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Wales
by Joske Vermeule, September 1
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Forums39
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Jun 14th, 2026
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Joined: Nov 2010
Posts: 167
L - Learner Plates On
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L - Learner Plates On
Joined: Nov 2010
Posts: 167 |
Imbalance on the front wheels is more likely to interact(via a positive feedback loop)with the suspension spring's natural resonance than the same imbalance will with the back leaf springs. Bouncing on the front will also induce shimmy because of the rotational torque imparted by the compressing and expanding of the springs (which is why there are damper blades). In the back, only up and down motion is possible and resonant frequencies are presumably much lower, so a small out-of-balance condition may go unnoticed.
'65 +4 four seater
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Joined: Aug 2008
Posts: 2,515 Likes: 1
Talk Morgan Expert
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Talk Morgan Expert
Joined: Aug 2008
Posts: 2,515 Likes: 1 |
Imbalance on the front wheels is more likely to interact(via a positive feedback loop)with the suspension spring's natural resonance than the same imbalance will with the back leaf springs. Bouncing on the front will also induce shimmy because of the rotational torque imparted by the compressing and expanding of the springs (which is why there are damper blades). In the back, only up and down motion is possible and resonant frequencies are presumably much lower, so a small out-of-balance condition may go unnoticed. That's what I meant. 
1972 4/4 2 Seater
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Joined: Nov 2009
Posts: 6
New to Talk Morgan
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New to Talk Morgan
Joined: Nov 2009
Posts: 6 |
I have had this problem with my '63 +4 since I bought it a year or so ago. I checked all the usual culprits and replaced the damper blades with no luck. Yesterday I received a kit from Mulberry Fabrications in the UK. http://www.mulfab.co.uk/ which provides all the parts to install a steering damper. Installation took about an hour and is fairly straight forward, involving drilling one hole. During a 15 mile test drive down all the bumpy roads that I could find, which normally induce the dreaded shake, I experienced none of the usual symptoms. Fingers crossed that this permanently solves the problem.
1963 Plus 4
1990 XJS convertible
1979 Triumph Bonneville
1988 Harley Sportster 1200
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Joined: Jul 2007
Posts: 28,911 Likes: 354
Salty Sea Dog Member of the Inner Circle
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Salty Sea Dog Member of the Inner Circle
Joined: Jul 2007
Posts: 28,911 Likes: 354 |
Have you checked the chassis for cracks and also that there is no rust pushing the gusset (or tri-angulation) plates welded to the chassis by the bulkhead away from the chassis rails?
All you're doing at the moment is covering up a fault condition, which could get worse...
Cheers,
Graham (G4FUJ)
Sold L44FOR 4/4 Giallo Fly
'11 MINI Countryman Cooper D All4
'90 LR 90 SW
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Joined: Feb 2007
Posts: 521 Likes: 2
Talk Morgan Regular
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Talk Morgan Regular
Joined: Feb 2007
Posts: 521 Likes: 2 |
Gusset! one of my favourite words - on a par with grommet! Have you checked the chassis for cracks and also that there is no rust pushing the gusset (or tri-angulation) plates welded to the chassis by the bulkhead away from the chassis rails?
All you're doing at the moment is covering up a fault condition, which could get worse...
Cheers,
Simon
2002 4/4
1936 Austin 12 light 4 Ascot saloon
2023 AMG Mercedes C300e estate
2021 Audi A1 sport
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Joined: Jul 2007
Posts: 28,911 Likes: 354
Salty Sea Dog Member of the Inner Circle
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Salty Sea Dog Member of the Inner Circle
Joined: Jul 2007
Posts: 28,911 Likes: 354 |
 We'll be back on that stocking thread in a minute... 
Graham (G4FUJ)
Sold L44FOR 4/4 Giallo Fly
'11 MINI Countryman Cooper D All4
'90 LR 90 SW
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