Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Plus 4 knocking noise

Decided to sort out the loose tank this afternoon. Couldn’t for the life of me see how the rear of the tank decking is supposed to be fixed to the chassis or if something was missing or not. I even wondered if it was intentionally loose maybe to prevent any chassis twist stressing the tank. Anyway I did fix it in the end but it turned out to be a bit of a bodge job.

Made up two little kinked steel fingers and bolted them to the decking brackets. They just touch on the rear cross member (one either side) to stop the decking and tank flipping up. Hopefully they will still allow for a bit of chassis twist to minimize any stress transfer.

Befor and after

Rog, the same at my 2009 +4. This certainly produce more or less noise at any Morgan. I followed your solution, just have replaced both hoops, left and right, by longer ones. I do not recognise any reason why the tank/decking can't/shouldn't be secured in the rear of the decking. The noise I was seeking for long time disappeared. Thanks for the hint!

Did this remain until the last produced classic Morgans? Anyone can have a look on his more recent Morgan?

Peter

Nice work Peter. I see you have added an extra fixing screw too, neat!

That’s two cars now with loose decking so I wonder if it is by design then. As mentioned the only reason that comes to my mind is by having only front decking fixings it might just prevent any body twist from flexing and stressing the welded tank. Mine is certainly so much better. I can now jump the local humpback bridges on the Somerset levels silently, without a single clunk or crash.

Ps - If anybody is wondering what we are talking about, take a look at this video 6 mins and 19 secs in to see the tank flip up.