Procedure for removing head cover

2004 (3 chain) - I am confused reading through the workshop manual and other manuals that I have for what hold down tool to use to remove the cover. Workshop manual says to use tool 9643 and to have slot on the intake cam should be pointing out toward the cover. When in TDC 1 for bank 1 on a 3 chain, the slots in the intake cam are horizontal with the head cover (with the smaller half moon pointing towards the head cover) as pictured below. In this position, the cam alignment tool will fit into the groves of the intake and exhaust camshaft, also pictured. Does the bolts set at 15 mm for intake and 17 mm for the exhaust just set into the circle end of the cam shaft ends so that the bolt heads hold down the camshafts? Wouldn't fixing the alignment tool picture with a bolt serve the same purpose? The manual says it is important to hold down the camshafts prior to removing the cover but none of my manuals show any detail for how the tool 9643 is attached for removal. As context, I am tearing down the engine for rebuild.

Hi Dan, Do you mean 9634? This one below? With the bolts in the holes you can remove the valve cover with the cam held down on both ends. Then you can work on removing the stuff on the chain/sprocket end of the cams with out too much strain on the cams.

That's the tool I mean Gary. Just don't understand how that tool is applied and why the cam alignment tool wouldn't do the same thing? And then second, why the manual says the slot on the end of the camshaft should be pointing towards the cam cover? For disassembly, I can't really think of why it would matter where the orientation of the crank/piston/cams were for taking it apart.

I think it allows for some degree of movement, rotation while holding the camshafts at that end and allows the cams to pivot a bit as you back off the bolts on the front bearing caps, hopefully not breaking the cams (like the lamp we saw in class). If you want to borrow one of my 9634 (and promise to send it back email me and I'll send it you you in the morning. I would think the cam locking tool would put too much restriction on movement during disassembly I have a picture of our teardown motor and it wasn't at TDC when we took it apart so I don't think it matters much. Its probably good practice though.(?) But if you have a broken engine, that aint gonna happen.

thanks Gary. I have the tool, just don't know how to use it. Reading through the Bentley manual for the 3.6, it doesn't say to do anything to hold down the cam ends or fix the crank position. It just says to remove the cover bolts once all the various solenoids, etc. are removed. I find the routing of the factory manual confusing as it jumps around from version to version and refers back to prior procedures for 3.4 I'm think based on my recollection from our class, the 3.4 was more particular for holding the cams. It appears to be not that important for the 3.6.

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Dan, we talked about using that timing tool as a cam hold down tool. It should work for the job (although the correct tool would be better, take Gary up on his offer). And you're right, doesn't matter on timing much for tear down. The hold down tool, or your time tool, will reduce uneven stresses from the lifter pressure (as stated above). The book directions you're referring to may just put the engine in a position to further reduce the pressure from various lifters. Maybe someone can chime in on that.

Be careful when you use this tool and you set the depth of the heads that go into the end of the cam. Years ago when I had my intermix and removed my cam covers I set them too deep and deformed the expansion plugs in the end of one cam (I should not that I was using a homemade tool at the time but you could do this with the factory tool if you have not careful). The result was that the expansion plug ended up popping out when I first started the engine after the fix. Could not fine an expansion plug of the correct size So i ended up taking all four cams to a machine shop and had the ends threaded and put in threaded plugs. These plugs popping out are one of the modes of failure that Raby talks bout and I would recommend having the cam threaded if you are rebuilding the engine or even just removing the cams for any reason.

Thanks for the replies everyone. I have the tool, I just wasn't sure procedure to use it. Seemed like an odd design of a special tool to have bolt heads sticking into the end of the camshafts. I guess it serves its purpose though.