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My 1926 Series 80 is in process of a complete engine rebuild. The restoration shop tells me that the oil pump shaft, gear, and bushing are badly worn, and the housing is cracked. The timing gears are pretty worn and also should be replaced. Does anyone have any leads for these parts?
The body restoration is done, and completing the engine is all that is keeping us off the road.
Send a email to Greg Long. He is currently the most active series 80 & 81 member. If there is a source he will know it. Ed
Greg is a certified mechanical genius who has healed cars as old as
1910, without the benefit of manuals or prior training. He has been
very generous with his skills and knowledge. A very “cranky” Rambler
has been given a new lease on life due to his generous spirit. When
they open the Pierce-Arrow Hall of Fame, I hope to cast a nomination,
so that he may be honored next to all the others that are deserving.
Tony: you are going to make me blush! I’ll look through my pile and see what I have. I’ve already sent an email to Dr Joe.
Greg Long
Tony,
Allow me to add a ditto to your comments regarding our friend and fellow Society member Greg.
Joe
Joe, did you get photos from your engine guy? I have a pump for you, I have some timing chain sprockets, but they are far from mint. I’d like to see if your’s are worse before I think about shipping them.
Oil pump drive gear on cam? on right angle drive on side of crankcase? Oil pump screen? pump coupler square tube?
I need a photo of the gears also because there were some early engines modified to the later chain. so there might be two different setups.
Greg L
Peter,
Thanks very much for the tip on the oil pump studs. I will send word on to the restoration shop.
Joe
There is a reason that car manufacturers use steel studs threaded into aluminum castings instead of just using a bolt threaded into the aluminum.
The reason is that aluminum is soft, and easily worn, and easily damaged by cross threading when installing a fastener.
The manufacturers put studs in where there would be frequent removal and replacement of the fasteners. The stud is ontended to stay in the aluminum, and any wear, or damage taken by the replaceable stud.
Also, on aluminum, since the metal is soft, the threads are a coarse thread, so each thread has more metal to take the torque and stretch from tightening the fastener. The stud’s exposed threads are fine thread.
Pierce uses fine thread fasteners on virtually every esternal thread, and uses coarse thread when a thread is cut into a casting.
I don’t believe that there were ‘Heli-Coil’ thread replacement products available in the ’20’s, a new casting would be needed if a thread was stripped out, or it would have to be drilled out to the next size fastener and rethreaded.
I’ve changed the oil lots of times in S80’s and s81’s with the studs in the pan for mounting the pump. Pierce recognized that the pump drive shaft and drive coupler was a bit ‘fussy’ to get lined up. So Pierce provided an extension for the oil pump shaft that is round, so it feeds into the drive coupler easily, then the installer with a bit of ‘finesse’ will rotate the pump housing and pump shaft before it’s on the pan studs, and feel the square shaft slide into the coupler, and fit properly.
There is always the annoying distraction of and remaining oil draining out of the pan, over the pump, and down your arm as you are trying to use ‘finnese’ to put the pump back in.
I personally would not replace the normal pierce studs with bolts. If you have damaged studs, then they are hard to find, since they are coarse thread on one end, fine thread on the other, and rather short. I’ve had to make one or two in the past.
Just my take the reason for the studs, and the installation of the oil pump and drive.
Greg Long
I’ll try to remember to take a few photos of a pump and pump drive coupler.
The one and only oil screen or oil filter is on the pump. So I drop the pump and clean the screen and reach inside and wipe the mud from the bottom of the oil pan at least every other oil change.
The pump is not difficult to instal, 6 weeks ago I installed the pump on George’s ’25 coupe, with the bolts, I didn’t find it any easier to do than the pump removal and reinstall on a different ’25 S80 engine two weeks ago.
With studs or with bolts, the difficult part is the same: getting the round guide pin on the pump gear shaft into the square drive coupling. The coupling is not rigid, it flops around on the drive gear, and it’s hard to feel with the pump when the shaft is in the coupling, This is when the pump is 2 inches away from the studs.
The pump / shaft is then slid up inside the square coupling tube. the square of the pump shaft will need to be matched with the square of the coupling. This is with the pump mating and gasket surface 1/2″ below the ends of the studs. So the studs still are not in the way.
Once the pump shaft matches the coupler, then the pump is pushed further up, over the studs.
I really don’t see any problems with the studs. The pump I removed and reinstalled two weeks ago was still draining oil, so it was messy, but it would have been no different with bolts.
I think that the potential for cross-threading a bolt is high, but the studs work just fine..
In the photo below, you can see the guide pin on the pump shaft, and you can also see the 1″ long mark on the square of the pump shaft where the coupler makes contact. the studs are only 1/2″ long, so when the pump is being installed, there is still 1/2″ clearance between the pump gasket surface and the ends of the studs.
If the studs are good, I see no reason to remove them.
I’ll be installing two more pumps on engines I’m working on over the next few weeks.. I guess I’ll have lots of practice.
Greg L
