Carrera chain tensioner upgrade question

[dberman]

I'm in the process of upgrading to the carrera chain tensioners. I still have the original mechanical ones that came with my 83 SC. My question is the following. I removed the old tensioners and put in the new ones. However, I notice that there is quite a bit of play in the chain wheel support. I can push it maybe 1/8 of an inch in either direction. So, the piston on the tensioner doesn't always sit all the way on the arm that it pushes against. Depending on the position of the chain wheel support, the piston can either be totally on the arm or 1/4 of the piston can be hanging off the end.

My question is should there be that much play in the chain wheel support? The only thing I did was remove the old tensioner and slide on the new one. I checked and the old and new tensioners and they seem to be exactly the same size. I also checked to make sure the tensioner slid on all the way on their spindle and the bolt is tight. Both the left and right side tensioners have this same behavior. Unfortunately I should have done one side first and then checked the other side with the old tensioner to see if this was the same as before.

Thanks for your help.

Dave

[James Brown]

Did you remove the pin? They work with oil pressure so on start up they should pump up.

[James Brown]

Don't let this stop you from performing this upgrade though - it is very useful, and very worthwhile for ensuring the longevity of your engine.* The key to remember here is to make sure that you do not let tension off of the chain at any time.* Keep the tension on the chain by making sure that the idler sprockets are tight against the chain.* If you are replacing your idler sprockets, then keep tension on the chain by tying it tight. * DO NOT LET THE CHAIN GO SLACK AT ANY TIME.* Following this simple rule should make this upgrade uneventful.

If the chain does happen to slacken up, then you need to check your camshaft timing (documented in 101 Projects for Your Porsche 911).* A good check too before you close up your chain tensioner housings is to make sure that when your engine is at TDC (Top Dead Center), the dot or '930' mark on the two camshafts are facing upwards.* Spin the engine clockwise with the chain covers off just to make sure that there are no problems with the chain.* This is a good last-minute check to make sure that everything is okay.

Make sure you follow the instructions to the letter

[4sd911]

Yes there will be some play between the idle arm and tensioner.

[dberman]

Thanks for the replies. Yes, I did pull the pins. I also had tied the chains together when I replaced the tensioner to make sure there was no slack. I only replaced the tensioner so I didn't have to muck with anything else.

I've included a picture. What I am seeing is that there is a gap at point B and I can reach in with my hand and move the wheel to close or open that gap maybe a 1/4 of an inch. Also when the gap is closed, the head of the tensioner isn't completely on the arm. I'm referring to point A in my picture. When the gap is closed maybe 1/3 of the piston is not touching the arm.

Does this seem correct?

Thanks,

Dave

[Gunter]

Both the tensioner and the idler arm will have a small axial float on the shaft during operation but they cannot go anywhere because the cover will limit the axial float.

Once the pin is pulled, the tensioner should expand even without oil pressure and reduce the slack in the chain. Is that happening?

Here is what I'd do:
Once the cover is on, install the small oil line to the tensioner but leave the banjo fitting slightly loose. Disconnect the plug under the 6-pin module to disable ignition, then crank the engine to get some oil pressure which will push the air out of the small line causing a little leak at the banjo. Stop cranking and tighten the banjo fitting. Not too hard, just enough to seal. Reconnect the 6-pin module, start the engine and check for leaks in the lines.

[dberman]

When I pull the pin everything is tight as it should be. It just seemed strange to me there was so much play and that the piston wasn't centered over the arm. I guess it is ok.

I put everything back together and the car is driving fine. I have a small oil leak that I have to chase down but other than I'm good. I imagine if something is wrong with the tensioner setup I might not find out for a while.

Thanks for all the help. It is much appreciated.