Motorcycle Repair: 1989 FLHTC - Oil blowing past Rocker Box, rocker boxes, rubber gasket


Question
QUESTION: I recently had the top end of my 89 FLHTC rebuilt. During the break-in period, everything seemed Ok, except for a bit of lifter knockage. The mechanic that did the work wanted to drop 50W oil in the engine to quite the lifter noise, and at roughly 700 miles after the rebuild that's what he did. However, when he was changing the oil, he primed the oil filter with Primary oil, dumped 2 quarts of 50W oil in the oil tank, and added one quart of 30W and said it was ready to go. He said everything would be fine, but after 20 miles (when it was good n hot) I had oil spewing out of the bottom of the rear cylinder rocker box, and the lifter noise was louder than ever. After I got it back to his shop, he said that it was a pinched rocker box gasket, but if this were the case I would have had oil spewing during the break-in period, correct? I have been checking around and everyone has a different answer - from replacing the rocker box seal with cork to replacing the rocker box spacers (maybe they are warped) to replacing the rocker boxes with 93 - 94 EVO rocker boxes. Also, the mechanic wanted to cut the adjustable push rods out with bolt cutters and replace them with quick change push rods to silence the lifter noise - I am confident that the adjustment can be made to the adjustable push rods, so long as the guy holding the wrench knows what he is doing. What does your experience tell you about all this? What is your advice? Thanks ...

ANSWER: First, you cant mix primary fluid with oil. Primary fluid is synthetic and the oil he used is not. Next, you shouldnt run 50w oil in a EVO motor. Its to thick on startup.
You could have had a pinched rocker box gasket and it just started leaking by chance, so I would replace it. If your rocker box center ring was warped, then it would leak as soon as you started the bike. I would stick with the rubber gasket, cork over time will break down.Stick with your stock rocker boxes.
Now to the pushrods. Changing the adjustable pushrods with quick change pushrods will do nothing for the noise. Your changing one adjustable for another adjustable pushrod.
First thing I would do is repair the leak. then start the bike and let it warm up and change the oil to 20w50 as well as the filter. On the pushrods I would make sure they are adjusted right. If not then they can make noise. If you need to know how to adjust them yourself, let me know
Good luck and happy riding
Mike

---------- FOLLOW-UP ----------

QUESTION: Thanks for the quick response. I had someone call yesterday and said they could eyeball the rocker box being warped. If it were bolted down properly I would have to say that would be something next to impossible to eyeball.

I am guessing that the upper rocker box gasket is much easier to replace than the lower rocker box gasket. What steps do I need to take if the lower gasket needs replacing? Where can I find the torque specifications to torque the rocker box back down? If the rocker box is warped, how can I really tell? If it needs to be replaced, can I just replace the rear rocker box, or do I need a set? And finally, can you provide the steps I need to take to adjust the push rods?

Answer
I have never heard of anyone being able to eyeball a warp! You can remove the rocket box and put it on a piece of glass and it whill show the warp. You can just buy the part that is warpped. You dont have to buy a whole set.
Since you are planning on doing the work yourself, you best bet is to get a service manual. In it you will find the steps to do the work, the torque specs and how to adjust the pushrods.
Good luck and happy riding
Mike