HELP!!! Removing Head on 280SL

[ALP]

Hi:

I need help please. I have read everything I could find on our site (and others) but cannot quite find the right answer.

I am removing the head on a 1971 280SL.  Before I started I set everything to TDC.  So the cam is set such that the lobes on cylinder one are at 10 and 2 and the mark on the pedestal matches the mark on the sprocket.  The rotor on the distributor is pointing at the notch on the diistro body and the crank pulley has the timing marker aligned at the zero degree mark on the pointer.   So I think everything is TDC?  Right?

Much of the engine is already dismantled.  Here is what I have removed so far:

--valve train cover
--intake and exhaust headers
--cross over linkages
--injector lines
--all the various hoses and tubes and electricals that run into and out of the head
--thermostat housing
--timing chain tensioner (the tensioner sproket and arm are still attached to the head)
--timing chain guide (upper)

The problem I have is this:  I cannot figure out the best way to take off the timing chain.  This is not a question of cutting a link.  I have read all the forum discussions about doing that process.  But I am not changing my chain.   I just want to get the chain off the cam sprocket so I can pull the head.  Removing the tensioner did not give me enough slack to remove the chain.  I am afraid to try to loosen the cam sprocket bolt because (1) if the cam turns I will lose my TDC alignment on everything and (2) I have read in the forums (I think from Joe Alexander) that it is a really bad idea to turn the motor using the cam sprocket nut.   All I really need to know at the moment is what to remove next to give me enough slack to remove the chain from the various sprockets so I can then remove the head.  I want to support the timing chain in place as I remove the head so that the chain stays properly in place in the lower end of the engine.  

If the suggestion is to remove the cam sprocket, what is the best way to wedge the sprocket so that it does not move when I start turning the socket or wrench counterclockwise to remove the bolt (I assume I am going counterclockwise, right?))

Any and all comments would be appreciated.  I apologize if this seems elementary but I really do not want to do something that makes me end up having to replace or rethread the timing chain.

Thanks,

Andy
(Honolulu)    P.S.  When I go to reassemble the chain tensioner, how do I bleed it?   I know this is important, and it has been mentioned a lot in the forums, but I could not find any suggestions as to how to actually do this step.  Thanks

[ja17]

Hello Andy,

Just remove the large 22mm bolt holding the sprocket on the camshaft and take a soft mallet and tap the sprocket off the end of the camshaft. Be careful not to drop any parts into the chain gallery. Once the sprocket is removed the chain can be lowered into the chain gallery without being split apart. Tie a wire on the chain for easy recovery later.

[ALP]

Joe:

 Is it going to hurt anything if the cam and engine turn as I am tapping the 22MM bolt loose?   Also, looking at the engine facing rearward, the bolt comes off counter-clockwise, right?   Thanks for your help.

Andy

[ja17]

Hello,

Yes, counterclockwise from the front. No problem if the engine should turn a bit. You will need to adjust  crankshaft at TDC once again for installation.

[ALP]

Joe:

Thanks.  It only took a couple of light taps and the nut broke free and spun out no problem.  I then knocked the cam sprocket from the rear with a small rubber hammer and it slid off nicely.  It was easy.  Thanks much for your help and advice.

Andy  P.S.  The tip of a finger of a surgical glove ripped off and dropped down the chain gallery as I was packing it with rags.  I got it out but it was nerve wracking!!