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nissubaru nissubaru is offline
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Posts: 132
Join Date: Jun 2017
Car: 2009 335i M-Sport
Default Used Replacement Motor on Stand - Should I Do Rod Bearings? - 04-11-2019, 06:04 PM

85k miles on the motor, was just gonna do new gaskets all around including the rear main seal but not the front crank seal. I figure the front crank seal can be done without too much hassle if needed in the future but I'd rather not drop the trans in 20k miles for the rear main if I can do it now.

That's all fine and well, but I gotta ask about doing the rod bearings while I'm in here. King replacement bearings are pretty cheap considering the price of a "new" motor so it seems like a smart move, but is it worth the time, cost and risk associated with it?

For some this might be no problem but personally I've never messed around with the internals of a motor or torquing/angle to spec. It's really not that hard to pull a motor and put another one back in, but I imagine I could really **** things up if I didn't do the bearings correctly.

Part of it also comes down to the torque wrench used and how accurate that is. So I bought a used Precision Instruments M1R200HX off eBay, came with a calibration sheet but I'm gonna test it out on something else before assuming it's accurate. This wrench goes from 30-200 in lbs or 3.5 - 22.5 nM. Rod bolt spec is 20 nM + 70 degrees.

I'd feel better about doing the rod bolts if I had a nice Snap On digital torque wrench to use with the torque and angle settings, but I don't. Other torque wrenches also don't go down to the spec that we need for the valve cover, rod bolts, oil pan bolts etc so that's why I got the one I did.

So, should I just leave it alone or what?
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