Changing Push Rod Tubes

[takefive]

Has anyone had the pleasure of changing the push rod tubes before??
Since I have the cylinders off and the tubes are all rusty and nasty looking, I thought I would change them. I bought the new tubes and the drift. I bought Ed Korns Video's, and that shows him punching out the tubes, but unless I missed it the are no details on installind the new tubes. I am guessing that they have to set in at a given height in order for the ring to seat the rubber seal into the case properly. But I dont want to punch out the old ones untill I have a handle on the job, Is there a lip or stop inside the cylinder to seat the tube against or what????
Regards
Graham

 

[20774]

I don't believe there's any such lip. Try and take some measurements from known points as a reference for installation. My mechanic just installed them to a specific distance that he just "knew". When I installed the cylinders and before the heads went on, I used my drift to drive the tubes in some to put a little more pressure on the pushrod tube seals. So, you might want to install the new ones a little farther away from the block which will allow you to tap them back in to get the pressure on the seals.

 

[takefive]

Thanks Kurt
What are your thoughts on engine oil weights for these old Ladies?
I'm partial to Castrol, and our ambient temperatures are generaly over 80f. I've seen some threads on detergent v/s non detergent, are there any no-no's that you know of??
Regards
Graham

 

[20774]

Graham -

I try not to get hung up on some of the arguments regarding oil. It's a can of worms when you consider the time when the bikes were made and what was available for lubrication. There are also issues with the bearings used in these engines (roller bearings) as opposed to the new bearing surfaces. Today's engines rely on sliding with a metal film in between...the old engines really want the bearings to roll. That's about as much as I know about that...

I'm a dino man and try to use the best quality oil I can. My choice has been BMW oil after a number of oil analysis articles were published in the MOA News quite a few years ago. The issue that I picked up on is the level of ZDDP, an anticorrosion and antiwear additive that is lacking in some of the later oils. This was dropped because it did damage to car catayltic converters, since the oil companies are catering to the larger markets. API ratings of SG still have appropriate levels of ZDDP in them while ratings of SL, SM, etc., do not. BMW still sells oils with this rating, as do other manufacturers.

The other thing that I'm toying with is the use of multi-viscosity oils. The owner's manual says to nominally use a 40W oil in the summer, mostly what I have in South Texas. I've been using 10w40 but the 40 component is achieved through still more additives. The oil is basically 10w stock with the additives to make it like a 40w when it gets hotter. But these additives break down over time, so the 40w shifts back to say 35w or even lower. I'm contemplating going to 20w50 since the temperatures here can probably handle the higher 20w in the colder part of the year and then as the oil wears, the 50w will become 45w or 40w.

Bottom line, I think it's best to use a quality oil and change it frequently. I suspect the bike will outlive me. I just had the slingers cleaned and doubt I'll ever have to do it again as long as I will be riding it.