Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Clanking sound coming from rear. Any info?

I have about 500 miles on my 2016 M3W. I have been breaking it I slowly since the winter.

Yesterday I started hearing a clanking type of noise coming from the rear of the M3W, near the rear wheel. It sounds like metal pieces lightly banging together.

The noise may have started after a hard acceleration I did when I pulled onto the parkway last week. I chirped the rear tire shifting into second gear, and heard the same clanking noise. Now that clanking noise happens when going over tiny bumps or any time the chassis flexes.

Any idea what it can be? Hopefully nothing is broken! If I actually damaged something by accelerating hard and chirping the tire while shifting into 2nd gear, I would be very disappointed at how fragile this machine is!

If any of you know what this could be, I would really appreciate your input.

I prefer to wait till I clock 1,000 miles before I take it to the dealer, which is about 100 miles away from my home.

The centre pivot of the swinging arm and the centre of the output shaft on the final drive (bevel box) share the same centre. When your driving normally the top of the belt is in tension being pulled by the bevelbox drive pulley. Under very light load if you go over the bump the swinging uarm comes up and has the effect of unloading the belt which causes a backlash noise from the BB. It's the same noise you get at very light throttle and you go from drive to over run and back to drive. If this is the noise it's completely normal and you get used to ignoring / driving with it.
If it's not this, when is the noise at it's worst and when is it gone. This will give us a clue. The modern cars are generally pretty robust - you won't have damaged anything I'm sure. You will get used to these noises - generally if it's still going it's not broken. The noises and rattles will probably change and come and go every time you drive it, it's the wood / aluminium / steel chassis and a big lumpy engine all creaking away - bit like a big sailing ship - you just get used to it. Just enjoy

An excellent response. I will take it further down the road and say that as long as you are hearing noises and they don't get too robust then all is good. When, all of a sudden, a certain noise disappears then I check the rear view mirror to see if parts are on the road behind me! The odds of something suddenly behaving and acting quietly for no apparent reason are so remote that I have given up hoping for that and I just assume that some other trickery is in play.

Thanks for your responses guys. The noise can possibly be coming from the bevel box and it may in fact be the swing arm, but I never had this noise until yesterday and it started soon after that initial clanking when I "banged" it into 2nd gear under full acceleration. It was during that shift that I heard the same noise....it was quite a bit louder though and it almost sounded like something snapped. I was also under full throttle, so the belt drive must have been at full tension. I also currently hear the sounds while accelerating.

It sounds like something came loose, but I jacked the car up and checked below and i didn't notice anything out of sorts.

I know the M3W is quirky and generates a ton of strange sounds, but this is one that is beginning to worry me.

You could try removing transmission tunnel and looking for any metal to metal contact, particularly bevel box touching chassis for example. Sounds like something has slipped or (hopefully not) broken!

+1

Hi polar993,

Is the belt tension still OK and is the rear wheel still aligned? Could the rear wheel drum brake shoes have come loose? Honestly, I would flat bed it to your dealer.

The tension on the belt is normal and the brake shoes do not appear to be loose or damaged. I was on able to visually inspect the bottom of the car by jacking up the rear and taking a peak. Nothing seemed out of sorts.

The car drives normal and doesn't feel in any way loose, but the sound is a bit worrisome. I wish my dealer wasn't 100+ miles away, otherwise it would make most sense just to drop it off and let them inspect it.

I hate to give up any precious summer driving time, but I also don't want to run the risk of causing more damage to something, or putting myself at risk by driving it if it's unsafe.

I'll see if I can take a video to capture the sound it's making. Obviously it's not going to be easy to do with my Stage 1 kit and wind noise but I'll try....

Thanks guys!

-Tom

If you haven't already remove the rear boot liner for a better visualization of everything in the rear from the top.

About a week before I sent mine in for a check engine light I heard a noise coming from the back as I decelerated at low speed. Turned out to need the wheel bearings replaced. Dealer said manufacturing defect on those. It was more of a clunking than clanking though. I've needed wheel bearings on other vehicles and never had a noise like that though. Don't know if that helps.

Might have even been at around the same mileage as yours.