Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing How to: Replacing leaf springs.

Springs should last years, I was talking to an owner of a 1934 Alvis yesterday and the springs are the originals.

Yes Mogs seem to suffer from sagging bottoms over time. Is this because the demand for leaf springs is so small they are not of the quality they once were, or because MMC bought cheap?

I do like the idea of wrapping the springs: the Alvis had nice tailored canvas covers. I know a MOG spring is somewhat protected but the grease will dry out, which isn't good.

But I'm not taking mine off just to wrap them!

The reason for the recent sagging (apparently) is that when MMC changed from six leaves to four, the spec wasn't good enough and a different supplier was sourced in '2012'. I say this because Mulfab were surprised that Bumble was sagging, and think that he may be one of the last with the weak springs. It was our Scotland tour that really brought this to my attention.

Anyway, a few stats:
Almost all the fasteners are 5/8"AF.
The seat belt nuts are 16mm, the bolts are 17mm.

Here are a few unscientific measurements:
New spring measurement of unloaded camber - 15cm
Old spring measurement of unloaded camber - 12.2cm

From lower plate to chassis - (bigger measurement = lower ride height).
Old springs - N/S 6.5cm, O/S 7.3cm.
New springs - N/S 2.6cm, O/S 3.0cm.
Gain in height ...3.9cm, ... 4.3cm.

Clearance to body where contact took place - old spring 2.8cm, new spring 4.8cm.

To underside of running board at rear (just in front of rear wheel):
Old springs: N/S 21.0cm, O/S 20.4cm
New springs: N/S 23.8cm, O/S 23.8cm
Gain .............2.8cm, ... 3.4cm

Next will be a road test. Pressures set to 24psi.

If I were a Boy Scout I would now be sewing on my Leaf Spring badge, next to my Kingpin badge, and Creative Use of Neoprene badge.

Don't forget your encyclopedia editor badge Dave.
What an excellent source of info you are.
I'm sure everyone will agree with my thanks for your work on this site.
Nick

Indeed excellent !
Many thanks,
Chris

Thanks both - always a pleasure!

We've been out for a test run today, and the rear is transformed. No more crashing over potholes, and a nice firm well damped ride. Even MrsW noticed the improvement.

Everything looks fabulous... photos, surroundings and car. Thank you for sharing

Living in Yorkshire does have a few perks!

Stand by for the "Grand Depart" in about ten days when more of Yorkshire will be on your TV's for a day or two. I might stay in bed until the crowds have gone away.

From what you say my 2009 Roadster may have "poor quality" 4 leaf rear springs. After 24000 miles I guess that I need to check for a "saggy bottom"

You measured your 2012 as follows:
To underside of running board at rear (just in front of rear wheel):
Old springs: N/S 21.0cm, O/S 20.4cm
New springs: N/S 23.8cm, O/S 23.8cm
Gain .............2.8cm, ... 3.4cm

I measured the same place:
Aldermog N/S 20.4cm. OS 19.6 cm

This suggests that all isn't well. Unless the roadster is different...What are the measurements on your Roadster?

I'd planned to fit a Panhard rod and AVO rear shocks, hope I don't need new springs as well?

Peter

Peter,
I just checked mine. It is an 2006 S1 with AVO shocks.
N/S 20.4cm OS 19.7cm. Not easy to do as the car is in the garage and my drive slopes so probably would not give the right result.
But this seems similar.

Would be interesting to know what the spec is.
The car has alloys.

It doesn't bottom out at the rear (Ooh vicar)
John

John, yours should have six leaves and 3/8" U bolts.
I'll measure up shortly and post the numbers.
Before the change I could fit two fingers between the top of the rear wheel, and tyre. Now it's 4 fingers. Roadster tyres are low profile compared to Bumble's 70 profile so that will make a difference.

Roadster: N/S 22.8cm. O/S 21.6cm.