Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) rear suspension conversions

95 mm - I am puzzled, Peter. Perhaps the spring hangers are not the same on our cars? As the car isn't over the service pit right now I haven't measured mines. Instead I measured the distance between the rear wing and the rim of the rear wheel. It is 165 mm (the tire is new, 165x15/80).

Not much help, I'm afraid

Frank

A word about MGB conversions........

The first thing ..... is that new MGB springs are now such poor quality, that they have a very limited life before sagging, and I imagine that this is in part due to inferior quality steel. In the good old days, leaf springs went on forever, except on my Midget which ate them due to my harsh treatment.

Coil over dampers need to be close to vertical to work effectively, and the shorter they are, the more important this is. There has been one case I know of with an IRS rear end on a B, where the damper shaft snapped due to stresses induced by the angle. The IRS kit uses a Sierra 4x4 diff mounted in a tubular steel subframe which uses the existing mounting points. It's a good if expensive (£X,000) upgrade, but I doubt there's the space on a Morgan, and you would have to alter the front suspension to derive any real benefit.

The coilover solution using the existing axle is available for the B, you need trailing arms from the front chassis mountings to the axle, and more importantly some form of lateral location. Often this is by Panhard Rod, which doesn't take up much room. My Gilbern Invader had this set up with an MGC axle and adjustable coil overs. Same on the front with a modified TR set up. But the ride was worse than my BGTV8 which I had at the same time. An alternative is an 'A' bracket to the diff, which on the Mog, as Cereal said would need the U tube strengthening. My Dolomite had a similar set up, but Dolomites used to eat rear shockers due to the conflicting geometry. A pig of a job to change as well.

So - It would be possible to fabricate a coil over fix with Panhard Rod, but for the road I really don't think you'd find much difference, and for me, the antique suspension is part of the package.

Well said, Dave!

...and a block of hardwood between spring and chassis instead of a panhard rod - like a Flat-Rad racer who's name I have forgotten had it - is the ultimate of innovation for a Morgan

Frank

Hope you don't mind me coming in on this discussion, but have a 87 4/4 fitted with factory hoop frame telescopic shocks, not sure what brand as was fitted by previous owner. The problem is bthr diff hit cross hoop on sudden bumps.

I think my rear springs are sagged, will check number of leafs etc.

Does any one know the correct ride height for 87 4/4 2 seater Lowline??

And how to remove rear springs.

Should they be reset or replaced??

David

You guys are all far more auto technical & experienced than I will ever be.

However, my original suggestion was to just replace the exiting rear dampers with what you call Spring Over Dampers to add support to the Sagging / Weakening Leaf Springs, not to replace them.
Would that not work without these pretty dramatic modifications?

We're concerned that the rear hoop which carries the dampers (assuming you have the hoop type mounting) will not be able to carry the load generated by the coil over dampers..

Also the overall geometary of the damper mounting which could result in premature damper failure due to the internal stresses of the unit....

So the answer is "yes" but probably would result in busting the rear suspension or certainly premature failure of several components... most notably the rear damper mounting hoop!?

Then again, I've not tried this but would anticipate these would be the problems looking how the rear hoop is installed and the impact the additional springs would have.

On the MogVette (+8+) coil-over dampers are used on the factory hoop, but with reinforcement brackets supporting the upper damper mountings. Unfortunately, I cannot find a photo of this setup.

Harald

Air adjustable shocks, damper mounted coils or air bags all have mounting problems if available in sizes to fit a Morgan
I'd like to see the MogVette set up though.

I measured my 4/4 today, it has 5 leaf springs, 70 mm clearance between diff and ply cover, approx 35mm between diff and hoop.
Springs appear slightly past flat.

Noticed one shock has given up since we had a run to Melbourne and back 2 weeks ago, 1900kms in 4 days.

I think it may be re spring time.

I have read so many different answers to my original problem, that now I am totally confused and very wary of doing anything about my rear suspension at all.
Has anyone every converted the Morgan to pure coils at the rear? that makes 3 bob's worth so far...
Surly the factory supplied hoop conversion and shockers is OK? why would they make it available to the public if it were not safe and reliable? I had considered purchasing one of these "kits" , but with all your reports of gloom and doom, I really dont know which way to turn?
Peter

Not quite doom and gloom.....

The Morgan hoop kit retains the oem leaf springs and the main spring device and only adds dampers which are generally used in soft mode. This is well tried and tested and is currently employed on all new trads.

It's the use of coil springs as a significant or esentially replacement primary spring device. That introduces different stresses the hoop was not originally intended for.

If you intend keeping the oem springs then the hoop is fine... There are several race v8's that have ford IRS back axel conversion although this is fitted at construction..... Chas Winderage at MogSport I think built these.