Excellent post and lots of pics on another forum.
Timing Chain Replacement on My 560SL - PeachParts Mercedes ShopForum
Timing Chain Replacement on My 560SL - PeachParts Mercedes ShopForum
I stand to be corrected by those who heard a definitive faulty chain, I thought it should be a sound smilar to that of a bit loose motorbike chain, somewhat slapping, somewhat grinding, a bit ticking but quite distinctive from tappet noise.:thumbsup:
That might explain the knocking sound (reminiscent of a noisy tappet) my '80 450 makes on start up. Time to get a second opinion (form someone who isn't tone-def, like me).
This one is also useful:Excellent post and lots of pics on another forum.
Timing Chain Replacement on My 560SL - PeachParts Mercedes ShopForum
It is also in the "This Damned Old Car" sticky.
When checking this it is very important to make sure the engine is only rotated clockwise (looking at the engine from the front) until you reach TDC. If you overshoot TDC you will have to rotate back about 20 degrees and then re-approach TDC clockwise. Good idea to also put counter clockwise pressure on the right cam shaft while rotating the crank clockwise, as the cam has a tendency to rotate ahead due to valve spring pressure.I have a friends car in the garage, '84 380 SL with 81000 miles on it.
I remove the right v/c and lined up the sprocket mark with the pedestal mark and the crank balancer showed 8 degrees retarded. I ordered a new chain and rails. I installed the chain using Peachpartwiki thread, all went well however when I was done I lined up the marks again and the crank read 8 degrees retarded (haven't put the rails in yet). I removed the left v/c and rotated the engine and lined up the left side, the crank read 0 degrees but had to move it some more to line up the right cam (8 degrees on the crank).
Is it possible the ilder sprocket in between the cams has a bad bearing or is worn?
If I move the cam sprocket one tooth it will advance the cam too much.
Any ideas, has someone run into this before.
David J
What's the status of your tensioner? Is it extended, or collapsed?I double checked it tonight and came up with the same results. If I keep pressure on the the right cam it would show more degrees retarded wouldn't it?
I haven't removed the timing cover and I think I am going to have too to see what is happening in there.
David J
I have a friends car in the garage, '84 380 SL with 81000 miles on it.
I remove the right v/c and lined up the sprocket mark with the pedestal mark and the crank balancer showed 8 degrees retarded. I ordered a new chain and rails. I installed the chain using Peachpartwiki thread, all went well however when I was done I lined up the marks again and the crank read 8 degrees retarded (haven't put the rails in yet). I removed the left v/c and rotated the engine and lined up the left side, the crank read 0 degrees but had to move it some more to line up the right cam (8 degrees on the crank).
Is it possible the ilder sprocket in between the cams has a bad bearing or is worn?
If I move the cam sprocket one tooth it will advance the cam too much.
Any ideas, has someone run into this before.
David J
Things will be tight for the next few days but I will see if I can get the timing cover off and take a look inside.
First check to see that you don't already have an offset key installed. Keys are available up to 5° at the cam = 10° at the crank. Sounds like you may need a 4° key. Other things to check: Sprockets for wear. See if the sprocket has a part number and check it against the EPC. Check sprocket and cam key ways. Check that the current key way is not already half sheared.The tensioner is extended and the chain is tight.
I rotated the engine to line up the cam mark (right side) clockwise very carefully, did not have to back track then I read the scale on the damper.
I may have to go with offset keys, where can I get ahold of them?
Things will be tight for the next few days but I will see if I can get the timing cover off and take a look inside.
David J