Disassembling Heads

Disassembling XV heads is a fair amount of work, especially high-mileage units or machines that have just sat for a long time. The valve covers and cam-end caps are relatively easy; as is freeing and pulling the cam -- provided it is in the TDC position. It may be a bit problematic to break loose the sprocket-fixing bolt, but anyone with any brains pulled the cam sprocket to drop the cam chain.

The rocker shafts can be another story. Back in the day, I would thread in the 8mm allens that had held down the head and give a pull with some vice grips. Sadly, those days are gone. Now-a-days, one must improvise a tool to pull them. Apparently long use and long disuse have tightened them for different reasons. Hot and cold cycles have slightly warped the heads so that the shaft bores are no longer straight. Long disuse has bonded the material of the shafts to the aluminum of the head. Now, I take a long (> 80mm) bolt threaded up to its head with a nut run up it and a large flat washer. I run in the bolt until it no longer turns, then run the nut down against the washer flat against the head. This draws the shaft out -- sometimes enough to pull the rest of the way. Usually, the bolt must be turned out and a spacer (a 17mm or larger deep socket works) must abut the head. The bolt is run in again, the nut run down, and this is usually enough to pull the shaft clean out. Pull, then grasp the shaft with vice grips (it is very hard, you will not hurt it), and turn out the bolt.

If the cam port is facing down, the rockers usually just drop out. You may need to pull and turn them otherwise. Stainless fittings are not hard enough to pull the shafts -- you may get two of them out before the nut refuses to budge.

More to come . . .

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