Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Ride Height

Delving in the innards of my Roadster at the w/e - to attempt a more permanent cure to my squeaking rear springs - I was puzzled to note that the o/s rear shock was more extended than the n/s (finger-width gap between the shroud and the shock body - no gap on the n/s).

Careful measurement on level ground confirmed that the car's ride height (unladen) at the rear wheelarch is exactly 1/2" lower on the driver's side than the passenger's. The same measurement at the front shows 1/4" down.

I'm wondering ... is this something I have to expect? I'm no lightweight (15st+), and it's mostly just me in the car: but at this rate, how much sag will there be after a few years? (I've only owned the car for 8 months: the first owner only did 250 miles in its first 4 months).

Does anyone have any similar experience? What's the view: should I be demanding new springs under warranty - or is this something I just have to live with?

Mine has a very slight list in the other direction (and I weigh a good deal more than 15st... ).
Check your front springs for sag / breakage as well as the rear.

Cheers,

Hi Nick my Sept 2011, 2500 mile plus 4 is showing the same differences
I measured from both ground level and also at wheel nut level
Both near side front and back were the same at 26 5/8ths
Off side front 26 1/4 and off side rear 25 1/4 inches.
I hope that helps.

Part of this is caused by the direction of engine rotation, illustrated when you blip the throttle when stationary.
If the engine rotates anticlockwise from the drivers seat, the resultant force on the car will be clockwise, so it will bear down on the offside rear. So hard acceleration will put more load on the offside than the nearside. Then you can add the weight of the driver. Leaf springs do sag. In an ideal world they would be of a material which resisted flattening, but cost dictates something below that standard. There is no pure engineering fix for this except replacement, although you could lower the nearside with a spacer as a short term solution. I wonder if Morgan have considered a single leaf parabolic spring upgrade. This is available for MGB's but with mixed reviews on longevity. Additional springing could be applied by a coilover set up on the rear dampers. It would need anti tramp as well on both sides.It's the sort of thing which could be done 'at home', as is the spacer plates on the bottom of the cross tubes. Maybe when I retire and have more time......

Were the tyre pressures OK?
My n/s rear losses pressure much faster that the D/S.
I set them at 25 psi and over the winter the n/s was 18.5 and the D/S 22 when I cam to start using the car again

Tyre pressures - all bang on.

I'd probably be less concerned about this if it wasn't for the well-documented Roadster sump clearance issue - with particular bias to the offside. Although the "sag" is currently worse at the rear, if it were to continue, it could only exacerbate the risk of punching a hole in the sump sooner or later

Interesting analysis of the effect of engine rotational forces Dave - thanks for that - I've certainly seen the effect in several cars with big North-South power plants I've owned over the years, as a momentary lurch on engine acceleration - especially at rest - but I've never heard of it having a permanent effect!

Think I'll get Berrybrook to take a look - one way or t'other. As there's another year of warranty to go, it would be as well to at least register my concern, doncha think?

...with list being caused by an internal weight as opposed to heel which is an external force. At least it's not loll

Morgan production cost is probably dominated by labour cost.
Hence, it would make sense to look into better materials for the leaf springs. Modern composite springs would weigh much less and thus reduce the unsprung weight, and they would last longer sacving service costs for the owners.

Harald

Nick
Engine torque shouldn't have a permanent effect if the steel was the right spec.
MGBV8's with parabolic springs are very prone to this, and there has been a lot of discussion over the years. A BV8 will visibly squat over the rear offside wheel under hard acceleration. In fact a guy who drags a BV8 at Santa Pod gets the nearside front wheel off the ground due to the twist.
The other force at play is that the axle tries to twist back if there is no anti tramp bar and forces the leaf spring into an S shape. This also has the effect of reducing the camber and lowering the back end, which can become permanent.
Good luck with the dealer - I imagine they will say it's within parameters.

Except the list is to the passenger side...