CL77 oil filter wearing where shaft enters case

[coydogsf]

A little background. A couple years ago, I blew a clutch push rod seal on a rigorous multi-day ride on my '67 CL77. I chalked it up to excessive engine pressure due to hard use (and a few bad shifts on some challenging dirt sections). Still, I figured I should check the centrifugal oil filter for bits of plastic that could indicate a cam chain roller meltdown that might have clogged some oil passages. Luckily, it was pretty clean and an inspection of the upper cam chain roller showed it in decent shape. Somehow, that time I managed to check the oil filter through the small cover without removing the left crankcase cover and got the chain back on using LoudMouse's chopsticks trick.

BUT... now I wonder whether that tight access may have caused me to tweak something when I reinserted the shaft that the oil filter spins on back into the case. Cut to the present and another strenuous ride at altitude and again I started losing oil from the right side. I have not yet figured out which seal was leaking on the right, but again, I figured I'd check the oil filter for debris. This time, I couldn't get it loose through the access hole and decided to remove the left side cover.

What I found:

1) The shaft was tough to get out, and the oil filter would not spin freely on its shaft. It took a lot of work including sanding off some "melty metal" at the bottom of the shaft to get the top and the cup off the bottom. It was definitely binding on the shaft.

2) Where the shaft goes into the case, it appears to be wearing much more than I'd expect (see pic at https://photos.app.goo.gl/u7jqShMKDXkC8EQLA and closer look at https://photos.app.goo.gl/s8GcErgHvigh8BKe9).

Wondering if the shaft could have been spinning along with the filter (perhaps the pin at the top didn't "engage" with the notch that I think is supposed to keep it from spinning)? If so, it would have basically been working like a dull drill bit into the case. I know there has been lots of discussion/confusion about which end a washer is supposed to go on. I did *not* find a washer when I removed the filter and shaft. I have one now and my understanding is that it's supposed to go on the outside (washer, top, oil cup then shaft through all three), which wouldn't have really had an effect on this issue as far as I can tell.

Any insights from all you experts? I don't know whether to just put it all back together (with a free spinning oil filter/shaft I got off eBay) and the washer on the outside? Cleanup the "drilled" mess at the case first? Or am I in bigger trouble?

Thanks in advance for any advice (and for reading a long post)!

Dave

[LOUD MOUSE]

Please call me at 830-895-0654. .............lm

A little background. A couple years ago, I blew a clutch push rod seal on a rigorous multi-day ride on my '67 CL77. I chalked it up to excessive engine pressure due to hard use (and a few bad shifts on some challenging dirt sections). Still, I figured I should check the centrifugal oil filter for bits of plastic that could indicate a cam chain roller meltdown that might have clogged some oil passages. Luckily, it was pretty clean and an inspection of the upper cam chain roller showed it in decent shape. Somehow, that time I managed to check the oil filter through the small cover without removing the left crankcase cover and got the chain back on using LoudMouse's chopsticks trick.

BUT... now I wonder whether that tight access may have caused me to tweak something when I reinserted the shaft that the oil filter spins on back into the case. Cut to the present and another strenuous ride at altitude and again I started losing oil from the right side. I have not yet figured out which seal was leaking on the right, but again, I figured I'd check the oil filter for debris. This time, I couldn't get it loose through the access hole and decided to remove the left side cover.

What I found:

1) The shaft was tough to get out, and the oil filter would not spin freely on its shaft. It took a lot of work including sanding off some "melty metal" at the bottom of the shaft to get the top and the cup off the bottom. It was definitely binding on the shaft.

2) Where the shaft goes into the case, it appears to be wearing much more than I'd expect (see pic at https://photos.app.goo.gl/u7jqShMKDXkC8EQLA and closer look at https://photos.app.goo.gl/s8GcErgHvigh8BKe9).

Wondering if the shaft could have been spinning along with the filter (perhaps the pin at the top didn't "engage" with the notch that I think is supposed to keep it from spinning)? If so, it would have basically been working like a dull drill bit into the case. I know there has been lots of discussion/confusion about which end a washer is supposed to go on. I did *not* find a washer when I removed the filter and shaft. I have one now and my understanding is that it's supposed to go on the outside (washer, top, oil cup then shaft through all three), which wouldn't have really had an effect on this issue as far as I can tell.

Any insights from all you experts? I don't know whether to just put it all back together (with a free spinning oil filter/shaft I got off eBay) and the washer on the outside? Cleanup the "drilled" mess at the case first? Or am I in bigger trouble?

Thanks in advance for any advice (and for reading a long post)!

Dave

[coydogsf]

At LM's request, I've uploaded several new photos of the oil filter and shaft at https://photos.app.goo.gl/44N7LKiVyTtsstQf9

A few notes.

1) As I mentioned above, I did not find any washers when I pulled the filter. Parts diagram shows one I believe between the oil filter top and the aligning pin at the end of the shaft.

2) The O-ring pretty much crumbled when I pulled the top out. I have some o-ring cord that I was planning to superglue into a circle for a new one.

3) There is definitely a little "gash" in the bottom of the cup. Don't know if that's a cause or result of the wear on the case.

[LOUD MOUSE]

The "O" ring is available and if you don't find one I have them. .........lm

At LM's request, I've uploaded several new photos of the oil filter and shaft at https://photos.app.goo.gl/44N7LKiVyTtsstQf9

A few notes.

1) As I mentioned above, I did not find any washers when I pulled the filter. Parts diagram shows one I believe between the oil filter top and the aligning pin at the end of the shaft.

2) The O-ring pretty much crumbled when I pulled the top out. I have some o-ring cord that I was planning to superglue into a circle for a new one.

3) There is definitely a little "gash" in the bottom of the cup. Don't know if that's a cause or result of the wear on the case.

[coydogsf]

Okay, after a long and extremely helpful phone call with LoudMouse, we have a plan.

1) Redress the surface of the case (https://photos.app.goo.gl/EZaggDEiZRFjiZNRA). He described a sanding disc on what sounded like an air powered die grinder. I'm going to see what I can do with a Dremel and some Roloc sanding discs, starting with a rough grit and moving to fine. To make up for the material removed by the sanding (and dug out by the spinning oil filter!), his suggestion was to add a second *stainless steel* washer between the oil filter cup and the newly dressed surface of the case. Note that I'll also add the missing stainless washer between the oil filter top and the pin at the end of the shaft.

2) Replace the oil filter cup (https://photos.app.goo.gl/dKUkmsX1PpehZTHi8). Note the "gash" on the bottom surface, either caused by abrasion against the case or resulting in the wear on the case.

3) Consider replacing the 4" oil filter case cover (https://photos.app.goo.gl/p6BZHFWez9MM9c8q6). You can see the gashing on the outer ring, possibly another indication that the pin at the end of the shaft wasn't engaged into the case cover and at some point, the filter may have been flailing around in there! As far as I understand, it doesn't seem like this wear should affect anything in the future *as long as* I can be sure the pin will still engage/index properly in the case cover.

4) Replace missing O-ring and get everything fitting smoothly. The O-ring should live in the ridge at the bottom of the oil filter cap (https://photos.app.goo.gl/1Cohqfm8phirT96N8). LM puts a little white grease on the edges of the top and it should slide right in. The edges of my oil filter top seem to have some grooves and/or burrs that may need some smoothing for an easy fit. I'll also confirm this time that the filter (with top and washer installed) spins freely on the shaft. Finally, I'll make sure whatever case cover I end up with aligns well and slips into the left side case easily with just a smack from the heel of the hand to over-power the seal of the case cover O-ring. My current one is very temperamental to get in and out which has likely resulted in some excessive dings and screwdriver marks from both me and the previous owner.

5) Oh and finally, his eye caught another issue. Note how much the chain tensioner deflects the drive chain upwards just to the right of the sprocket (https://photos.app.goo.gl/NywzQ8cvWtwXVLTJ9). To him that was a sign of stretch in the chain.

I'll start on the tasks as time allows. Interested in any other insights anyone else may have but very appreciative of LoudMouse taking so much time to get me on the right path.

Dave

[coydogsf]

I finally got around to making some progress on this issue.

1) Redress the surface of the case (https://photos.app.goo.gl/EZaggDEiZRFjiZNRA).

I found an 1/8" shank Roloc compatible sanding pad (https://www.amazon.com/gp/product/B072M ... UTF8&psc=1) and some 1 1/2" sanding discs in various grits (https://www.amazon.com/gp/product/B07S4 ... UTF8&psc=1). After masking off as much of the case as possible to avoid shards of metal going everywhere, I removed the worn material back down to a flat surface (checking with sharpie to make sure as best as possible of where material was being removed by the disc).

Masked: https://photos.app.goo.gl/sHi8oekqnPeWnqKy8
The Dremel set up: https://photos.app.goo.gl/ujJeL6FJqUcDfZuK8
The results (before final leveling and polishing): https://photos.app.goo.gl/Q3cWcbqCPdZJJnuP9

On the inside between the case and the oil filter cup, I added a stainless washer to take up the space of the material I removed. I ended up having to use a thinner washer than I thought for the best alignment between the gears of the filter cup and the engine so the chain would run straight. https://photos.app.goo.gl/PAuAnBHovfBzBaga6

2) Replace the oil filter cup (https://photos.app.goo.gl/dKUkmsX1PpehZTHi8).

I did buy another cup and shaft on Ebay. When I tried to slide my cup off the shaft, there was a kinda melty burr at the bottom that prevented it from coming off the end. Despite sanding it smooth, the new shaft and cup just spun so much better and had no damage at the bottom, so I used those.

3) Consider replacing the 4" oil filter case cover (https://photos.app.goo.gl/p6BZHFWez9MM9c8q6).

With the new stainless washer on the end of the shaft between the indexing pin and the oil filter cup top, the filter will spin with plenty of clearance from the oil filter case cover (https://photos.app.goo.gl/PMngcs1APVs6vWYf7) and the indexing pin goes into the cover completely and relatively easily now (not yet fully inserted in this pic https://photos.app.goo.gl/Ce9DDWxX3vbv2rW48).

4) Replace missing O-ring and get everything fitting smoothly.

Note that in the short term, I made an o-ring (https://photos.app.goo.gl/LMjx5X49Wo56q6xn7) for the cup (yes, I'll order the actual Honda part number 91304259010). I also cleaned up the edges of the clutch case cover and the oil filter case cover that slides into it until (with a little oil for lubrication), the oil filter cover (when lined up with the screw holes and the metal locating cylinder) slides in smoothly and sets in place with just a whack of the butt of the hand (https://photos.app.goo.gl/sCAhvhz1GCBr4euZ9).

Got it all back together with a new clutch cover gasket and so far she's running decently (it's freezing cold here in the mountains so some further tuning while warm will be needed)

5) Oh and finally, his eye caught another issue. Note how much the chain tensioner deflects the drive chain upwards just to the right of the sprocket (https://photos.app.goo.gl/NywzQ8cvWtwXVLTJ9). To him that was a sign of stretch in the chain.

Now on to the primary chain replacement next time I get a window to work on it!

Dave

[fatboy98]

I bet that washer fell down behind the chain tensioner???