Rocker arms, rocker arm shafts, valve gear, pushrod tubes; various parts of the cylinder heads,
 for BMW Airhead Motorcycles
© Copyright, 2012, R. Fleischer

Article 60
sub-section 6
headassy.htm

Adjusting valves & rocker end play, ETC!:   will be found in article #40
There is more top end information in article 60 section 5 and section 8.

I strongly suggest you read them!

Rocker Arm Shafts on BMW Airhead Motorcycles:

If your new rocker needle bearings have a flat end and a rolled end, the flat end is UP. Try not to disassemble the rocker arm shaft areas unnecessarily.....if pulled far enough out, some of the later models tiny roller needles may fall inside. They are located at each end, as a bearing, and the proper amount of them at either end is just enough so one more will not quite fit. The center area on the shaft is empty. Rocker shafts will have either a small round aluminum insert...used up to some 1982....or, an OFFSET punch prick, on some 1982...and all later ones. Both markings MUST face UP. The punch prick mark MUST also be outwards...that is, towards the valve cover....except that later shafts are angular drilled, and can be 180° reversed, when needed, to lengthen life.

Some late 1970's into early 1980's needle bearings were faultily made, and an end will fracture and needles will be found in the valve cover(s).  See AIRMAIL of September 2004.

There is a pricey update kit, to convert the rockers assemblies on the 1976 and later bikes to the 1985+ style that use shims.  KIT Part number 11-33-9-057-699.  You will also need support bushings 11-12-1-261-405 if you use the new style rocker arm assemblies.   You could use junked heads from 1985+ to provide the parts, or swap the heads if in good condition, or rebuildable, etc.   The mentioned kit includes the fin quieting pads (article elsewhere on this site).  Don't try this with the early /5 heads, it won't work.   MANY folks upgrade the earlier bikes to later items in a piecemeal fashion....such as the later pushrods.  The 1985+ models, and fully kitted early models, adjust their end clearances by means of shims. These rocker units have a pressed-in plastic part that quiets noises.     The SI bulletin is from May 1986, and is 11-032-86 (2208).   I can supply any individual part number for you.   

Updating a /5 Airhead rocker gear: 

 First, as noted above the 1985+ rockers, kit, etc., won't fit right out of the box...although they can be made to work.  There are TWO types of these early heads.   If yours has steel tubes pressed through the fins, next to the spark plug (both sides), these tubes go into the cover area, the rockers are on them.  You will need the round spacers that fit the tubes and push against the O-rings, pushing them into the head.  Otherwise you will have oil leaks. Use the 1974-1975 needle bearing rockers.    There is a later /5 head that the tubes did not show through, and these don't use the O-rings, nor spacers.  For these you can use the later rockers and parts up to 1984.   The later ones had better heat treated tips.      BE SURE to see the photos and notes on the /5 here:  http://largiader.com/tech/rockers

Aligning the rocker gear on a /5 Airhead motorcycle:

NOTE!:   /5 models with original valve gear need extra care to align the rockers/shafts/blocks assemblies.  There is no locating step machined into the rocker blocks.   These parts can all be moved about a fair amount if the rocker hold-down nuts (head nuts) are loosened.   Clymer's, Haynes, and even BMW's literature, shows an alignment tool that can be machined-up, but this tool really does NOT do what is promoted.  Alignment of the rocker gear is done every now and then during valve adjustment time....by squeezing together the rocker blocks lightly, and then positioning the pushrods in the bores, and keeping an eye on the rocker tips where they contact the valve stem (offset is proper, for valve rotation).   In any event, the /5 rockers have a pressed-in bushing, and the bushings wear, as does the shafts.  
Here is a trick to quiet those worn rockers!
   1.  Replace the worn bushings in the rockers if truly bad.
   2.  If NOT worn terribly badly, simply SWAP the rockers; ...but do NOT move the rocker shafts from their particular position:
        a.  move right cylinder exhaust rocker to the left cylinder intake
        b.  move right cylinder intake to the left cylinder exhaust
        c.  move left cylinder exhaust to the right cylinder intake
        d.  move the left cylinder intake to the right cylinder exhaust

NOTE that most /5 cylinder heads require O-rings at the rocker boss area, where they fit into the head.  Heads requiring these (8 per 2 heads), part 11-12-1-255-167, which became 11-11-1-460-470, and then probably 11-11-1-460-391, can be told from the OUTside by looking for the tubes, in between the fins.

Rockers, in general: