Rod Bearings

[pickerandsinger]

My Rod bearings are .010...The plasti gauge reads .005...Book says .002-003...What size bearings should I use.....002,010, or .020....Changing from the under the tractor,...No crankshaft work needed...Thanks my math aint that good...

[ntrenn]

020 will give you interference...010 May snug them enough to get into 003 range. STD are completely out of the question.

[Glen]

Hi,
If your crankshaft has been turned down to .010 undersize, and you are not removing the crankshaft from the engine, all you can do is put in new .010 undersize bearings, and then measure with Plastigauge and see if the clearance is better.
You didn't say if the bearings look old and worn, or still in ok condition.
The journals should be measured to see if they are round, they can get flat places on them, from wear over time, maybe you knew already.

The .002 undersize bearings are only .002 smaller than standard bearings.

[jsfarmall]

Hi,
If your crankshaft has been turned down to .010 undersize, and you are not removing the crankshaft from the engine, all you can do is put in new .010 undersize bearings, and then measure with Plastigauge and see if the clearance is better.
You didn't say if the bearings look old and worn, or still in ok condition.
The journals should be measured to see if they are round, they can get flat places on them, from wear over time, maybe you knew already.

The .002 undersize bearings are only .002 smaller than standard bearings.

He's exactly right. Your only option is .010 bearing. Chances are they are wore enough to get out of tolerance.

[TallCoolOne58]

With your circumstances, .010" under rod bearings are realistically your only option, since obviously your rod journals have been turned, and you're unwilling to remove and have it machined further. Measure journals carefully, definitely use plastigage to check each bearing clearance as you replace. Check for proper crankshaft rotation after final torque of EACH bearing as you go along, to let you know a problem bearing quickly. Cross your fingers, and hope for the best. .005" is a bit excessive, in the hopes of obtaining .002-.003" clearance with a new set. Good luck and hope it works out for you.

[pickerandsinger]

Thanks to all who responded...The replies are kinda like what I was thinking but I was hoping I was wrong and it could be corrected by a thicker bearing...The tractor has a loader on it and I was hoping to rectify the knock I acquired without pulling all that off...I'll throw a new set of .010 in and see what happens...Again thanks..I'll post what happens..Dave