Saturday 14 September 2013

Alternator Upper Bracket

Whilst on the return from a Southern Kit Cars trip to Bletchley Park, I thought I could hear a metallic rattling when the car was idling at junctions.  When it was safe to do so, I pulled up at the side of the road and took off the bonnet.  I discovered that the upper alternator bracket had failed.


Thankfully, the new bottom bracket is very robust and bolted up very tight.  This single bolt was holding the tension in the alternator belt.  Aside from worries about the alternator not charging, I was concerned that if the belt started to slip, then the water pump might not function correctly, with the engine potentially overheating.  For the rest of the return trip I kept to a steady speed on the main roads.  I made it back home, where I was able to look at the bracket failure in more detail.  It can be seen where the failure started, from the outside rusty edges and then it has spread across the middle, to completely separate.


For a replacement, I fabricated a new bracket out of a single thick piece of L-section mild steel.  It is a little overkill, but I really don't want to have any more alternator bracket issues.  Even if I'm carry just that little bit more weight than is necessary.  In the future I may trim off some more of the excess metal.


Tuesday 3 September 2013

Engine Mount Strengthening

The offside engine mounting plate is fixed to the chassis spanning two chassis rails, where they come together in a vee shape.  This is strong enough to take the loads transmitted from the engine.  On the nearside however, it is a very different story.  The flat plate is welded on top of just one chassis rail.  Over time the loads from the engine cause this to droop and eventually this puts an abnormal loading on the engine mount itself, which then fails.

I'd kept an eye on my nearside mounting plate over the months and it had always been fine.  Recently though, I noticed that the non-welded side had drooped around 10mm.  It was on its way to causing the engine mount to fail.

So, I fabricated two triangular fillets from 6mm mild steel and got a local garage to weld these in place, after 'jacking' the plate back into its original horizontal position.  The welds are not the neatest in the world, but they seem to be good enough to be strong.