Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Extra ground clearance on a Mazda boxed +4

Thanks Rog,

I'm now thinking 'lowest and first to strike a speed bump' could be two different things due to differing approach angles and distance from the front axle line. The only way to know for sure is to get Monty over my pit and check for whitness marks, it sounds likely the point of interference with the highest of speed humps will be the the bolts podtruding from the MX5 gearbox mount so I'll need to implement your countersunk alen head solution.

The offending speed hump that helped find Monty's ground clearance limit was tackled again yesterday, but this time without a passenger, driving solo the car traversed the unusually high obstacle without any grounding at all, so we're probably talking about just a few millimetres. However exiting the field at Kop Hill did provoke some scraping sounds so it definitely needs looking at, however, to be fair the soft soil exit was very heavily rutted so presented some unusually abrupt and acute angles for all low and short wheelbase vehicles leaving the event.

Yes worth checking underneath for bent bolts, particularly seat where MMC delight in fitting over long ones. Suggest removing bent bolts immediately if you can as nut will get progressively more difficult to unscrew on thread. I gained about 15mm more clearance by correcting protruding threads.

I'm pleased to say my grounding out incidents have been limited to one day where I traversed two unusually high speed humps in quick succession, it needs addressing but it's a long way off enjoyment limiting, or urgent to resolve.

I say this because I'm just back from another epic and very spirited roof down night time drive, with passenger, and there were zero issues or odd noises... other than the squeals of joy from the seat to my left

At 143hp my Morgan is definitely the least powerful hobby car I've owned, and by some considerable margin, but Monty is also without doubt head and shoulders the most fun

Good point Richard. Definitely worth sawing off the four seat bolts in the rear cross member. Why they ever leave them like that….

There was much rain last weekend and it washed out a short (50m) gravel road I used to pass without problems.

But now I (Plus4 2019) run over a bump with wet loose muddy gravel. The heap was pushed away by the crossmember and the bellhouse. See Pic 1, Front is on the right.

Pic2 and Pic 3 show that a part of the bellhouse that was cracked away. Fortunately no further damage visible.

The rear gearbox mountig arrangement was filled with gravel too, but no damage there.



mog1 by Werni Wehrli, auf Flickr

mog2 by Werni Wehrli, auf Flickr

Mog by Werni Wehrli, auf Flickr

Ouch! Sorry to see that you have cracked your bellhousing. That must have been quite a whack

I echo Rog's sentiments, nasty business that

I wonder if the lower section of the bell housing can be removed, its just hanging there with no fasteners connecting it to the sump or engine block, I'm almost reaching for my 9" cutting disc

Equally, there may be scope to reshape that crossmember and then re-strengthen it to retain or even improve its structural integrity, this while gaining significant ground clearance

These are radical solutions, but surely they're the only truly effective solution to the problem?

Sadly I have to confess to sitting under the car contemplating this with a cup of tea

Like you the thought of cutting the bellhousing casting off was tempting but that would leave a gaping hole exposing the clutch. Not ideal so some sort of semi sealed cover would be needed. All a bit too hard so I swiftly gave up on that and decided to just fill the step with my solid block. The cross member is equally awkward. Replacing it with something that has at least the same structural integrity would be very difficult, there’s so little depth to play with. Butchering the cross member to reduce some of its depth is a definite ‘no no’ too as that would remove critical strength. There is little scope to raise it either. The cross member sits quite close to the Mazda box anyway and you also need wriggle room should the box ever need to come out. All a bit impractical so took the easy route again hence the skid. One thing I did do re the skid was to thread the cross member for the fixings rather than use nuts. As said there is little room and the nuts might just interfere with the gearbox as it shakes around on the mounts.


But there is of course a very simple solution

Just change to a pre 2011 +4 with a MT75 box

But the Mazda box is a wonderful thing Rog!

It's so nice to use, for me it's one of those tactile elements of the car that makes my Morgan such a rewarding driver’s car.

Like the joyus mechanical clunk when you release the handbrake, the Mazda box is something I'd never remove.

I firmly believe it's one of the best manual transmissions ever designed, only a Honda S2000 box rivals it.

I added a skid plate today. Not as elegant as Rog's fix, but will do the job. It's been waiting on my to do list for quite a while. I added a piece of leather inside just to stop the metal to metal contact.