camshaft sprocket not going back on

[220sebCoupe]

Hi everyone, i have read thisforum for a long while now, but this is my first ever post. I am putting a head back on a m127 engine, w111 chassis, not a w113. The head has just come back from the machine shop and i cannot get the thrust washer or camshaft sprocket back onto the camshaft. The very nose of the camshaft is 28.14mm but the restof the nose is 28.04, like the end of the camshaft has flared out. I had no problems taking the sprocket off, and even put it on and off a few times before taking the head to the machine shop. I am at a loss, has anyone ever come across this before, i am assuming that this should be a neat fit, not a press fit.....lots of head scratching going on here!

[ja17]

Yes, it should  fit on without any problems. You may have to "clean-up" the end of the cam if it is flared out. Try a fine metal file, or take it to a machine shop who can turn it down lightly.

[GGR]

Someone may have dropped the camshaft on the nose. Once you have it back in place, make sure it turns freely in its towers.

[220sebCoupe]

thanks for the responses, I suspect it was hammered on at the machine shop, but cant see any reason why that would have happened, I was suspecting it was dropped too, but there is no other evidence of this. Thanks JA for the filing advice, I was heading down that path but want to see if anyone would suggest never to do such a thing. will let you know how I get on.
All the best

[jpinet]

I would definitely bring this back to the machine shop who did the work to let them correct this. If anything goes wrong when you are playing with it, or if there is something wrong with the camshaft (someone dropped it) and you've altered it in any way, they can say it's now your problem. If they did something that flared the end of your camshaft, they should correct this.

[220sebCoupe]

I agree with the sending back to the shop sentiment, but I'm being lame - it's 1.5hrs round trip to the shop. A friend came around with some oil stones and spent a very patient couple of hours slowly filing down the very end of the cam. It also became clear that the end of the cam had been hit or drop causing the issue in the first place. It's back on, tighter than it was previously, it's round and the sprocket ran true. But it was only after waking up this morning that I realised I have to take it off again to put the timing chain back on, one step forward etc.

[Benz Dr.]

Getting something back together is half the battle - making it work is all of the war.

[220sebCoupe]

Thanks for everyones responses, the head is back on and a new timing chain has been installed with valve clearances checked. I went to pump up the, newly purchased, chain tensioner this evening and cannot get it to take in oil, i can pump the tensioner spocket with only minor resistance from the tensioner spring. I have kept the oil well full, although the level is not going down, and have tried slow releases and fast releases and a combination. I must have pumped it 50 or more times with no change in resistance. Is there a method i'm missing or whe  the BBB say slowly release, do they mean over 10 or 20 minutes. Oh, and swearing at it and cursing it's mother made no difference to the result. I have contemplated kicking it, but thought i would come back to the lounge and write this instead.

[ctaylor738]

The tensioner sits in a little pocket that you fill with oil.  Then you prise the lever on the tensioning sprocket to allow the tensioner rod to move out.  The oil in the pocket should flow into the tensioner and allow it to hold the chain tight.

[ja17]

Normally, they will just pump up as long as the well is full. On rare occasions the tensioner can be difficult to prime-up, especially if it is a new un-used unit. The BBB shows a method of priming them. Remove the tensioner, submerge it in a container of oil and pump it with your hand until in primes-up. If you still cannot prime the tensioner, dismantle it and check to make sure the ball check is not stuck. Be careful not to loose the tiny ball. I hope you do not have factory AC. If so the tensioner is a major job to remove since the AC "monster" bracket is in the way.

[220sebCoupe]

thanks once again for the responses, JA, this is a brand new tensioner straight out of the box, so I'll go with your suggestion and pull it all out again and see if I can prime it on the bench. Just a bummer that I had already installed the thermostat housing and hoses etc, so all that has to come out too, I'll let you know how I get on. no factory AC though, so easy enough, just undoing last nights efforts that's all.

[220sebCoupe]

Solved the tensioner issue, i used the ball bearing and seal from the old tensioner and it worked just like one bought from a shop, apart from the fact that i had already bought one from a shop. So the new one just wasnt quite right. Onwards.