Pan is off Z134 Gas engine on Massey f40, now what?

[Gale Hawkins]

Did you have it polished because it looked like it needed or just to make sure you were rebuilding with a known good used crank?

 

[Texwing]

Did you have it polished because it looked like it needed or just to make sure you were rebuilding with a known good used crank?

No, this is a running tractor that runs well but had low oil pressure, so I pulled the pan to rebuild oil pump and figured I would change the rod bearings, and in fact they are all worn but evenly. I think it appears to be a good mid life engine. The crank is not scored but has some discolorations and wear patterns typically around the oil hole. I have no time for a rebuild till next winter, and this will be a very lightly used machine. If oil pressure is not restored I will park it till next winter. By the way, changing the rod bearings "engine in place" is tougher than I thought, but just because your on your back and stuff is falling in your face, and you cant rotate the crank fully around due to dangling rods, and so forth. But still doable so far.

 

[The kid]

No, this is a running tractor that runs well but had low oil pressure, so I pulled the pan to rebuild oil pump and figured I would change the rod bearings, and in fact they are all worn but evenly. I think it appears to be a good mid life engine. The crank is not scored but has some discolorations and wear patterns typically around the oil hole. I have no time for a rebuild till next winter, and this will be a very lightly used machine. If oil pressure is not restored I will park it till next winter. By the way, changing the rod bearings "engine in place" is tougher than I thought, but just because your on your back and stuff is falling in your face, and you cant rotate the crank fully around due to dangling rods, and so forth. But still doable so far.

If you replace each rod bearings one at a time, you can rotate the crank. My two cents. -kid

 

[Texwing]

If you replace each rod bearings one at a time, you can rotate the crank. My two cents. -kid

You are correct on that but I was following another piece of advice to get all the rod bearings off, to go ahead and find any unhappy surprises-happily no surprises.
I plan on getting the new rod bearings in, barely tighten the bolts, then rotate the crank as needed tighten.

I have not figured out how I am supposed to rebend the lock tabs downward on the rod bolts when all back together-and thought appreciated.

 

[Gale Hawkins]

Are not worn mains more of a low pressure cause than rod bearings? When I was a kid we bought an 841 that off the truck it would show a drop in oil pressure if on a steep incline. The dealer came and picked it up and said he was going to put new mains in it. All I know was it came back without the same low pressure issue on a steep incline.

Sounds like it may have been ran with dirt oil due to the wear pattern but metal will naturally wash due to the oil flow path a bit.

With my limited experience over the years I have never seen low oil pressure that was oil pump related but they were all gear based pumps.

 

[Texwing]

Are not worn mains more of a low pressure cause than rod bearings?
Sounds like it may have been ran with dirt oil due to the wear pattern but metal will naturally wash due to the oil flow path a bit.
With my limited experience over the years I have never seen low oil pressure that was oil pump related but they were all gear based pumps.

Hi Gale thanks for the reply, I have never had a bad oil pump either. and the rod bearings are the only thing I can change easily; If i dont get acceptable oil pressure back I will park it, If I do then it will be low hour light duty use only. I have blown up 3 old muscle car engines in my time (long long ago) and it was the rod bearings that always spun, so I hope between pump and rod bearings it will come back enough to have an easy working life. We shall see.

 

[Gale Hawkins]

Hi Gale thanks for the reply, I have never had a bad oil pump either. and the rod bearings are the only thing I can change easily; If i dont get acceptable oil pressure back I will park it, If I do then it will be low hour light duty use only. I have blown up 3 old muscle car engines in my time (long long ago) and it was the rod bearings that always spun, so I hope between pump and rod bearings it will come back enough to have an easy working life. We shall see.

Actually your plan sounds good and you might just get as much life as you need out of it with your simple plan of attack.

 

[Texwing]

Actually your plan sounds good and you might just get as much life as you need out of it with your simple plan of attack.

Well I hope thats right, if anything else I could do (easily) to restore oil pressure i would. I did order the spin on oil filter adapter for now to not have any questions on filtration on cleaning up what remains of the old oil. as far as I can tell from looking at pictures online of rod bearing wear and failures, dirt and debri in oil was the a factor here (and it still runs great). The spring inside the canister filter was messed up, no washer, I suspect no filtration had been taking place for a while. I came home with a 46 Willys jeep still running, and the old canister filter was removed and bypassed, dont know what folks are thinking on that one.
Anyway, i will go to synthetic oil and its been by experience on old half worn engines that further wear can be really slowed to a crawl if you get to them in time. hope this is one of them.

 

[Gale Hawkins]

Well I hope thats right, if anything else I could do (easily) to restore oil pressure i would. I did order the spin on oil filter adapter for now to not have any questions on filtration on cleaning up what remains of the old oil. as far as I can tell from looking at pictures online of rod bearing wear and failures, dirt and debri in oil was the a factor here (and it still runs great). The spring inside the canister filter was messed up, no washer, I suspect no filtration had been taking place for a while. I came home with a 46 Willys jeep still running, and the old canister filter was removed and bypassed, dont know what folks are thinking on that one.
Anyway, i will go to synthetic oil and its been by experience on old half worn engines that further wear can be really slowed to a crawl if you get to them in time. hope this is one of them.

I have been impressed with the Mobil 1 High Mileage put in the 2003 5.3L engine. It is looking dirty after 1500 miles and may change it before the 3000 mile requirement by Mobil. It is super at cleaning and had one of the best anti wear packages that I have read about for older engines.

It would be my guess the 46 Willys did not have a filter when new. We got a 1960 Chevy straight six in 1965 with only a couple thousand miles on it and it did not have an oil filter. Dad got a nice add-on canister type Fram kit. I think it attached with U bolts to the intake manifold perhaps. I guess it came with a T fitting to go where the sending unit screwed into the block.

 

[Texwing]

HI Gale, actually the 46 Willy's did have a remote canister filter (I have two others) that oddly did not filter all the oil in one pass, but it still better than nothing. Not sure why anyone would remove it. I am struck that the Mobil 1 high mileage is asking for a change at 3000 miles, is that correct? Must be from the blow-bye of an older engine perhaps? I have so many cars and old engines that I just run Mobil 1 10-30 weight in everything from Kubota Diesels to power washers to cars. Would not claim (and thus start a forum war on oil ) its the best plan but its worked for me, and I have never lost an engine on it, even old worn out stuff. So, if the tractor oil pressure will come back, I am pretty sure it will keep going for a while.