems a little high.
>>
>> I have checked the damper and there is no apparent leak and the
>> spring is not dislocated.
>>
>> I suspect this is a spring issue rather than a damper one?
>>
>> Is it normal for one corner only to fail?
>>
>> If it helps, my right rear bush that holds damper to chassis is ready
>> to be replaced as there is possiblyt 1/4 inch play in the bush...
>>
>> Can I replace 1 corner only or should I replace the 2 rear only or is
>> all 4 necessery?
>>
>> I know I have yellow Monroe dampers (replaced by revious owner) but
>> have no idea if the springs are original.
>>
>> Any suggestions?
>>
>> Thanks
>> Jon
>
> Yes, dampers do not control roll, so springs sound more likely. But
> also check the state of the suspension bushes, and possible damage or
> rust to the spring seats and chassis, as free play could show up as
> initial roll. Also, although the dampers are not intended to control
> roll, if one rear damper is partly seized, it could give the effect
> you are seeing, particularly if there is a lot of play on its bushes.
> Without sway bars, the roll is controlled only by springs and the
> bushes on the front radius arms, so these are the prime suspects, but
> as above, a sticking damper could cause unequal roll effects. Unless
> broken, springs usually sag equally. However, note that left and
> right springs are not the same, either front or back, and having left
> and right interchanged will cause a lean.
> JD

Tyre pressures?

--
"He who says it cannot be done should not interrupt her doing it."

If at first you don't succeed,
maybe skydiving's not for you!

>>>
>>> Thanks
>>> Jon
>>
>> Yes, dampers do not control roll, so springs sound more likely. But
>> also check the state of the suspension bushes, and possible damage or
>> rust to the spring seats and chassis, as free play could show up as
>> initial roll. Also, although the dampers are not intended to control
>> roll, if one rear damper is partly seized, it could give the effect
>> you are seeing, particularly if there is a lot of play on its bushes.
>> Without sway bars, the roll is controlled only by springs and the
>> bushes on the front radius arms, so these are the prime suspects, but
>> as above, a sticking damper could cause unequal roll effects. Unless
>> broken, springs usually sag equally. However, note that left and
>> right springs are not the same, either front or back, and having left
>> and right interchanged will cause a lean.
>> JD
>
>Tyre pressures?

All 4 of my tyres deflate slowly (loose maybe 5psi over a week) so I
check and inflate every 2 or 3 days. Therefore I know my pressures
are always around 32 - 35 at rear and 30 - 32 front.

Jon

>>
>> Yes, dampers do not control roll, so springs sound more likely. But
>> also check the state of the suspension bushes, and possible damage or
>> rust to the spring seats and chassis, as free play could show up as
>> initial roll

Will check the state of the mounts and bushes.

>> Also, although the dampers are not intended to control
>> roll, if one rear damper is partly seized, it could give the effect
>> you are seeing, particularly if there is a lot of play on its bushes.
>> Without sway bars, the roll is controlled only by springs and the
>> bushes on the front radius arms, so these are the prime suspects, but
>> as above, a sticking damper could cause unequal roll effects.

Front radius arms control roll? I didnt know this, will also need to
check the front end!

>> Unless
>> broken, springs usually sag equally.

I'm fairly sure I dont have a broken one, it would have shown up
whilst playing in a quarry yesterday.

>> However, note that left and
>> right springs are not the same, either front or back, and having left
>> and right interchanged will cause a lean.
>> JD
>


Looks like I need need to check all bushes and chassis mounts first.


Whats the best way to check bushes? Jack up the vehicle via the
jacking ponts and then use a trolly jack to lift the axle, then use a
pry bar? I have orange poly-buses if that makes a difference?

Thanks
Jon

Jon wrote:

>
>>>
>>> Yes, dampers do not control roll, so springs sound more likely. But
>>> also check the state of the suspension bushes, and possible damage or
>>> rust to the spring seats and chassis, as free play could show up as
>>> initial roll
>
> Will check the state of the mounts and bushes.
>
>>> Also, although the dampers are not intended to control
>>> roll, if one rear damper is partly seized, it could give the effect
>>> you are seeing, particularly if there is a lot of play on its bushes.
>>> Without sway bars, the roll is controlled only by springs and the
>>> bushes on the front radius arms, so these are the prime suspects, but
>>> as above, a sticking damper could cause unequal roll effects.
>
> Front radius arms control roll? I didnt know this, will also need to
> check the front end!

If you think about it, when the vehicle rolls, the front radius arms have to
be at a different angle to the axle - the only way they can do this is by
deforming the bushes. A bush that is no longer concentric would give a
slight lean, for example.


>
>>> Unless
>>> broken, springs usually sag equally.
>
> I'm fairly sure I dont have a broken one, it would have shown up
> whilst playing in a quarry yesterday.
>
>>> However, note that left and
>>> right springs are not the same, either front or back, and having left
>>> and right interchanged will cause a lean.
>>> JD
>>
>
>
> Looks like I need need to check all bushes and chassis mounts first.
>
>
> Whats the best way to check bushes? Jack up the vehicle via the
> jacking ponts and then use a trolly jack to lift the axle, then use a
> pry bar?


Yes


> I have orange poly-buses if that makes a difference?

No

>
> Thanks
> Jon

Sorry for the late reply, been away.
JD