Thanks, everyone. I guess my position on this is that, if Cat made it greasable, and accessible, and put greasing that component on the maintenance schedule, then I can see how I might be responsible. But since their design is not even maintainable, then it should last the life of the engine, or certainly the warranty period. As soon as one if these parts lasts for five years or 100,000 miles, then I will be content that it is my problem. Until then, I will press the case that it is a suspect design, if not defective, and it should be Cat's problem to resolve. We'll see how that flies.
I'll have to respectively disagree with you on the out of balance thing if it is factory, but my experience is anecdotal.
My situation happened about 5 years ago. My rig had about 14000 miles on it. I was headed from So Cal to Flagstaff the first week of December. I lost the belt as the when the bearing goes, the pulley loses it's base and wobbles crazily, cutting up the belt until the belt rips apart. I lost the belt about 70 miles west of Needles, at 10:30 at night.
I didn't see it coming as I had no warning like a hum, vibration or any other sensory clue. My first warning was a Christmas tree of lights also known as my Freightliner dash, due to overheating. Losing the belt caused an overheat. Since it was at night, I was watching the road more than the dash gauges.
Anyhow, I was able to pull off immediately. I grabbed a flashlight and through the let rear cabinet door I could observe the rear section of the engine. I saw the belt broken and hanging there and pulled it out, followed by a call to Good Sam Road Service. They got me a big rig tow out of 29 Palms and pulled me to the rest stop 30 miles to the west of Needles. Apparently, that is the closest they can tow to Needles for side service.
Brandt Ranchers, and Bailey, the Golden, too!
'05 Expedition 37U, CAT C7/Allison 3000MH
'04 Jeep Wrangler Sahara
Life Time Good Sam Member
Next morning, I got up extra early as GS service is back east, got a rep on the phone and arranged a repair facility to come out. They called me to get early info on the repair. I told them the belt broke. They asked me to turn all the engine accessories and report back to them any that didn't turn. They suspected a seized alternator or pump.
Turns out, when I hand spun the fan blade, it wobbled like crazy, indicating the mount or bearing was busted.
They surmised that the problem was most likely a bad bearing and would come out with a belt and remove the mount and bring it back to their shop for repair.
Sure enough, they removed whole fan, mount and checked the bearing. It was shot. They did the removal from the floor of the rear wardrobe floor using a 90 degree air powered tool. No need to remove the radiator.
Anyhow, after many hours, they fixed the bearing and mounted the whole assembly back onto the rear of the engine, popped on the belt, and did a test run of the engine. Everything was working peaches.
Bill was about 1700.00 including parts. It may seem steep, but this was 10-12 hours of work, the repair place did it roadside, and they were driving back forth from Fort Mohave.
Roughly 250.00 of the bill was the part, the bearing.
Here's where it gets interesting.
The mechanic when trying to order the new bearing from CAT in Kingman, was asked if he wanted the one piece bearing or the two piece bearing. Apparently there is a newer version that CAT recommended. I can't recall now if it was originally a one piece being replaced by a two piece or the reverse, (I believe it was one piece replaced by two piece) but whatever they used has now lasted an additional 30000 miles.
* This post was
edited 04/06/12 08:21pm by brandt ranch *
One more thing to check. Was the serpentine belt replaced when the first pulley was replaced and was it the correct length? It is entirely possible to put a serpentine belt on that is to short. If the belt is only 5mm shorter it will dramatically increase the load on the components. I learned this when the vehicle line I worked for made a slight change in idler pulley location which required a longer belt. Unfortunately the parts side of the business was not informed of the longer belt requirement. Suddenly we had cars destroying A/C compressor clutches, the weak point, after belt replacements. The cure was the correct, slightly longer belt that engineering neglected to inform the parts division about.
Randall, that is something that would be good to know. I gave the Cat dealer the broken belt that was on the engine. I expect that it was a new one back then, and I expect the right size. But who knows? I will ask the service manager to check that. Maybe it will give us a lead. Thanks very much!
I do not have the parts numbers for either the sealed or greasable bearing housing/bearings (we are on the road).
But, call the Caterpillar RV hotline 877 777-3126 or any dealer with your engine serial number and they should be able to give you either/both part numbers.
Not sure finger pointing will do anyone any good, but the engine maker does NOT tell the chassis maker how and where to mount the CAC and radiator (and therefore determine ease/difficulty of accessing the fan hub).
Foretravel choose a side mounted radiator and CAC on our coach, so assess to the bearing is very easy-- a 10 second operation. Other chassis makers choose the less expensive rear mount radiator-- access to a LOT of things is a lot tougher. But, I have never seen anything from Caterpillar or Cummins saying that a cooling package or coach "house" should be mounted so the engine can be easily accessed for work. Heck, I have seen coaches where the top of the engine could only be accessed through an 8" by 8" hole in a closet floor. Even removing the valve cover to adjust the valves would be a half day operation.