At 4000hrs, the viscous cooling fan hub was replaced on my Cat 324D, under warranty. At 8000 hrs, the fan has disintergrated, sending fan blade material into the water and oil rads, necessitating replacement of the rads, fan, viscous hub and sensor system. Ouch! Upon close inspection of the hub, there is a small bearing on the radiator end, then a plastic sleeve? (hard to tell, cause its broken).The bearing is siezed solid and very dark in colour. We think the bearing has siezed (dry bearing, overheated?) causing the sensor system to fly off into the fan blades. Has anyone had similar experience. Am I on the right track? If so, has this been impoved on my other D series machines, or do we need to check/replace that bearing. Other macines are 320DL 320DFM 325DFM 336DL. Appreciate your imput.
First some important questions: - 1. What is the machine S/N prefix..? 2. Do you have some good photos of the failure? If so please post them here. If you want to post the S/N prefix of all the other machines that you are asking about then please do. Mods - you may want to move this post to the excavator section.............
Yeah this thread is better served in the excavator section.
Will get photos and serial no's.
Never seen any failure's like that here and looking through our systems doesn't indicate it being a problem either, only failure mentioned is an electric issue but nothing about the bearings in the hub, I think you just had bad luck. But do go ahead and check your other machines, better safe than sorry.
Log frog - just so you know. Per's the expert on here regarding Cat excavators .............
Really? I've seen people on the forum that seem to have been around the block a few more laps than me.
Fan belt tension is critical. I have had fan hub, water pump and alternator bearing failures due to over tightening. I'm admittedly a slow learner. Follow manufactures instructions. Or, just tighten enough so you cant pull fan unless you really reef on it. Wear gloves.
If fan pulley squeals for more than 1/2 a second when revving engine, tighten a tad more until you hear only a chirp. Squealing on shut down is okay but only a chirp is all you should hear. If all else fails, pulley or belts may be worn too far. I switched to pure synthetic grease. Runs cooler. Cooler is good. Hope this helps.
Now you've really got me digging into the past. Okay: regarding fan hub bearings. Do not apply more pre-load than what man. states. If no manual available, tighten only to about 25 to 35 inch pounds. Do not run with slack bearings. There has to be a tad of pre-load and use the synthetic grease but do not pack the hub full as this causes heat which will kill the bearing. The expansion of the grease may push out seal if packed tight. It's amazing what a difference synthetic grease makes. Good luck.
Sorry about the delay guys. Here are the photos of siezed bearing, and resulting fan damage. Other machines I have concerns about are: 320DFM GKS0021, 320DFM GKS0271, 325DFM C7K01453, 336DL WRK00253, and 320DL ETAE00111. Thanks in advance for your time and trouble.
That fan blade is really something. If I was you I would make a clock out of that and hang that on my office wall. Be really neat if you could find a clock with the CAT logo to place inside the center. I bet some someone into art world would pay big bucks for that blade to use in a sculpture. I defiantly wouldn't throw it away. You might try listing it on Ebay in the art section..
The rads are even more impessive, very artistic with a Swiss Cheese effect!