Removing the pivot pin for chain guide rail by accident :(

[dfoustou]

Dear all,

Τhis is a 1999 RS1100S. I removed by mistake the pivot pin for chain guide rail ☹ see diagram (bolts – labelled 1); and now I can’t push it in. Some very helpful peers in FB groups suggested to remove the valve cover and try to push the chain guide rail in alignment with the mounting hole on the cylinder while releasing the time tensioner.

Any suggestions are very much welcomed or what I should be careful with if I proceed as advised.

[Groceryrun]

I'm not really familiar with the engine.

Is it screw number 6 ?




If it is screw number 6 then maybe you can give the chain some slack by un-screwing the cylinder chain tensioner , part number 10 or 11.

[sirius815]

Definitely remove valve cover and do as Groceryrun says to create some slack. Should be fine.

[surfdad1060]

Its been awhile since I did it, you have to remove the screw to take the cylinder off, Hopefully you put a wire through the cam sprocket and the chain to keep it from jumping, take out the cam tensioner to put it back, replace the top tensioner with the updated one either from a later bike or I think wunderlich has them. I seem to remember you need a take apart ring compressor to put it all back together, sometimes known as VW style. The bolt on cam sprocket is super high and you need a hardened allen wrench plus a friend to stand on the brake to torque it. BMW was still doing factory workshop manuels back then somewhere I may have a cd rom. It comes in handy.

[surfdad1060]

I'm sorry at first glance I thought you were doing the top end. If your not taking it apart and just want to put bolt back you should be able to get some play by taking the chain tensioner out, the top one is kind of a ***** if I remember correctly but if its the original it should be upgraded anyway. Dealt with a lot on all of the oilhead forums. You may be able to get centered up with a small pick or drift.

[Groceryrun]

Looks like this has been resolved with the help of "dirtrider" of the BMWSPORTTOURING forum.

Quote from dirtrider :
Morning dfoustou

Did you remove just one side or both sides? Answering this question will help up determine how you should proceed.

In any case, start by removing the valve cover on the side (or sides) that you removed that pivot bolt from. You need to be able to see inside the cam chain pocket as well as manipulate the chain guide back into place.

If both sides were removed then you need to start on the side that has the lowest cam chain tension.

You will probably have to loosen or remove the cam chain tensioner on the side or sides you are trying to re-align the pivot bolt on. The cam chain tensioner is on the bottom of the cylinder on the R/H side & on the top of the cylinder on the L/H side (the L/H side tensioner is kind of a pain to access).

Quote from dfoustou :

thank you dirtrider for the prompt reply!

yes, only one - the L/H side.

Shall I also check the timing in case this has been changed? I am not sure how to do this in the correct way. The engine hasn't been turned.

Quote from dirtrider :

Afternoon dfoustou


If the engine crankshaft hasn't been turned then it didn't loose cam timing. With the L/H cylinder exactly on TDC compression the cam/to/sprocket key will be straight up (but unfortunately you can see that with the cam bolt in place) & one of the cam sprocket arrows will be pointing straight out.

But, the chain is fairly tight even with that guide bolt removed so unless the crankshaft was moved roughly or abruptly then the cam timing didn't move or migrate.

On getting the pivot bolt back in.

You might be able to line it back up without loosening or removing the chain tensioner (worth a try anyhow).

With the valve cover removed, try using a long screwdriver (or even two) to get the chain guide to move into position enough to get the pivot bolt started & back in. The bottom of the chain guide is slotted so the chain guide can move in & out but not up & down. So it is sort of in a fixed location.

You might even be able to get a smaller diameter rod (like punch or even a phillips screwdriver) inserted into the pivot pin bolt hole to line the chain guide up with the pin hole then hold it there with something (like a long screwdriver) while you screw the pivot pin bolt back in.

You just need to be creative until you can get it to line back up.

If you just can't get it to line up & stay there until you screw the pin back in then you will have to loosen or remove the tensioner. If you need to completely remove the tensioner & it is still the original BMW tensioner then be very cautious as the inner tensioner piston & spring can slide out then down into the engine as you remove it. So try only loosening it for a first try.

Added: on re-installing the valve cover, be very careful to not over-torque or over-tighten the valve cover bolts as they are VERY EASY to strip the soft alloy threads out of the cylinder head.

Quote from dfoustou :
Success!! The lower section of the chain guard rail was a little loose, requiring a slight upward push to allow the pivot to slide. I used a thin screwdriver for an initial guide to position the guard rail. There was no need to loosen up the time tensioner.

The valve clearance was within specifications. The camshaft gears next to the chain guard are also in alignment. I think that I am all set!

[njsax]

Originally Posted by Groceryrun

Success!! The lower section of the chain guard rail was a little loose, requiring a slight upward push to allow the pivot to slide. I used a thin screwdriver for an initial guide to position the guard rail. There was no need to loosen up the time tensioner.

The valve clearance was within specifications. The camshaft gears next to the chain guard are also in alignment. I think that I am all set!

Glad that it worked out. Thanks for posting the solution.

[dfoustou]

Originally Posted by njsax

Glad that it worked out. Thanks for posting the solution.

Thank you all for all the tips and advice. I apologize for not posting the solution. Thank you Groceryrun for keep the post updated.

These days I am dealing with a damaged gearbox:
https://www.bmwsporttouring.com/topic/110866-gearbox-messed-up-wish-me-luck/#comment-1195162

Yesterday I remove the sub-frame and final drive. Today I will remove the main frame and airbox. Everything went well yesterday with the help from pelicanparts forum and the service manuals (BMW, Clymer, Haynes). I took tens of pictures and I will post a concise review of the approach adopted for removing the gearbox.

[dfoustou]

Somehow I can't edit my profile. Thus, I am not getting notified about updates on this post.

[dfoustou]

The post has been updated. There has been progress!