Unmatched Rocker Covers - possible?
Posted: Fri Apr 17, 2026 11:46 am
Hi all,
My rocker cover has a chunk broken off where the oil feed bolts on. I believe a brake banjo bolt was used to attach the oil feed to the top of the rocker cover (XTZ660 3YF / 4MY), which is too long. It caused a crack, oil leak, and then finally a chunk of aluminium broke off. 1 inch x 1.5 inch
I have two options and would appreciate advice on whether either is possible:
1) Go to a good welder to get it repaired. I'm worried about it warping causing problems for the cam journal or sealing between the head and rocker cover. (Do I need to remove rockers for this? It seems like a pita)
2) Use a second hand rocker cover. The cam journal is half in the rocker cover, half in the head and I believe that they are bolted up and line bored as a pair. My fear is that oil clearances between cam shaft and journal are about 0.02mm, and that dowels are are machined at best to 0.05mm tolerances (a guess). I could end up with a step, poor oiling, and ruin the cam shaft.
Many thanks in advance.
My rocker cover has a chunk broken off where the oil feed bolts on. I believe a brake banjo bolt was used to attach the oil feed to the top of the rocker cover (XTZ660 3YF / 4MY), which is too long. It caused a crack, oil leak, and then finally a chunk of aluminium broke off. 1 inch x 1.5 inch
I have two options and would appreciate advice on whether either is possible:
1) Go to a good welder to get it repaired. I'm worried about it warping causing problems for the cam journal or sealing between the head and rocker cover. (Do I need to remove rockers for this? It seems like a pita)
2) Use a second hand rocker cover. The cam journal is half in the rocker cover, half in the head and I believe that they are bolted up and line bored as a pair. My fear is that oil clearances between cam shaft and journal are about 0.02mm, and that dowels are are machined at best to 0.05mm tolerances (a guess). I could end up with a step, poor oiling, and ruin the cam shaft.
Many thanks in advance.