I disassembled my rear axle to inspect it and do a rebuild as necessary. I found one bronze thrust washer to be severely worn as compared to the other one. The worn one measured .110 thickness and the other one .172 thickness. Does any one have an idea what would cause this?
The only other component that showed severe wear was the spider trunions and the spider gear bushings which measured .025 to .031 inches clearance. The spec is .005. I know I will have to replace these.
Other than some medium spalding on the ring and pinion gears I have found no other issues.
By the way the axle worked just fine in the car but I was not
sure if it had bronze thrust washers or babbit.
I will try to attach a picture. Thanks, Joe
I will attempt to attach a picture
I may have been ground done to set the side clearance in the rear end.
The thickness of thrust washer was probably reduced to adjust the position of the differential in the housings. This would be done after the ring gear/pinion gap is set. All this is described in the Rear Axle Rebuild booklet. I am going down the same road as you right now for the same reason.
Well yes, I guess the washer could have purposely been ground away to accomplish proper adjustment but I didn't mention that the oil was extremely contaminated with bronze wear particles so I just assumed it must be wear.
Maybe I should reassemble the axle and take a closer look at the lash--maybe that will tell me something.
Could the worn out spider and gears have any bearing on the washer wear?
Any other thoughts? Thanks Joe
What is the condition (surface finish) of the steel thrust washers that sandwich the bronze thrust washer in place, and are the pins that keep the steel washers from spinning still in good shape?
If one of the thrust washers was severely worn you would have lots of side clearance on the differential. That clearance should be as near to zero as you can get when you put it together again.
I agree with all the above with exception. If the wear was on the left side of the axle, it could have been caused by the thrust of the ring gear which tends toward the left side of the car. Measure the clearance of the gears. What Royce says would apply to new gears, but sometimes the wear pattern of used gears would indicate a larger clearance. If worn gears are set too closely, you will get a very rough mesh and howling of the gears. When you set up the clearance, and everything is assembled try turning the driveshaft. It should turn very smoothly. If it binds and feels tight or jumpy, the gears are too tight.
The side play of the differential to the axle housings is not used to set clearance on the gear set. Side play should always be as near to zero as possible on a freshly assembled unit.
The relative position of the differential and the depth of the pinion is used for setting gear mesh and clearance.
Thanks for input from all. I will post what I find when I reassemble the parts and note side play looseness. Also I will determine which side,left or right the wear was. Also I will look at the gear mesh pattern and location. It will be into next week before I get back at it due to other things that I must do. Joe
normally the fiber button between the axles is too thin to get you to zero clearance like royce said. i have always made one thicker from brass, so there would likely never be any reason to machine the thrust washer thinner.you have other issues for sure
Me too, I use a brass washer instead of the fiber piece.
I agree with Chris...
On axel halves that have been abused in the past, and/or the babbit thrusts breaking/disintegrating , the holding pins could have been ground down, forcing the steel washer to grind against the flange on the inner axel half... especially on the driver's side. Since the new thrust washers are made a bit thicker, it is logical to find unequal thickness thrusts to center the carrier.
These rear ends were designed with no adjustments. The .200 bronze thrust washers were installed with the steel thrust washers on each side. All the early parts books I have show this part as bronze, however there are babbit assemblies as well but I don't know when they were used. The assemblies were not that closely fitted originally. I don't know why your bronze thrust washers wore so severley, but it is usually related to lubrication or the lack thereof. The differential was designed for grease not heavy but creamey, if oil was installed it may have leaked out and caused excessive friction, refilled with the grindings in there and you have a perpetual abrasive solution. Also it is possible that engine oil can migrate down the drive shaft and enter in to the housing and mix with the gear oil. Ford differentials were designed for grease, early reference manuals require #2 grease, however it is a bit thick, #1.5 is slightly lighter and creameyer. If you pick the grease up with a fork it shouldn't flow through, it should be like whipped cream. NGLI viscosity standards 00, 0, 1, 1.5 would be preferred. Some of these greases are available through Restoration Supply in CA.
Just an update on my findings after cleaning all the parts and looking at things a little closer.
The worn bronze thrust washer was on the left side and it's steel washer was grooved up with marks where it had ridden over the pin and worn the pin nearly flush with the housing. I suspect the steel washer may have been resting up on that short pin when it was reassembled as there are witness marks where it stopped at different locations and ran that way which would cock the washer and put heavy loading on the bronze washer and resulting wear.
I now have it all rebuilt with new ring and pinion gears, all new pins, new bronze and steel washers and new axle shafts.
Zero axle end play, .006 gear lash, gears centered well and everything turns nice and smoothly. Also replaced the spider and gears so the rebuild turned out well and should be good for another 100 years. Once again thanks for the help. Joe
Well it sounds like you have got it right now, that is a lot of new parts should be good for ever .006 clearance is just right. I did a job like this on my 15 and I was so proud of my achievements bolted everything up with no binding it was perfect only to find I had the internal assembly on the opposite side and the whole thing was running backwards but it was smooth. I just had to find a way to run the engine the other way. Looking through some early accessories there was available ball and roller bearings available in place of the bronze thrust units I don't know how they stood up but they looked good. Continued good luck with your project.