John Deere 1070 Low oil pressure light

[super55]

I agree with the pressure drop at idle once the engine warms up is typically from worn main/rod bearings. Sounds like there is too much clearance and not enough resistance and causing the pressure drop. Did you ever get a breakdown of bill on parts and labor? If so somewhere on there should have been a price for bearings.

I use Lucas oil on an old Avery tractor to help pop up the oil pressure and it actually works pretty darn good. The motor in it smokes from worn rings and has hardly any oil pressure but what is one to do when Hercules motors went out of business in 1956. Figured I would just keep running it until she dies.

 

[TimberHole]

Considering that this tractor ate a crankshaft I can’t help but wonder if a loss of oil pressure was root cause of that failure. If he reused the old pump I would check that. As asked by Super55 does he have a receipt for new main bearings? Rod bearings? Was the crank you bought ready to install or did you send it to the machine shop? Did anyone turn it or measure it? He ought to know off the top of his head whether the mains and rods are standard or whether they were undersized.

 

[dodge man]

They make something called plasti-gauge where you can check bearing clearance. You pop off a cap, slip the plasti gauge in, torque the cap down and it squishes out. Take it back apart and you compare it to a chart and it shows the clearance. I’d do it on one main bearing and one rod bearing. The advantage is you can do it in the tractor if you can get the pan off.

What happens is if the clearances are to great all the oil squirts out down low in the engine and doesn’t make it to the top end.

If it’s not the oil pump it sounds like a sloppy rebuild to me. New bearings don’t do any good if he should have used undersize ones to start with.

 

[scratchpad]

Considering that this tractor ate a crankshaft I can’t help but wonder if a loss of oil pressure was root cause of that failure. If he reused the old pump I would check that. As asked by Super55 does he have a receipt for new main bearings? Rod bearings? Was the crank you bought ready to install or did you send it to the machine shop? Did anyone turn it or measure it? He ought to know off the top of his head whether the mains and rods are standard or whether they were undersized.

Possible ,however, i would have noticed the low oil pressure light if so. Could have been a known issue and thats why the neighbor sold it. Anyhow, No receipt for parts breakdown of bearings. I have a receipt for parts = $ and labor = $. I sourced the block and crank (hot tanked and magnaflux) which were sent to the machine shop prior to me taking them. The crank was round, polished, free of cracks and within spec. I called the machine shop. Im pushing him on the bearings and or oil pump. Shouldve done it right the first time.

 

[scratchpad]

They make something called plasti-gauge where you can check bearing clearance. You pop off a cap, slip the plasti gauge in, torque the cap down and it squishes out. Take it back apart and you compare it to a chart and it shows the clearance. I’d do it on one main bearing and one rod bearing. The advantage is you can do it in the tractor if you can get the pan off.

What happens is if the clearances are to great all the oil squirts out down low in the engine and doesn’t make it to the top end.

If it’s not the oil pump it sounds like a sloppy rebuild to me. New bearings don’t do any good if he should have used undersize ones to start with.

I was gonna plasti gauge it myself and then he agreed to come pick it back up, for the third time.

 

[Old Guy in Tenn]

Diesel fuel does not lubricate as well as oil. Could be that running it with fuel in the oil has damaged bearings, such that now it is losing pressure due to excessive clearance. Seems it had a LOT of fuel in there before the fuel pump was replaced.