Measuring bearing clearance with Plastigauge

[Stretch]

I thought I'd show a bit of work I've been doing recently that I hope will encourage others to do the same if they need to: Or at least be able to understand what a mechanic is doing if you decide to let someone else do this for you.

This thread is aimed at the inexperienced or the wary – I want to show that it isn't difficult and it isn't some sort of Black Magic art.

Plastigauge is cool stuff. It is used to measure very small gaps between machined parts where it is difficult if not impossible to use any other means.

The pictures below show my OM617 diesel engine in bits. I'm checking the big end shell bearings to ascertain the amount of wear before taking the block off to the machine shop for a re-bore – I hope I don't have to take the crankshaft too!

(I've already removed the engine – all of the ancillaries – the transmission – the cylinder head – oil pump - and the upper and lower oil pans. The pictures show the engine in an upside down position)

The information in this thread is nothing new – it is essentially just a copy of the instructions on the Plastigauge packet together with some photographs.