Tuesday, June 23, 2009

Losing our bearings

We are at the scenic overlook
and visitor center south of the Perrine Bridge in Twin Falls, Idaho, with a view of the spectacular Snake River gorge (map).

Our directory indicated that overnight parking was allowed here at the overlook, and a quick stop in the visitor center confirmed that. In addition to free parking for the night, there is an Outback restaurant right next door, a Johnny Carino's next door to that, and a shopping mall across the street. We had a nice meal at Carino's, with a full carafe of wine to wash away our troubles.

Those would involve bearings. As we pulled in to the overlook after a long run, we noticed quite a mechanical racket. At first I thought it was construction machinery -- there is a construction site a couple doors down, and the road south of here was also down to one lane for some kind of maintenance. But when we shut the engine down, the noise went away, replaced instead by a sinking feeling in the pits of our stomachs.

Back at the engine bay, we quickly determined that the noise was coming from somewhere in the neighborhood of the radiator fans, which was a big relief to me, because that meant it was unlikely to be a problem with the engine itself, such as a bad lifter or a problem with the cam gear train. But it sure sounded like we were not going to make it to Salt Lake with whatever was causing the noise.

On the bright side, we're in Twin Falls, which is what passes for a major city in these parts. Earlier in the day, we had contemplated stopping for the night along the 1000 Springs Scenic Byway, which we visited on our last pass through this area, and that would likely have meant a catastrophic breakdown somewhere a long way from help -- either on the byway itself, or well past Twin Falls, depending on when we noticed the problem.

In fact, we had made several stops today, the last one being just 90 minutes or so before pulling into Twin, and we had noticed no unusual noises (the racket was quite noticeable as we pulled into the overlook, once we came down from road-level noise to idle speed). So the failure happened within the last hour or so of driving.

Once everything had cooled down, I was able to get the fan belts off, and the origin of the noise became completely evident -- the intermediate drive pulley that transfers power from the engine, on one belt, to the two fans, on a different belt, was quite loose. When I removed the hub nut, I discovered that both ball bearings had completely disintegrated -- about half of the balls were reduced to powdered metal, and the retainers and seals were just so much twisted metal. The damage was so extensive that there is no way to put the hub back together -- we are stuck right here until I can get some bearings.

The good news is that these seem to be a pretty standard bearing (a 6305-LL for anyone who cares), and I am hopeful that the lone bearing shop here in Twin will have some in stock (it was too late to call today by the time we stopped, around 5:30 MDT). If not, I am pretty sure that I can get a pair overnighted to us, which would get us back on the road Wednesday, likely in time to make our conference in Salt Lake Wednesday afternoon -- it's about four hours by freeway from here.

I can't free the inner race of the inboard bearing from the shaft, and I suspect I won't be able to press the new bearings (assuming I find some) in, either, so I will likely have to take the pulley and shaft in to a machine shop to get this done, or else hunt around town for a bearing puller and rummage through the parts bay to find some scrap to use as a drift.

I'm just thankful that we discovered this problem before it morphed into catastrophic damage elsewhere in the engine bay. The bearings are probably easy to find, but replacing one of the weird fans or even a Neoplan-specific fan belt would be a challenge, and likely mean a stay of several days here.

We did have a lovely drive today, departing the Interstate just over the state line for US-95 south, which took us to Idaho 78, bypassing Boise and some 110 miles of freeway, and reconnecting with I-84 in Hammett. Our decision, after much rumination, not to divert onto US-30 at Hagerman for the scenic route past the 1000 springs proved to be prescient, and we instead remained on I-84 to Jerome, where a wreck on the eastbound side had the freeway nearly stopped, and we bailed off onto local streets the rest of the way to Twin.

I expect to be too busy in the morning to post again, as I will be scrambling to find my bearings, so to speak. (Although I am hoping Louise, who took several photos of the damage, will add them to this post then.) With any luck, we should have the bearing issue resolved by the middle of the day, and either be on our way to Salt Lake at a leisurely pace, or begging the visitor center for another night (and an address to give FedEx) while we await bearings from afar. In either case, I will try to post an update here tomorrow evening.


  1. Sean you are an expert in finding obscure parts in obscure places. I'm sure this will be no different! Good luck with your repairs, and making your meeting!
    Rod Ivers

  2. Good luck finding your bearings!

  3. May the bearing God's be with you!!

  4. I envy your 'mechanical' abilities even though the events can happen at the worst times. Hope all works out well for the both of you.

    As always, enjoy reading your blog.

    Mark G.


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