VCCA Home Forums GENERAL DISCUSSION Meets, Tours & Events Southwest Fall Tour

To my friends on the Southwest Fall Tour,

Thanks to Dean Echols for organizing another great Southwest Fall Tour, this time to Heber City, Utah and the surrounding area.

Some of you may have been aware that my blue 1940 pickup developed a troubling drive train noise during the tour. It sounded like a bad bearing, and was noticeable only in high gear at low loads and low speeds (below 40 mph). I was concerned enough about it that I was seriously considering making arrangements to trailer the truck back to Reno. In the end, after some testing and evaluation, I decided to drive it home.

I left the Homestead Resort at 4:00 a.m. on Saturday in a drizzling rain and utter pitch-black darkness. It was a white-knuckle drive from Heber City to Salt Lake City--not because of the truck but because of the terrible driving conditions. Only the sealed beam headlights and the vintage Bosch 6-volt windshield wiper motor that I retrofitted made the drive possible. The cab was kept warm and dry by my Filling Station windshield rubber seal (thanks, Steve), and by the 1940 heater/defroster unit. It was about 42 degrees at Parleys Summit on I-80. The rain increased as I dropped down into Salt Lake City, and the traffic, mostly trucks, increased as well. The glare from their on-coming headlights and the splashing water from their wheels posed a real challenge, and I had to hold my speed to about 45 mph.

Once I got safely through Salt Lake City and headed west on I-80, the rain stopped and I was then able to pick the speed up to 60 mph. The truck was running great, with no abnormal noise from the drive train, though my nerves were on edge, listening for the slightest noise that might indicate a problem. But, the truck kept humming along, and at 2:00 p.m., I turned into my driveway and heaved a sigh of relief, having completed the 570 mile trip in 11 hours.

I spent the day today disassembling the drive line, and to my dismay, I have found nothing wrong. The transmission looks good, the rear end looks good, the propeller shafts turns free and smooth, with no axial play, and the front propeller shaft bushing is tight, with minimal radial clearance. I thought maybe the pilot bushing in the rear of the crankshaft had failed, but it looked like new. I started reassembling everything, but now I think maybe I better extract the propeller shaft so I can look at and feel both of the pinion bearings individually. I suppose it's possible that the forward pinion bearing is going bad and I can't feel it by turning the propeller shaft by hand with it installed in the torque tube. I'll write a follow up post when I find out what the problem is.

Meantime, I hope everyone had a safe and uneventful trip back home.

Mark

Instead of reassembling after finding no obvious cause of the bearing noise, I decided to go ahead and pull the propeller shaft from the torque tube and closely inspect the pinion bearings. The first photo below shows what I found. The ball separator ring from the rear row of the forward pinion bearing had become distorted and came apart from the bearing, allowing the balls in the rear row to bunch up.

The second photo shows the eight balls of the rear row bunched together. The other three balls visible are from the front row and are still being held in place by their separator ring.

The third photo shows the front side of the forward pinion bearing with its ball separator ring still in place.

Surprisingly, there is no damage to the bearing races or the bearing fit on the pinion shaft, and, in fact, the bearing still turns freely and smoothly, which explains why the propeller shaft rotated smoothly in the torque tube prior to disassembly.

My guess is that a small piece of debris got into the bearing and one of the balls tried to stop, which caused the bearing separator ring to distort and come out of the bearing. The intermittent bearing noise I was hearing during the tour was probably dependent on how the balls oriented themselves in the bearing.

Had a piece of the ball separator ring broken off and got into the bearing, which seems like a more likely scenario, there probably would have been significant damage to the bearing, the pinion shaft, and possibly the bearing bore. I was extremely lucky to have made the 560 mile drive home without disaster. As it is, it looks like all I need to do is replace the forward pinion bearing and reassemble.

Mark


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Mark,
It sure was great to see you again. The tour was spectacular!!!!
I would go back there again. Next time would like a couple of days to muck around the Erickson collection while the ladies shop in Park City.

Sure glad you got home without further problems and found the source of the noise. I suspect that very few would have heard the noise and/or done something about it until it got much worse. I am likely one of those folks.

Chip,

It was a real pleasure seeing the Southwest Fall Tour regulars again, as well as meeting new people, all enjoying their Chevrolets.

I really enjoyed the Erickson collection and could have spent days there, though my enjoyment was hampered by the cold weather. In my old age, I really don't do well in the cold. I'm thinking of a possible return trip next June when they're open to the public over one weekend.

I'm hoping I can make next year's Fall Tour, as I'm sure it'll be another great one.

Mark

This is really good tech info that I think should be preserved in the tech forum too. No doubt others could use it, but may not see it here. Perhaps the double posting policy could be "winked at" this time?

I would suggest completely disassembling the rear and checking or replacing all bearings if you have not already done so.