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MG Midget and Sprite Technical - Frogeye Spring mounts

Another thing to check!
Whilst prepping the underside of my Frog for painting I have discovered a mystery. Well, its a mystery to me.

The rear springs fasten to the body inside two caves in the rear cross member, supported by two substantial spring pans below. But on mine there seems to be a secret tunnel at the back roof of each cave (i.e. towards the front of the car), connecting, I think, into the void of the rear box section bulkhead.

Its difficult to tell as I can only just get my hand in there and would rather not get my fingers trapped. It would be somewhat embarrassing having to ring the fire brigade and explain that I have my hand trapped inside the rear end of a frog. They might get the wrong idea.

With the spring not fitted, I would expect this cave to be fully sealed off to prevent road dirt getting where the sun doesn't shine. Have I missed a piece out when I assembled this bit? But I do seem to recall something about the original cars having some sort of flexible (rubber?) filler that is inserted after the spring is fitted. Maybe with that in position a tunnel leading through into the box section wouldn't matter.
GuyW

My Frogeye is the same. There is nothing to stop water and crap getting into the rear floor strenghthener. When I did the rear springs on mine I tried to fashion an ally plate to stop this but it was beyond my skills. I did it as best I could and stuffed it with half a tin of grease.

Rob
MG Moneypit

Thanks Rob.
I have been browsing my photo records from when I repaired this bit. I see I used a rear heel board that does close of the spring cave from going forwards into the rear floor strengthener.(its actually a torsion bar device on the 1/4 eliptic sprung cars). But that still left a void going upwards through the roof of the cave.
Pity, as I should have spotted that and it would have been easy to weld in an extra piece at that time.

Photo shows the rear bulkhead front panel. I think I used the later style one which has the blister to close off the from where the L shaped strengthener is then added. - you can just see it waiting amongst jumble at the right of the photo.



GuyW

And this is that same area before I started!

GuyW

Just out of curiosity Guy, I was expecting to see the longitudinal stiffeners on the floor panels, do they get added afterwards? (i.e. later than the pic).
davidsmith

Yes David, in my sequence of working. In that photo, the bulkhead panel isn't yet welded in either. Though I have fitted the inner sill and floor which is why the adjustable door gap brace visible in the "before" shot has been removed.
(there is another brace at the top of the door opening - the little threaded adjusters do make it easy to get the A and B post spacing right!)

Once the bulkhead front was positioned I then temporarily bolted on the hefty L brace which confirms and holds the floor/ bulkhead angle whilst welding the bulkhead. I then removed the L piece again, welded the floor stiffener in and then refitted the L piece. (photo). This all seems like a long time ago now!

The reason I called the floor stiffener a torsion bar (probably the wrong description) is that it acts as a long lever, attached to the floor and cross member at the front against which the spring pan and the spring can act. The later 1/2 eliptic spring cars don't need this sort of floor stiffener as the front spring mount doesn't impart much leverage into the shell at that point. I find it interesting that the bodywork around that area doesn't look a great deal different but the physics actually performs in a totally different way.

GuyW

In my service parts list for Midgets, there is a "seal assembly, spring housing" that seals off that area. It starts with 14527. That would be July 1962. Part number AHA 6418. It is held in place by the large U bolt. You can add them if you can source them. I only have one example in all the years I have collected Midgets and have never found anyone that has them. If you find a vendor please share the info.
J Bubela

Item 13 here - http://www.moss-europe.co.uk/rear-suspension-1-4-elliptic-sprite-i-ii-midget-i.html
Nigel Atkins

I made my own out of sheet metal and made them a close fit around the spring and put some sealer on. Might get around to removing some of those bits soon as I have cleared the stuff that was on top of the car for better access so I can then tell how they worked over the years.
David Billington

This is what it says in Nigel's M*ss link...


From (c) H-AN6 22907, from (c) G-AN1 14527


So it looks like they weren't fitted to Frogs.
Dave O'Neill 2

Sorry I failed to notice that (I went on to wheels).
Nigel Atkins

Hi. When I built my frog I used the closed panel to the front of the crossmember for just that reason. I was unable to source the sealing panels shown in the parts catalogues. I cut up a rubber inner tube, and wrapped the spring tightly in it. Sprayed in a full tin of white spe as y grease to each snoring mount, and the Dutch another bit of rubber to the panel around the spring mount and wrapped the "skirt" section around the spring. Seems to work well on very muddy rallies etc. I spray more grease in when wiring at the springs or once a year. Sorry I would send a picture but the technology baffles me.
Slowly

Guy, my shell is the same if I've understood your description. I'd assumed that the rubber seal could be used (Nigel's reference) but it's listed as NCA (not currently available). Maybe the Frogs never had them as they all rot away around there. David and Slowly's sealing methods sound ok.
Bill
W Bretherton

I like the idea of making a seal, though I would use a flap made from something akin to a piece of conveyor belting. Interestingly, it also looks like the bottom 1/3rd of a 2pint plastic milk container from ASDA fits rather neatly into the spring cavity as a liner. Maybe I do something with that!
GuyW

This thread was discussed between 28/02/2017 and 01/03/2017

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