Low Oil Pressure on 1945 B

[JDBRIDER]

I have a 1945 John Deere B. I replaced the oil pressure gauge recently because the old one hasn't worked for a couple of years. The gauge I bought is like the original except it doesn't say John Deere on the face. When I run the tractor the gauge reads a little above the Stop point. Doesn't matter what the RPMs are. I don't remember what it showed when the old gauge worked but it was at an acceptable level. I put gas pistons and a cold manifold on it a couple years ago and the connecting rod bearings were within spec then. I haven't checked the main bearing clearances but I did put a dial indicator on the crankshaft on both ends and then lifted up and down on the crank and had 6 thousands of clearance on the flywheel end and 7 thousands on the pully end. I rotated the crank and checked several times on each end. Thinking I should turn up the pressure at the oil pump. Don't know how much to turn it up but thinking a couple of turns. Does that sound like enough. What do you think of my method of checking the mains?
Flame suit on.

 

[Oregon Tractor Jack]

If you really have that much play on the main bearings, its no wonder you don't show any oil pressure. Main bearing max running clearance is 0.003. End play is max at 0.007 that's the thrust bearing in and out clearance. You can pull the center main cap and use some plastigage to measure the main bearing clearance.

OTJ

 

[MSD]

Might try a better grade of gauge. Evergreen Restorations is the best place to get them. His are accurate.

 

[Paul from MI]

Hate to tell you this, but a B has no center main bearing. While the clearance is excessive it is most likely not the problem. Suspect what you changed, check with a known good master gage. Should be 10-15 psi.

 

[Oregon Tractor Jack]

My bad, need to read better. Its a JD not a Farmall, not quite the same animal...


OTJ

 

[rustred]

your first step is to screw in a master gauge , one reading in lbs. then you know where to start. un- till then its guessing game. pretty sure it wont be a couple turns either. then u watch the gauge while turning up the psi. pretty sure your crank spec's are maxed out also.

 

[ztw2009]

I agree with MSD and recommend a gauge from Evergreen Restoration. Jerry is great to deal with and his gauges are top of the line. It may be as simple as put one of his gauges on and it may read right where it needs to be. I bought crap gauges on eBay 1st that looked great but were worthless. I have bought gauges from Evergreen since and will continue to do so.

 

[Muir hill 101]

Make sure you dont have sludge

 

[ss55]

OP wrote:
Thinking I should turn up the pressure at the oil pump. Don't know how much to turn it up but thinking a couple of turns. Does that sound like enough.

If the crankcase oil pump is not moving enough volume to build up any pressure, then adjusting the pressure relief setting will not have any effect.

In this case buying an inexpensive I&T shop manual for your tractor could have some great information until you decide if you want to get the more expensive factory service manual. They are sold on this Yesterdays Tractors Co website and other places. https://www.yesterdaystractors.com/JD4_9188.htm

 

[JDBRIDER]

I ordered a gauge that reads in PSI 0-15. I'll see what that says and go from there.

 

[rrlund]

I'll agree with the guys who are saying get one from Evergreen. They're calibrated. A lot of the ones offered by other vendors aren't any good for anything but decoration. You should have checked the pressure with a good calibrated test gauge before you threw more money down a rat hole.

 

[rustred]

the thing is on gauges... u want your maximum reading 3/4 the way up. so if your setting the psi to 15 then you should be using a 20 lb gauge.

 

[Koolaid]

Echo the rest - check with a known good and accurate gauge before doing anything else.