Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Ground clearance/underbody shields

The end of my drive is slightly raised and drops down to the road. This has caused some grounding issues 2 up as also happened in a car park yesterday on uneven ground. Looking under the car I see a shield covering the crossmember (right of photo) which is presumably meant to protect this area but the rear gearbox mount (assuming thats what it is!) has no protection and the bolt ends take the brunt of any impact. This area is much nearer the center of the car and therefor most likely to ground. Ok the shield is lower but nearer the front. I have found that by leaving the drive at a shallow angle I can avoid grounding. I'm just concerned about any damage that could be caused to the rear mount. Anyone else had this issue?

Edit : I should say 2011 Plus 4

Using 65 profile tyres instead of 60 will give you almost 1 cm more ground clearance.

I have 60 profile at the moment so makes sense. Unfortunately they are brand new ones all round. But probably a market for almost new Yokohamas!

The problem with shields such as yours is they further reduce ground clearance increasing likelihood of grounding. The solution I used was to fill the inverted U shaped cross member with a shaped hard nylon block attached with 6mm sunken bolts to same and sitting just a couple of millimetres proud of vulnerable edge's.

Richard's idea is great and easily replaceable when or if needed but I fitted the rub plate to mine as in the end the nylon block sits 6mm lower than the actual cross member and the plate sits exactly on the cross member and is the same 6mm deep. What I liked about the rub plate was that it gave a lead in face and a similar taper to the rear. If you were to hit something like a metal gate stop or a shear faced obstruction the car has, in my opinion a better chance of pushing over it without a total face to face impact area.

Thankfully I haven't needed to try this out for real but should the worst sort of scenario occur then I hope to limit somewhat the damage done. I bought my plate from Williams racing.... and guess what it wouldn't fit my car. Despite the many conversations and photo's sent I was assured it would fit by Williams, well it didn't, so I profiled it to clear the gearbox front and rear, this allowed it to sit correctly in the channel.
After some discussions on here with others having the same model as me, a plus 4 with duratec engine and MT-75 Ford gearbox, a conclusion was reached that the bends made on my plate were more acute than was normal or should I say should have been made. Wish I had known that as William's would have had it back!

Re. the gearbox rear mount. Look at Monty's posts, he raised his hugely and posted it here, I'm sure Dave will link it if he picks this up.
I too changed out my 60 profile yokohama tyres for 65 profile. This puts you in the VW polo tyre size and you can buy premium tyres for a lot less than the original fitment. For me it has transformed the ride quality and although gained what only seems to be a small amount of ground clearance you can visually see it! It seems impossible, but to say it felt like a different car is not just wishful thinking and has allowed me to sit behind the wheel for much longer periods. I also can't find any difference in the steering or handling and have pushed the car quite hard although I don't track the car where perhaps you might have some slight gain with a lower profile tyre.

The two bolts that stick down under the gear lever can be replaced with countersink bolts but turn them around so the bolts protrude upward, 1 is a bit fiddly but can be done.

I also have a driveway sloping down to the road. The only place mine catches is on the exhaust tailpipe. I have to reverse up and even then with the nearside rear wheel going first (if that makes sense)
I also have 65 profile tyres and haven’t had a grounding underneath since fitting. Surprising the difference that extra cm makes.

I also changed to 65 profile tyres last year on advice from others on here and have been very pleased by the improved ride comfort without seeming to have any noticeable impact on handling and I haven't grounded it in the last 5k miles since I changed the tyres.

If you haven’t seen it before, this old thread might be of interest. Lots of shenanigans going on down below…

Your shield on the underside is a worthwhile upgrade.
Mine regularly grinds on speed bumps but it’s nothing to worry about, it just lifts the car slightly as needed. It does protect that structural cross member and to some extent that vulnerable brake pipe too.

185/70/15 for me, never grounded out.

Thanks Rog, that looks just what I need. Is the bellhousing plate a commercial one or a self made? And just how difficult is it to get the nuts on the countersunk bolts on the rear mount? Doesn't look as if there is room to get a finger in there!

I took a more surgical approach

Bellhousing before



Bellhousing after





Crossmember before



Crossmember during




Crossmember after




Job done

All very nice. I don't do metalwork and I don't have a hoist unfortunately. It'll be axle stands and on my back for a while!!

The gearbox mount is now very much Monty's low point.



I've slowly been using the road surface to machine down the two protruding 'sacrificial' nuts as arrowed above

The tyre idea is all well and good for most, however, my plan to go up from Monty's existing 185/65 tyres to 195/65s will actually only give me 2mm of additional ground clearance. Changing my already machined down gearbox mount nuts to countersunk alen bolts adds a further 8mm, so a total ground clearance improvement of 10mm.

While 10mm doesn't sound like much, as others have suggested it's actually a game changer; however, I also have a pair of these to fit.....



Let's call them 35mm lower damper eyelet extenders, but with a 90 degree twist

To keep it all swinging with the natural rearward axle movement, Monty's rear Bilstein top mounts it will also get these eye to pin converters.....



The new setup should completely resolve any residual ground clearance concerns, while at the same time removing the dreadful binding/twisting loads that cause this sort of thing.....

Of course as many of us have learnt to our cost, those horrible twisting forces Morgan built into their ill-conceived telescopic damper conversion have the power to deliver far greater levels destruction than merely some accelerated bush wear.











Morgan's solution was to just keep making components like the lower damper mount stronger and stronger, until it finally stopped braking, as we can see below .



My thinking is it would be a far better approach to remove the twisting forces in the first place, in this respect it strikes me the below 'Rutherford telescopic damper conversion' actually got it right first time

Interesting, I had thought that the shocks were acting as involuntary bump stops by reaching the end of their travel before the suspension did....?

Be careful if you've got AVO's, if they bottom out it will break the internals and they WILL leak

My front AVO's as supplied by Cain did have internal poly bump stops I found.

Yes, fair credit to Cain as I think it was one of his re-spec upgrades to the new versions

A good set of telescopic dampers like my Bilsteins should have a bump stop on the rod, but these are really there to protect the damper internals.



I've actually temporarily replaced my original Bilstein ones shown below.



With a shorter set from Protech, I did this for more damper compression stroke which worked really well..



The true bumpstops on a Morgan are simply hard rubber blocks and work on the rebound, in my opinion they are nasty things.



I replaced them with a set of Triumph TR3 axle mounted bump stops, these were originally made from rubber and you can still buy them in rubber.



However, I went for the upgraded polyurethane type.



They gave me a bit more rebound stroke, and work great as part of my package of other improvements

I like the solution from Richard, but would not like to drill some holes in the crossmember..By chance I got a block of plastic used for curbing ribs on snow ploughs.

[img]https://ibb.co/MX0sCbg[/img]

[img]https://ibb.co/JwCmd9Xn[/img]

Neat solution Detlev but difficult to see how much the nylon is proud of cross member. Mine is hard 66 grade nylon block shaped to tightly fill the upturned U cross section and sitting only 2-3mm proud of member edges with tapered edges front and rear. Main reason for choosing the medium was it's slipperyness so avoiding transmitting too much force to chassis when in contact with road obstruction.

BTW holes make sheet metal objects stiffer and mine are only 6mm anyway. The mounting bolts are simply to hold block in place, it's tight fit taking all the force.

A bit fiddly but not that difficult to replace the nuts/bolts on the rear mount. You can get a swan neck spanner in there. If you are counter sinking the holes with just axle stands, make sure you have a good pair or wrap around eye protectors.

The bell housing plate is my own homebrew bodge.

„ … section and sitting only 2-3mm proud of member edges with tapered edges front and rear“ - that‘s what I did, Richard.
End of August we will go to Danmark, the first test …