XJ XJ8 / XJR ( X308 ) 1997 - 2003

Secondary Tensioner Replacement Pics

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  #21  
Old 03-13-2011, 11:15 PM
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The tie-wrap just takes the place of a "buddy," if you don't have one handy. And there is evidently some finesse required when carefully removing the cam bearing caps, so as to not crack the camshaft in two. But yes, this general method is infinitely easier than the factory way.
 
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Old 03-13-2011, 11:38 PM
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I read another article about marking reference points on the timing chain links and cam sprockets teeth. Marking with white-out (used to correct cover area of text on a written page) the multipoint positions of the timing chain. Mark the chain link and the sprocket tooth the link is on (both the intake and exhaust cams).
This could help ensure that the timing is not thrown out of its correct position.

Ok --- What are your thoughts on this?

Jim Lombardi
 
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Old 03-14-2011, 10:25 PM
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Originally Posted by jimlombardi
I read another article about marking reference points on the timing chain links and cam sprockets teeth. Marking with white-out (used to correct cover area of text on a written page) the multipoint positions of the timing chain. Mark the chain link and the sprocket tooth the link is on (both the intake and exhaust cams).
This could help ensure that the timing is not thrown out of its correct position.

Ok --- What are your thoughts on this?

Jim Lombardi
Whatever method you choose, it would be a good backup. However, it should not be your only locating method.
 
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Old 03-15-2011, 04:33 PM
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Marks on the sprockets sounds good, but It just sounds like a disaster to me. Read a post the other day about a guy having to replace a cam shaft because one of his snapped while tightening saddles. Rgardless of what you do, you're going to have at least one set of lobes on each side pointing down. I had to put a wrench on center of a shaft just to rotate it flat fore the cam lock tool. I imagine this kind of back pressure didn't help the guy that snapped his shaft. Specs for tool are online and a piece of angle stock and three bolts from Lowes are all you need.
 
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Old 01-05-2012, 05:28 PM
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Default exhaust cam

So is the exhaust cam the that needs to be loosened the one thats farthest from the intake, makes since that it would be closest to the exhaust manifolds. I'm trying to replace the secondary tensioner the easy way.

Thanks!
 
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Old 01-05-2012, 06:19 PM
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There are any number of posts on this subject with pictures. Got any specific questions?
 
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Old 01-06-2012, 07:37 AM
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Is replacing the the secondary tensioners the easy way by lifting the cam after all lobes are facing up, ziptying the chain to the sproket the best way to do it?

Do you know what the tourqe rating for the cam bearing caps are and the sequence for screwing them down.
 
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Old 01-06-2012, 10:27 AM
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I would think that it could be considered more difficult since you are carefully removing 16 bolts holding the cams down. The issue is that the zip tie method avoids obtaining the cam alignment tool. I would think that the key word is 'alignment'. With the tool set you know when you are through that the crank and cams are exactly in time.
 
  #29  
Old 01-06-2012, 11:28 AM
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In the absence of the proper tools, you can use a 6" ruler to lay across the cam flats to check that they are perfectly aligned with each other, with a crank position pin in place.

It seems that a lot of people use the zip tie method, and I admit to doing it once myself, however having the lock down tool and the pre-tension tool would be better. I am not sure what the real experts like Brutal or Motorcarman would say, but keeping the proper pre-tension on the chains is a point worth considering.When the camshaft is lifted off, you obviously release the pre-tension. When bolting it back down, in theory I guess you put the chain back to its former tension, provided that you have the cam flats in the same alignment they were in prior to removal. I would use that 6" ruler before dismantling to ensure that the cams are in the correct timing position with the crankshaft pin in place. I have heard some people ignore the position of the engine and simply pull the cam and replace the tensioner. I guess that is OK... provided the engine does not move. I think the tension of the cam lobes on the followers on the side that is still assembled, can be enough to roll the engine back slightly, despite having the crank pin in place through slack in the chain system. I also seem to recall that the chain tension on the passenger side (North American) may back off slightly after torquing everything back in place, due to the cam lobe pressure on the followers. One other note is that there is no need to remove the spark plugs, which would make the engine roll easier. This is all good, provided there is little or no chain stretch in the system. That 6" ruler across the flats prior to camshaft lifting may help indicate chain stretch.

All in all, I agree the zip tie method is better than letting a failure occur but proper alignment and pre-tension is better yet.
(in my humble opinion)
 
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