Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 More worries - cracked gas tank.

Just found this stress cracked, left side, fuel tank mounting bracket on a 9000 mile 2014 M3W.


I suspect that there are many people driving around with similar cracked brackets as it's not an area that can be easily inspected without removal of the alloy bulkhead behind the seats.

There is plainly a design issue here. Does anyone know if Morgan have modified/improved the design on new fuel tanks?

Just found this stress cracked, left side, fuel tank mounting bracket on a 9000 mile 2014 M3W.


I suspect that there are many people driving around with similar cracked brackets as it's not an area that can be easily inspected without removal of the alloy bulkhead behind the seats.

There is plainly a design issue here. Does anyone know if Morgan have modified/improved the design on new fuel tanks?

Here is the cracked fuel tank bracket after repair. I made up the repair panel from 2mm aluminium and bonded it over the original bracket with high strength polyurethane sealant [Bond-It 'Premiere' PU18]. The repair panel is larger than the original welded bracket so that it has a good broad mating surface with the original bracket tab, as well as overlapping onto the tank itself.


I think I have also identified why the bracket failed in the first place. The seatbelt type strap around the tank was quite loose. This is apparent in the photo below:

Look how the strap has worked itself to the bottom of the slot in the bracket. I don't think it could do this if it was correctly tensioned. Also, we found that the tank itself could be moved up and down a significant amount when measured at the rear of the tank (adjacent to the rear wheel). Centering up the strap in it's bracket and tightening the strap tensioning nut produced a tank that was rock solid. I would estimate that we tightened the adjuster by around 8mm of thread - which is quite a lot!

I'm confident that this problem has now been solved with the reinforced bracket and correctly tensioned strap. The take-home message here is that we need to be checking the fuel tank strap tensions when we do our other maintenance checks.

I had a reason to take the seat bulkhead out today and thought I had better check the fuel tank brackets. No big surprise that one of them is cracked. It looks like I will be doing your repair scheme Bunny, thanks for doing all the development work. I think that although only the RH side is cracked I will do the plate on both tanks, the PU18 is on order. The strap seems pretty tight on both tanks incidentally.