spun rod bearing.....again

[7m_no_sht]

Hey guys about a month ago I spun my no. 1 rod bearing. I took the 7m out riped it apart and sent the block off to get ground down because it was beyond just cleaning it. Put another rod in from the other 7ms I have and got the head and block decked and tanked. Ordered .020 oversized rod bearings and .010 main bearings along with a full rebuild kit. I just finished putting everything back together and dropped the engine in did the 20min break in changed the oil and went out to begin the 250mi break in process, about 15 miles in it spun another bearing. I have no idea why, I checked the gaps and the torque on everything 2 or 3 times and everything was to spec. Anybody have ideas why it spun again and what I can do to prevent it from happening again

 

[DEFIANT 7M]

Have your rods resized next time. Also what brand of bearing are you using.

 

[AJ'S 88NA]

They usally only "spin" if it runs out of oil, too tight of clearance, hard braking and cornering, etc.

 

[mecevans]

Did you pull all the oil galley plugs our and clean it?

 

[7m_no_sht]

i didnt need the rods to be reground, theyre king bearings and i checked the gaps with plasitk gauge all was in spec

 

[MPR]

If everything was to spec, then I would lean towards an oiling problem...

 

[SRZMK3]

oil pump issue which was prolly the first reason, next time clean out the oil passages and get a new pump in there.

 

[IJ.]

20 under "might" be under the hardness of the stock Toyota Induction hardening, cold/dry starts the crank is soft enough to pick up some bearing material, do this a couple of times and you get enough material transfer/galling to flatten a tang and the bearing is toast.

When you pull it down take some good macro pics of both the bearing and the crank pin and post them here.

Ditto on pull ALL the crank plugs and clean the crap out, you can never be too clean when assembling an engine.

 

[7m_no_sht]

Used plenty of assembily lube rebuilt oil pump and added shimms so it wasn't the pump

 

[7m_no_sht]

20 under "might" be under the hardness of the stock Toyota Induction hardening, cold/dry starts the crank is soft enough to pick up some bearing material, do this a couple of times and you get enough material transfer/galling to flatten a tang and the bearing is toast.

When you pull it down take some good macro pics of both the bearing and the crank pin and post them here.

Ditto on pull ALL the crank plugs and clean the crap out, you can never be too clean when assembling an engine.

What are you talking about 20 under? I said I had oversized bearings not softer ones

 

[IJ.]

Crank is UNDERSIZE

Bearings are OVERSIZE to make up for what's been removed from the Crank...