Rebuild or not ???

I started working on the 640 ford while it is cold. I pulled it into the barn and was going to replace the inner seals in the rear end to stop the gear oil leak and replace the PTO seal.






Since it was cold and the front of the tractor was closer to the wood stove I packed the front wheel bearings. Of course the spindles were a little sloppy so I rebuilt the spindles. The bushings did not look bad but the new ones took the slop out.








Well as I get to poking around it appears the front axle pin and bushing are in need of attention. Off comes the sheet metal and the rear fenders. I need to patch some holes in one fender any way and the lift needs fixed and think it would be easier to reach with the fender off.



While hammering on the axle pin the radiator starts seeping. I am tired of the rotten radiator so I ordered a new one. Should be here soon.

Got the pin and bushing out. Looks like I got the best out of the bushing.





I now need to add that to my YT parts list that includes seals, gaskets, clutch, pressure plate, tune up kit, proof meter and a bunch of other stuff.


While looking around the engine I noticed that every gasket looks to be seeping some. I had planned on ordering a complete gasket kit. Maybe I can paint it after I get the oil leaks down to a minimum.




[b:2e9ba37492]Then I get to thinking…Should I freshen up the old motor with a new set of rings and lap and adjust the valves? I only need to unbolt the engine and I have to inspect the clutch before ordering one. It doesn’t smoke, does not leak much out the rear main (quarter size spot after a hard work out), has some blow-by, and only uses 1 1/2 quarts of oil in 100 hours. It holds 40 psi oil pressure with 15W-40 no matter how hot or how hard I work it. It is 65 years old and I could mess something up. It is not my main tractor as I have the new MX5200 Kubota. So then I wonder if I would be better off leaving the engine alone till it needs something major?[/b:2e9ba37492]

you have already put a lot of money into it, and plan to keep it for some time and finish the work you have started, I think I would do the rings and valves, The bottom end is likely into specs. Use plasti-gage and check bearing clearances. Look closely at the oil pump drive hex shaft. It is on the bottom of the distributor. Replace if it shows wear on the hex corners. That is the weak spot of that engine. While replacing rear seals, how are the brakes?

No more than it would cost you I would think you would be better off replacing the rings and seals. whole lot more of a problem getting it all broke down and you are 95 percent there now. relative inexpensive if you can do it yourself and it appears you can good luck either way.

(quoted from post at 19:00:38 01/27/19) While replacing rear seals, how are the brakes?

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Don't know about the brakes shoes. I guess they are getting thin. I will replace them when I get to rear end if they need new shoes.