'90 300E 3.0L timing chain tension
09-06-2007, 02:53 PM
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'90 300E Blk/Tan
'90 300E 3.0L timing chain tension
Just got the rebuilt head back and am putting the engine back together now. I have a question on the timing chain tension.
During the disassembly process we took the gear off the cam and bungied it to make sure that the tension was maintained and the chain didn't move. That worked out fine, but the timing chain tensioner seemed to creep out a bit, putting more tension on the chain. I removed the cover plate and spring to try and move it back (you could plainly see the oil line on the plunger cylinder) but it would not move back to where it was without adjusting the bottoming ring outwards just a bit to slacken it back to where it was. I had to slacken it just a tad in order to get the gear back on the cam correctly (don't worry, we marked everything very well before removal.)
Now I am wondering what is the correct amount of tension to have on the chain before I close the cover up. Can anyone give me an idea how tight the chain should be before I close up the cover ?
During the disassembly process we took the gear off the cam and bungied it to make sure that the tension was maintained and the chain didn't move. That worked out fine, but the timing chain tensioner seemed to creep out a bit, putting more tension on the chain. I removed the cover plate and spring to try and move it back (you could plainly see the oil line on the plunger cylinder) but it would not move back to where it was without adjusting the bottoming ring outwards just a bit to slacken it back to where it was. I had to slacken it just a tad in order to get the gear back on the cam correctly (don't worry, we marked everything very well before removal.)
Now I am wondering what is the correct amount of tension to have on the chain before I close the cover up. Can anyone give me an idea how tight the chain should be before I close up the cover ?
09-07-2007, 12:16 AM
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89 300TE, and 68 280sel
Ugh, I did this job on my brother's CE, it was a load of fun. You need to release the chain tensioner that is near the alternator in the engine block... but what you really need is the factory manual to tell you the sequences as well as the method to allign the cams and the variable cam sprocket... if you don't get it just right, you are F'cked.... or your motor is.
09-07-2007, 09:44 AM
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'90 300E Blk/Tan
This is the SOHC engine. We marked the cam gear/chain/pin alignment before we removed the cam gear. We kept the tension on the timing chain while the head was off. All we should have to do on reassembly is line those back up and bolt the cam gear back on. Unfortunately, the cam tensioner jumped out a grove and put just enough extra tension on the chain that we could not quite get the gear back on without slightly backing off the chain tension just a tiny bit.
10-31-2007, 01:30 PM
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'90 300E Blk/Tan
Update
Took the timing chain cover back off, since it was leaking oil, and replaced the chain tensioner. PITA, but easy. Learned to use a small amount of silicone on the timing chain cover to help seal it. The gasket alone leaked on mine, and I carefully made sure that ALL surfaces were clean.
