1800: Reviving a Saint. 1 UNDERCARRIAGE

[chirlas]

REAR AXLE AND PROPSHAFT
Brushing, cleaning and painting are easy tasks and pay encouraging dividends.

The diff is clearly marked as a 30 model and a metal label (not in the attached picture) states the relation is 41:9 or 4:56. Next step will be checking backlash and crown/pinion teeth patterns, a complete unknown territory for me. VP Autoparts sells an unexpensive marking compound for checking the patterns.

Propshaft is a 44,5mm Hardy Spicer. The UJs seem to have no play, but the central bearing has a little. The plan is to change the three UJs and the central bearing.

About the axles, I have been said that the bearings are rock solid but I tend to think that trusting on them would be a false economy. They are supposedly just 70k km/44k miles old, but I am not able to test their condition. Do you think todays Timken bearings are on par with the period ones?

And a last question: you can see in picture 1057 a plate welded to the propshaft that reads "2/3". What is that?

[grumpydad]

Hi
the plate welded to the prop is for balance
to stop vibration

hope that helps

[Derek UK]

If the mileage is correct I'd not touch the diff or the wheel bearings. Flush the diff and refill. Possibly grease the wheel bearings if you can. Replace the clearance shims as you found them. Centre bearing, change along with the mounting rubber. U/J's, your choice. Make sure the 2 prop pieces are joined back up correctly.

[chirlas]

Derek, I am not able to measure the shims. Both are stuck to spacer washer PN 673789. This part is not available and I am afraid to break it if a try to liberate the shim. Keep it untouched as with the bearings?

[Derek UK]

Shim/shims would probably come off it soaked in penetrant but yes just clean things up and leave them. Spacer 673789 is apparently 4mm thick. 673789 is the gasket. These shims space out the half shaft clearance. There is a thick one on one side that you don't touch and the clearance is then set on the other side via shim thickness selection. These rarely need adjusting except after a major axle overhaul.
Don't try and clamp things up with the oil seat plate bolts if it's all hard to fit. The plate will bend/distort. If you aren't taking the bearings out it all should go together OK.

[chirlas]

I am afraid these are not shims, but spacers. 5mm thick. So the axle has not shims at all. Bearings are 1,7mm proud on right side, 0mm on left. Will I need shims?