Caterpillar G3516E counterweight bolts

Experience Vs Instructions

Knowledge Base


Once again this week, I’ve been reminded that you can’t always depend on the manufacturer’s manuals for all the information you need.

I was on-site, installing new main and conn rod bearings on a land-based Caterpillar G3516E power generation engine.

I consulted the manual and noticed some important information missing.

The first was when I came to remove the bearing caps.

What the manual fails to mention is that in order to remove the main bearing caps, you must first remove the counterweights.

Failure to do so makes it impossible to access those bolts properly with the weights fitted.

(Although there is a special tool to do so, we still ended up taking the weights off to get the best possible access)

The bolts are twelve-sided, usually denoting that they would be high tensile and suitable for re-use, but not according to the manual, which states that they must not be reused and need to be replaced with new bolts.

Crankshaft counterweight bolts(1)

Carrying on through the workscope, the manual also states that the removal of the oil pump is required to access the main bearing caps, but again, fails to mention that other items also need removing, such as the oil coolers and oil filters for example.

These omissions may seem minimal, but they translate to an extra 2-3 hours of work and mean that the job cannot be performed by a lone engineer.

In addition, new gaskets and seals will be required to re-seal these items when they are refitted.

I just wanted to share this to highlight the importance of experience over a textbook, and if you have any concerns or questions on work due or an issue your engines are experiencing, please let us know – we’d be happy to help.

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