I have been driving the 3 wheeler out and about over the last couple of weeks and the car has been gradually pulling to the left more and more. Today a loud knocking appeared from the front of the car, on inspection i found the top mounting of the the upper wishbone was catching on the bodywork, it was then i noticed the crack on the chassis just behind the top mounting, i checked the other side and it is also cracked! The car has had the bolt in reinforcing bar since 2014 and the lower strengthening plates in 2018 so i would advise anyone who has not had the 2014 chassis upgrade to check their cars regularly as it seems the bolt in bar does not provide a long term solution, my car has done approx 11k miles. I have sent messages to MMC and i will report back on the outcome.

You should maybe add that your car is a 2012 one with its original chassis, the very early type without the small gusset plates in the corners. How many miles have you done since you got the car Hugo? I only ask as we both had a very close look at the chassis when you got it, then again when the lower wishbone mount cracks were discovered, only to find them cracked on your car. I would assume that MMC would have checked the chassis again when it was with them for the suspension point strengthening mods in 2018, not many miles ago. These cracks can obviously appear very quickly.

This is appalling but thankfully you spotted the problem and averted what could have been a disaster. I trust you are safe now.
As you will see from this forum, chassis cracks have been a major issue with these vehicles so please keep us informed on progress with the repair.
Good luck

Good point...

Ian
Thanks for the additional info, the car has done about 3k miles since it was last inspected by MMC,

This begs the question:- "How long will it be before someone is killed or badly injured by faults such as this?"

I have recently sold my 2013 car with 19K+ miles on the clock and I have to say that although it was great fun to drive and I will surely miss it, they do certianly live up to the claim in the original MMC advert that "every drive would be an adventure".
Every time you went out for a ride, it was debateable how you would get home, i.e either in one piece, on the back of a pick-up truck, in an ambulance or in a wooden box.
Given the cost of these machines, there is no excuse for life threatening faults such as this, as a result of design faults and/or use of poor quality or incorrect materials and lack of proper development.

Having said that, I do miss my M3W.

Hugo,

When was your machine built? I.E. what chassis/ unit number?

General forum: Is there any data on the dates or chassis numbers most vulnerable to cracking? Certainly not all early chassis crack, so am wondering if this a fundamental design issue, material issue, or quality of welding issue.

That's a very good question...

It sounds like this is an example of an early 2012 chassis with the bolt-in brace together with the more recent extra gussets - the crack described seems to be the one the bolt-in brace was designed to prevent and begs a question on whether the brace is an adequate solution for an early car where a crack/cracks may have initiated but not propagated. From this one asks how many cars with the original (hopefully braced) chassis are still out there...

We were "lucky" in that our v early one cracked and had the chassis replaced