B6100 Overhaul Problems

[Peacefield-Farms]

Here is one for Vic and the wrenchers. I have a B6100E, the tractor had low oil pressure after it gets hot (the oil light came on if less than about mid throttle). I suspect the tractor has been in a flood so I thought no big deal I will just replace the bottom end (top end is good no oil usage and good compression). After taking the engine apart the bearings look ok they plastigauge out to about .002 to .003 (.051mm to .070 mm) I also found what looks like the remains of an aluminum plug (like the ones in the crank in the oil pan). My question is would the bearings being still with in spec (per wsm manual .0012 to .0035) cause the low pressure and also is there any place the aluminum plugs are used other than the crankshaft.

Any advise would be great help, I don't want to put the tractor back together until I can figure this out.

Some pics of the tractor http://www.flickr.com/photos/theevillones/

Also do I need to replace the rod, head, bearing holder bolts or can they be reused?

Thanks

 

[aquaforce]

Check the front cover and /or front of the block. THere are some oil passage plugs used on some engines that could have blown out.


The holding/retaining bolts are just like head and rod bolts. Unless there is damage they are fine to re-use.

 

[bruceatlam]

You may want to also check the oil pump itself as well as the oil pressure relief valve spring -- that relief valve may not be holding to a high enough pressure and the oil pump may be so worn that it's not pumping sufficient pressure.

I'm also a little leary of plastigauge. If you simply mic the journals, do they measure to the spec? If the journals mic to spec and you use new bearings, you should, by definition, have the correct clearances.

 

[traildust]

Just maybe, you need a new oil pump. As you increase throttle the pump is not capable of keeping up with the demand.

 

[bruceatlam]

Do you have any idea what the oil pressure was when the "light came on" --- do you know that it was really "low". I think that the light is designed to come on at 7 psi -- do you know that you actually were at 7 psi or lower?

 

[JWB]

Its not uncommon for the pressure senders to go bad. Double check with a manual gauge to be sure.
JWB

 

[handyman]

I agree with JWB and all the other post .I would definately check all of the above suggestions before I started tearing everything down and spending a lot of money that may or may not be necessary.handy

 

[ipz2222]

Aluminum plugs in the crankshaft???? What are you referring to??