380 Timing Chain Installation Problem.
 

Hi all, I bought an 1980 380 SL and found that the engine is badly in need of a new timing chain. Having quite a bit of mechanical experience, including rebuilding an 911SC engine, I read the Peach Tree technical article which seems straight forward and went ahead with the project. The engine was free turning and had good compression when I started. To turn the engine over easier, I took out the tensioner which in retrospect looks like it was a bad a idea. Now,
as I turn over the engine with a wrench, I am getting piston interference even though I put the tensioner back and all 3 timing marks line up. I haven't changed chains yet.
Any ideas?
Thanks, Joe.

Do you have a manual?
 

I replaced my chain years ago. I don't recall the specifics, but I had the MB paper manual and it was very detailed. That same manual is available for free from MB at startekinfo.com.

Yes, I do have the manual. What I think happened is when I took out the tensioner I heard a loud ka-chink as the chain went slack. Now it is kinked and stuck behind the chain cover.

M116 chain replacement
 

When I replaced mine, I upgraded to the dual chain so I had to remove the front cover. One of the plastic guides broke so I had no choice (MB recommended the upgrade anyway). I don't know if you have the single or double chain, but if it is a single you may want to think about the upgrade. It wasn't that much harder and you replace all of the guides.

Re-look at 05-320. You are supposed to remove the tensioner to change the chain. With the engine at TDC on the #1 cyl, both chain sprockets should line up to the marks. If you suspect that the timing is off, then look at 05-215.

You probably broke a chain rail when you removed the tensioner, and the broken part got wedged somewhere between the chain and a sprocket.

To turn the engine over easier, remove the spark plugs.