#6 bearing (connecting rod)

[w8me1st]

is it just me or is it common for that bearing to be the cause of rod knock? i was just wondering cause i remember reading in a toyota forum that upon his disassembly, number 6 bearing was also why his engine began knocking. if it is common, just needed to know any precautions before assembly so it doesn't happen anytime soon. i have an 87 w/ 130k miles. wasn't low on oil, pressure read normal as usuals (thru out rpm), and had been 2 days since i chaged the oil. then after i had a little fun w/ an srt4, heard a new noise (barely noticeable) at the next light. srt4 driver wanted to go again cause he shifted late out of 2nd, thats why i got ahead of him. luckily for me a cop pulled up before light was green and home i went. but tomorrow everything will be put back together and wanted to know if theres anything i need to know while i have everything out.

any input is greatly apppriciated. thanks

 

[gixxer750]

that bearing is the furtherest from the oil supply. I guess it would get starved for oil first....

 

[GrimJack]

Both my cases of rod knock have been other bearings... #3 on one engine, #4 on another.

 

[w8me1st]

thanks gixxer and grim jack. was just curious. but it sounds like any bearing is possible. and 6 being the furthest makes sense too. is there anything i need to know other than making sure everything stays clean clean clean?

 

[IJ.]

Make sure the pan is full full full !

99 times out of 100 RK is from low oil.

 

[GrimJack]

I'd seriously suggest pulling the plugs on the crank so that you can clean out the galleys in there. Otherwise, your problem might have been caused by a plugged galley and the new bearings will only last minutes at most.

 

[w8me1st]

doing that tonight grimjack, thanks for the info/help everyone

 

[figgie]

Both my cases of rod knock have been other bearings... #3 on one engine, #4 on another.

Ditto mine failed on #2.

I think it is just a myth that #6 fails the most often.

 

[GreenChevelleSS]

Well when I pulled my engine apart all the bearings were worn bad but #6 was the worst i mean about 3 times worse than the other bearings...

 

[Loki]

I've taken apart two 7M's with spun bearings, both #6.

 

[miggles]

orignal motor - spun bearing #1 + rod knock. Not sure what cyl's though.
2nd motor - rod knock #6.Copper colored bearings where as the rest are still grey/silver.

Ive seen on some cranks (not sure of the engine)the oil holes have been modified by putting a slight Vee shaped slit running before and after the oil hole in the crank.
eg | ==O== <!-- Vee shaped slit
Anyone heard of this or done it?

 

[bluepearl]

On a used motor I bought, #1 and #6 were factory perfect. 2,3,4,5 were worn. IJ told me it was caused by detonation. IJ was right, as verified by other experienced engine builders. New #2 bearings brought everything back to snuff. I got a good spare motor.