Jubilee Main Bearings

[Jay in WA]

My Jubilee has very low oil pressure when the engine is warm and not that good when cold (30-35 lbs). I"ve been told the main bearings are probably the cause. How difficult is it to roll out the upper half of the bearing if I decide to tackle this?

 

[ErnieD]

Not a bad job at all. Check the clearance with plasti-gauge and check the oil pump while you are in there.

 

[Fordfarmer]

And probably plan on rod bearings as well as mains.

 

[Anonymous-0]

Am I hearing that the mains can be changed out with the crankshaft in place?

Assuming the crankshaft does not have significant wear damage, can just new caps be installed on the mains & connecting rods, or is that not a wise idea ?

I have a new one that followed me home a few weeks ago, and oil pressure is pretty light.

Pete

 

[Fordfarmer]

By caps, do you mean the bearings? Yes, that is OK, if your crank is OK. The main and rod caps are the pieces you unbolt to replace the bearings... you do NOT want to swap them, as that would mean align boring to attain a proper fit.

 

[Anonymous-0]

Hi Fordfarmer -

Yes, I meant the bearings (shells?) themselves.

Thanks for the feedback. Might be a project I look into in the spring.

Pete

 

[souNdguy]

id' drop a 15$ oil pressure gauge and 20$ oil change into it before i redid any bearings.

bad gauge and gas thinned oil can kill some psi readings....

 

[Jay in WA]

Thanks for all the replies. I've already replaced the gauge and changed the oil. I'm satisfied the low pressure reading is real. When the engine gets up to operating temp it is at about 7-10 lbs. The overall condition of this tractor supports it having been used a lot over the years. Compared to a complete rebuild, changing the rods bearings and mains isn't a big deal. I've just never tried this on a engine so was wondering how big a job it actually is to get the upper half of the mains out and the new ones back in.

 

[showcrop]

Are you aware that you will have to choose between eight different bearing sizes. You should be able to read on the back side of the liner which ones they are.

 

[Jay in WA]

I was planning on replacing with the same size I take out whatever that is. Hadn't given any thought about the number of sizes available.

 

[sunbeam]

A cotter key can be used as a tool for replaceing the upper half of the main bearings. Select a cotter key that the head will fit in the oil hole in the crank then bend the 2 ends so they fit flat against the crank journal. Cut the 2 ends of the key to the width of the bearing. Put the key in the oil hole and turn the crank so the pin comes against the non tang side and you can role the bearing half out.

 

[Jay in WA]

Thanks for that tip about the cotter key. That is exactly the kind of advice I was hoping for. I am extremely thankful for all the practical information that is available here.