H&H Model A motor thrust bearing issue

[edgar44]

I've just repaired the thrust bearing on the center main of my H&H touring motor purchased in 1999. I didn't own the car at the time (1928 Model A Tudor) but the fellow before me put on a lot of miles of cross country touring. (Over 30,000+) and I've put on another eight to ten myself.

A bad knock showed up last year and I found that the crankshaft slid forward and backwards quite badly. Last Fall, I spoke with someone from H&H of La Crescenta, CA who told me the fix was simple. Basically remove the oil pan, drop the center main and send it to H&H with dimensions and they would replace the thrust bearings.

It must be stated that H&H uses a unique design in rebuilding Model A motors with replacing the rear thrust bearing with thrust bearings placed fore and aft of the center main bearing. They are pinned in place using roll pins.

A simple process which I undertook myself these past few days after some coaching over the phone by Max Sr. The parts were sent out quickly and gratis! Here are some pointers I'd like to give for those attempting to do this themselves:

After dropping the oil pan and center main; the major and minor diameters must be measured. This is needed by the folks at H&H to ensure proper fit of new thrust washer bearing.

Once the new bearing washer is received, remove the old and sand smooth the surface in preparation for the new application. (The roll pins are too hard to drill out)

Using a Bridgeport type mill, I placed the center main bearing in a table vise and using a 1/8" drill, drill ONE pin hole. Then clamp the bronze thrust washer on to the bearing side and drill through the washer in precisely the same place. After the hole is drilled, drive the roll pin in place and then locate the drill bit over the next location a hole is to be placed. Swing the bronze thrust washer out of the way and drill another hole for a second roll pin into the side of center main. Once drilled (3/8" deep) swing the bronze thrust washer back in place and drill a hole through it as well. Pin and your set.

Remove from vise and grind away excess roll pin that protrudes above the surface of the bronze washer. Be sure to grind off the roll pin below the surface of the thrust washer as it is hard and you don't want it grinding in to the side of the crank shaft surfaces. Repeat the same process on the opposite side of the center main and then your ready to install.

A tip on reinstalling: Be sure that the surface on the crank shaft where the thrust washer is riding is smooth and free of blemishes which will cause premature wear. If necessary, you might need to polish this area. You may also need to sand a bit off the bronze thrust washers if they are too tight going in. Do this carefully on an upright surface sander being sure to keep straight while doing so. There should be no more than .005" play in the thrust washer, fore and aft.

H&H Antique Motors have taken some criticism over this design from some folks but I find it a quality design although it must be addressed every so often... In my case, after more than 40,000 miles!

I'm not sure why I waited so long. This process took less than 6 hours...I didn't really need to wait so long! Over a year!


Have A Great Day!