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At the Gathering at Gilmore meet last weekend there were two failures of the fan hub bearing on our member’s cars.
One on a car being driven to the Gathering, and one on the tour on Saturday.
The fan hub bearing is a long bushing on the ’29 and later engines. This long bushing rides on the shaft we can see between the bearing assembly and the eccentric mount on the front of the engine. The hub has a round reservoir to hold oil to lubricate the bushing. This reservoir does not have a typical seal. It has a gap between a slinger [rotating round ring] and the shaft.
When the reservoir is filled, the oil level will be lower than the gap between the slinger and the shaft. But the internal parts do allow some oil to get on the shaft and past the gap and then all over the engine and underside of the hood. The slow inevitable loss of oil can catch us, the car owner/driver unaware.
The fan hub bearing’s oil level cannot be ‘checked’, it can only be filled by the normal process. Since this is a bit of a bother, most of us don’t fill it very often. And unfortunately, this leaves the bearing without adequate lubrication and eventual failure of the bearing.
For many years, a lot of PAS members have had their fan hubs modified to use modern, sealed ball bearings. This works well, since this type of sealed bearing typically run for over 100,000 miles in modern car alternators and other applications. But this modification required taking the fan assembly off and shipping it to a machine shop familiar with the modification.
Thankfully there now is a much more convenient way to accomplish this modification and repair.
John Cislak has had a hub made from a solid billet of aluminum, with sealed, permanently lubricated bearings, new shaft, and all the proper holes drilled. This hub assembly makes updating your Pierce’s fan bearings MUCH easier than in the past. There is only normal wrench and screwdriver skills needed for installation, with the exception of needing to remove the no-longer-needed oil slinger. I used a dremel with a small cut-off wheel to remove my oil slinger.
This hub assembly is available for all 6 or 7 versions of the Pierce fan hub, and they are reasonably priced.
I recommend that anyone who drives their Pierce Arrow cars to consider installing either the hub assembly that is mentioned above, or have a machinist modify your hub, or religiously fill your fan hub reservoir.
I do fill my fan hub reservoirs ‘sort-of’ religiously, and did on my cars I took to the Gathering. Yet when we elected to drive one of the cars the 120 miles from the Gilmore back home, I nearly had a similar bearing failure. Checking the car upon arrival at home I noticed that the fan bearing had become very sloppy and there was oil slung all over the front of the engine. and the fan bearing was very loose and sloppy.
So, I’m installing a sealed-bearing hub assembly I purchased from John C last Fall at Hershey. Thankfully I was not stranded on the highway last Sunday.
Greg Long
Well said, Greg, and he’s right, folks….it’s just something that needs lubrication and one never thinks of it….and it seems to be the most common semi-disastrous failure that can happen to our cars…
I believe the previous owner of my ’31 reworked the fan hub, but I’m probably going to go with John Cislak’s fix anyway. His work is excellent, and the price of the new hub, if it saves radiator and/or other damage, is reasonable.
We have one of John Cislak’s fan hubs on our 1601, the installation was fairly simple and we DO NOT miss the oil all over the underside of the hood.
Attached is a Pierce-Arrow Service Department Letter P-609 on fan lubrication reprinted in PAS Service Bulletin 91-1 page 10. After the oil is put in the oil filler hole, the fan can be turned 180 degrees and excess oil will run out and then the screw in the filler hole should be replaced. This is a messy procedure so put some rags under the oil filler hole to avoid getting oil on the fan belts.
Well, attaching the Service Department Letter didn’t work. Go to PAS Service Bulletin 91-1 page ten to read the letter.
I believe in the original design the hub had a standpipe at the drain hole, thus when you rotated 180 degrees as stated, the proper amount of oil would stay in the hub, excess would drain out. The remaining oil is then distributed correctly by centripetal force (engineer speak) to the correct places (I must interject, my family gives me heck about thinking like an engineer, once they were trying to take a picture of our then- 2 year old granddaughter, and I told her “turn ninety degrees” to get her in line with camera…and the response was, seriously, ninety degrees, to a 2 year old??!?…). A good system, well engineered, but it takes maintenance. How many of us are guilty of storing a car for a year or more, then hitting the road on a tour and expecting the car to be 100%. Part of the enjoyment of old cars is tending to their needs, and the more you do so, the more you understand every noise and smell and feel of your car.
For example, my ’31 did a wonderful job of driving 250 or so miles in two days, but the second day I noticed a little water leak down the right side of the radiator shell. I’ve been there before, water pump sucking air, foaming the coolant, most noticeable when you’re driving at speed and back off the gas,causing an overflow, so know what it is since I’ve experienced before. Time to look at packing in water pump, but also water pump grease, as the grease around the water pump shaft performs both lubrication and sealing duty.
As one of the victims of the fan hub failure this past weekend, I fully concur with Greg’s comments on John Cislak’s improved fan bearing assembly. I bought one at the St. Louis meet, but unfortunately did not get around to installing it before the tour. Did it today, and the installation was quick and easy. Too bad I didn’t do it last week. It’s a great product, and beats cleaning the leaked oil from the engine compartment.
Also, many thanks to Dave and Dianna, and the rest of the crew for a most enjoyable event.
Tom Barrett
David is exactly right about the standpipe. The Pierce-Arrow Service Department Letter P-609 recommends using either SAE 40 or SAE 50 motor oil for the fan. Since we tend to drive only in warmer weather SAE 50 is the better choice.
Yeah, and I’m the other guy. The bearing failed about 40 miles into our drive to Kalamazoo and we were on the side of the road on the Tri-State Tollway (I-294) just before the I-80 interchange. I had a spare bearing with me and figured that I could install it and be on my way. Turns out the spare was from a ’29 and does not quite fit a ’31. To make a long story short I was able to exit the tollway and find a gas station and subsequently a machine shop which helped me modify the ’29 bearing to fit well enough to get me back home. It still leaked oil and I knew that I could never try to complete the drive to K-zoo. We got back home at 4:00 pm and chilled out to lower my blood pressure and then drove modern to Kalamazoo and enjoyed the meet.
The cause of the failure is “I forgot to oil it”” Mea culpa.
I’ll be ordering one of John’s bearing assemblies.
Bill”