Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Leaf spring replacement

Hi can any one tell me if a pair of four leaf rear springs can be used to replace a pair of five leaf springs. The car they will be fitted to is a 1970 4/4 two seat car fitted with a 1600 cc Kent engine. The car left the factory with 5 leaf springs which are looking sad and I have acquired a new set of 4 leaf springs hence the question. They will fit but what would the consequence of fitting them be?

I've just replaced the 7 leaf springs in my 1972 4/4 (4 seat) with 4 leafs springs. Check out my thread. Failry straightforward but a few things to be aware of.

Here we go: Changing Rear Springs

In the main a better ride.
You may want to consider the same mod to the dampers as Phil above has done, too.

Graham, Thanks but I am going the opposite route to TBM in that I am fitting a Rutherford suspension hoop and adjustable shocks and doing away with the original damper set up.

TBM, thanks for the link to your replacement article it is very informative .
When you say that it the moved the axle back a bit why is this and am I understanding you right that the axle moving back has caused the handbrake rods to catch on the fuel tank.
Did you have to replace the axle U bolts for different ones to suit the reduced dimension of the spring.

The axle locating pegs on the new 4 leaf springs are a few mm further back on 'new' springs. I thing it's because they're a generic 'one size fits all' across the model range.and the newer BTR axle sits a bit further back.

This meant the handbrake roads were catching on the tank, and the compensator was touching. It was really easy on the 4 seater to move the tank back, but another easy option is to trim the axle handbrake bracket by 10mm. As every Morgan is different it might be worth fitting and seeing how much you're affected.

I bought new U bolts (good practice). They;re almost at the end of their thread though - might be tempted to stick a washer in them (once I've trimmed the down - it was a very slow process)

On later cars, MMC de-centred the rear wheel w.r.t the wheel arch, I’m not sure when this occurred (introduction of long door cars?)
A consequence of this was that Mulfab (and maybe others) produced an aftermarket centring block that moved the axle back.
After a number of years, MMC hit upon the idea of relocating the mounting pin further backwards (date when?). Since then this is the spring format that MMC,and others produce to.
For any car with Girling back plates and a rod operated hand brake this current format of spring will have an interference between the the wiffle tree and the fuel tank. For those with Lockheed brakes with cable operation this should not be the case.
The work round is use a Mulfab centring block and use it mounted through 180 degrees to push the axle forward. It will all appear obvious when the new and old springs and their respective distances between the mounting pin and front eye are compared.
A side effect of the above work round is that the rear will be slightly lowered.

As a separate question, when MMC moved the spring mounting back: did they change the geometry of the rear roll hoop or just expected compliance in the shock absorber bushes to take up any gap at the top mounting pin?

I considered this, but the downside is a) £150, b) lower rear end and c) axle remains 'uncentralised'

The tank move option was free, easy (four holes drilled through wood) and I get a centralised axle as a bonus! Trimming the compensator mount has the same positive result..