Gregg and I had taken the car out for the evening, and on our way home I gave her the beans around a fairly tight corner leading on to the M27. At this point I thought I had hit the rev-limiter as there were some odd sounds coming from the engine so we slowed down a bit. It was then that I noted things were not quite right.
The air-con wasn't "con"-ing any-more... the battery light was on, and the power steering was incredibly heavy. Something had broken. Crap. The good news was that the engine was still running so we decided to get the car home (about a 15 minute drive) and then try and figure out what had happened.
On first inspection it looked like the power steering and alternator (including aircon) pulleys had jumped off the main crankshaft pulley, but after a closer look the actual pulley itself had broke in two.
GTOs have an interesting feature in their crank pulley, basically it is a two-part construction. The inner solid pulley, a rubber spacer, and then the outer pulley. The spacer is a vibration suppression mechanism, but unfortunately after 22 years the rubber tends to perish meaning that the outer pulley comes loose.
By all accounts, this usually ends in disaster when the loose part penetrates the cam belt cover, breaks the cam belt and the engine destroys itself. Not only were we were lucky this didn't fail like this on this run, but also spectacularly lucky it didn't fail in Europe as we would have had zero chance of fixing it while we were there.
So the problem now lies with what to do. Due to its complex design, a replacement pulley can cost upwards of £400, plus fitting. This is crazy for a simple pulley. BUT... after some research, it seems that there are alternatives on the market. Specifically the 3SX lightweight crankshaft pulley:
found here Not only is it almost a 3rd of the price of the official Mitsubishi one, but being milled from aluminium billet, rather than steel, it is significantly lighter. Removing this weight from the crankshaft apparently can net up to 10hp. Bargin. So that gets ordered, along with the two belts. But the problem was fitting it. Research suggests that the crank shaft pulley bolt is the single tightest bolt on the car, and if you don't have an air-gun your are "gonna have a bad time". Well we didn't have access to one, so this meant we needed to get the car to Mitsiart to fix-er-up. While the car was drivable, we ran the risk of the outer pulley still destroying the cam-belt, and this would be bad so we needed to get that off and out of the way asap. Easier said than done.
Because of the way that the rubber had failed, there was no way to pull the outer pulley over the top of it, and the rubber was still bonded to the inner pulley. The only option was to cut away the old rubber to make space for the outer pulley to move.
My other half, Emma, gladly offered to do the destructive work. So I set her loose with a few tools and sharp implements.
Below is what the inner pulley looks like without the outer part attached.
The car can now be driven to MitsiArt, ready for installation of the new belts.
