[pal]

Last month I had Randy Forbes replace the rod bearings on my Z4MC with his coated ones. My car had 59K miles and close to 50 track days at the time and once the bearings came out, the timing of this job seemed very appropriate. The car has seen very regular oil changes (2-4 track days per change) and all oil has been analyzed by Blackstone that showed occasional high lead numbers.

Below are the pulled bearings. Disregard the sharp scratches as those were from them sitting in a plastic box and hitting each other.

#2 top was the worst for wear, followed by #3 top. #5 had an unsual slant on the right edge indicating that the bearing was possibly mounted at a very slight angle?? Discuss away.






Some of the interesting pictures I took while watching and learning from the master are below.

Positioned for its surgery.


Draining the oil in preparation for removing the oil pan.


After putting an engine support on the front of the motor the Z4MC was raised into position for its surgery.


Steering column removed from the rack and marked just to be on the safe side. Though it looked like it can only go in one way.



Removed subframe bolts - the liquid is just penetrating lube.


Rack unbolted from subframe and subframe removed and out of the way.




Pulleys loosened and power steering pump bracket disconnected


FCABS and sway bar links disconnected and sway bar removed from car. This allows the entire assembly to swing under the car to create a more usable workspace.


Draining the pan.




Dipstick and breather need to be removed from pan. Dipstick also has a nut on the top (near intake plenum) that needs to be removed.


Unbolt the seemingly infinite bolts on the pan and carefully remove it from the block and let it drain on the side.



Cleaned pan ready to go back when its time.


Oil pump and lines removed - the crank is painted blue for some reason.



Now it time to remove one rod bearing at a time (in firing order helps), clean the journals with scotch brite, apply assembly lube to new ones and reinstall.




Fresh coated set


Coated bearing on the right


Plasti guaging the new bearings takes time as they need to be installed and removed and then measured for proper clearance. This works as the new rod bolts call for 5Nm, 30Nm and 105° turn 3 times. So the bolts need to be loosened anyways.




Ready for final assembly after the plasti-guage step. They are not removed anymore.