Hi all, wondering if anyone out there that is running 793F's has had engine failures due to bearing issues ? This is in the C175 Generation 1 engine, there is an accepted fault that Caterpillar acknowledge and fix is to do a bearing roll in at 6000hr intervals, and then change out engine to a generation 2 at overhaul time, which is obviously a pain, but at least Cat have been up front about this and are doing something about it! Our problem is that we have had a couple of engine failures before the bearing roll in was due, would like to know if others have had similar failures, as we have 58 of these running around and want to guage how big an isue we are facing? Thanks
Heard all sorts of C175 horror stories but no practical experience I'm afraid. What oil change intervals are you using..?
Hi Nige, we stick to 250 hrs intervals, SOS results always good, so no early warnings of a problem ...
Well that answered one question, so I'm going to have to dig deep into the barrel for this one. Try sampling some engines at 125 hour intervals and plot the trend for lead and possibly tin as well. I've seen cases where engines got contaminated with coolant where it literally destroyed the top surface of LTO on the crankshaft bearings and trending the lead was a way to detect it. What you'll likely see from Day 1 on a new engine is that lead will be going along happily at either 0 or 1 ppm and will suddenly spike to maybe 4 or 5 in one sample. The next sample it will be back down to almost where it was before but not quite. A graph shows it clearly. So if it was 0-1 before it might possibly go back to the 1-2 range. The spike in lead plus the fact that the numbers never quite go back to where they were before the spike can be a clue to the fact the LTO is disappearing rapidly from the bearing shells. I would say it's worth a try if it saves even 1 engine.
Maybe this is part of the reason I've been seeing 793F trucks being hauled to Cat dealers, the word I heard was some fairly major chassis cracking but this sounds like another issue too.:beatsme
Yeah, the Chasis Cracks is another issue with a lengthy procedure to fix, so far we haven't seen any major cracking in our fleet - but early days .....................
Currently I am at a site in the Pilbara, NW WA where there are about 45 793Fs running. I thing that the early ones all had bearing problems too. Also heard that Cat are going to supply 2 extra trucks while the whole fleet get taken back to Perth to have a chassis upgrade done 2 at a time. Going to take a while to do the fleet though! At least these problems are getting attended to by the dealer.
How about the electronic thermostats? they where causing grief first up, I am no longer involved with these trucks so just wondering wether Cat went back to old style thermostats or have kept on with electric??