Topic: Aluminum sparkles in oil: Where all could they be from?

[ksteve]

Where all could aluminum bits in the oil come from?

-Camshaft journals
-Cam chain rubbing against tunnel
-anything else in top end?
-anything in bottom end?

I posted a thread earlier about ferrous metal in my oil filter here: http://forums.sohc4.net/index.php?topic=111682.0

I did as several members suggested: drop sump, change oil and filter, adjust cam-chain tension, ride and re-check. I rode  for 10 miles and took off the filter. It had metal sparkles and filings in it again, but this time almost all of it did NOT stick to a magnet (i suspect the earlier slurry was both). There were also bits of black stuff.

Here's some that I wiped out:


I pulled engine. My aluminum cam-tower-bearing journals are fine.

The tunnel shows signs of chain rubbing on both sides:


The tensioner rollers are pretty hard, with bits broken off (the black stuff?):


But I adjusted the tensioner long before the problems, so I'm worried there may be another source of aluminum.

Where else might it be coming from? I'd rather not split the cases if there's nothing down there that could spew aluminum.

[ekpent]

It may take a couple of oil changes down the road to totally clean up all the bits as there are many reccesses in the lower end to trap that stuff even after draining.Was there only a minimal amount this time compared to the last or do you still feel it was excessive.? Looks like you identified a good rub there as a problem source.

[ksteve]

It may take a couple of oil changes down the road to totally clean up all the bits as there are many reccesses in the lower end to trap that stuff even after draining.Was there only a minimal amount this time compared to the last or do you still feel it was excessive.? Looks like you identified a good rub there as a problem source.

There was quite a bit. At least it seemed like quite a bit for just 10 miles' running.

Maybe I over-reacted in pulling the top, but I began to worry that my cam towers were eating themselves up or that my tensioner rollers were toast.

Too late, now: I have to get top-end gaskets, seals, new tensioner etc.--if I decide there's no other likely source of aluminum.

[ekpent]

When a cam and towers go it does produce a ton of flak. Glad those look good and now you will have peace of mind on that aspect at least.Lets see what some others may say as possible other sources.

[ksteve]

When a cam and towers go it does produce a ton of flak. Glad those look good and now you will have peace of mind on that aspect at least.Lets see what some others may say as possible other sources.

Thanks for the encouragement!
Should I replace the cam chain, since I now know it was flopping and grinding against the wall?

[mrrch]

Can the primary chains rub on the cases if stretched?

[ksteve]

Can the primary chains rub on the cases if stretched?

Good question; maybe an expert can respond.

I checked the primary-chain tensioner clearance per the Honda manual and it was within tolerances. And the primary rubber roller is surprisingly supple and undamaged (perhaps because it was submersed in oil for so many years). But of course, I can't examine the surrounding case unless I split it.

[PeWe]

Check the clutch. I had problems with my engine (twice) when the outer clutch fiber plate was of wrong model, same as the other and therefore broke.  The outer plate must have wider tabs to match the basket.

One piece of broken fiber plate circulated in engine and crated small pieces of alu and some black rubberstuff, probably from the tensioners.

[craywm]

yeah id pull of all the little side covers. does your starter act funny? it could be something down that ally.. but it also could just neeed to be run to mix up the oil then change it to get all the suspended bits of metal out of it. then check it to see if its still full of metal in a few more miles. change the filter too. that will help. personally i like to pull of all the outer covers before taking an engine down. just to see if it could be anything in there. this happened to me once on a cbr600. solved the problem through a side engine cover. if you didnt rebuild the engine last its always good to get an idea of the skill level of the individual who did by seeing their work.

[wrenchmuch]

That material you found in the filter followed a path from the sump, through the scavenge side of the pump, through the transmission and to the oil tank, and back to the delivery side of the pump. You should remove your oil tank and flush it out. Pull the oil pan and clean it. While the pans off remove the pump and replace the seals and o rings and check for proper pump rotor clearances as well as damage. There will be some debris in the transmission oil path but you can't clean there properly without splitting the cases. If all the debris was tiny it will probably make its way out eventually although some of it will embed itself into the bronze bushing in the transmission. Make sure to replace all o rings as you re assemble the cylinders and head. There are a total of 4 under both cam towers as well as the four that seal the cylinders to the block and head .Clean the rear center 2 oil passages in the cylinder assembly squeaky clean. Do the  same where these connect to the head. Debris here is the cause of cam bearing failure. 

[burlybear]

I had a similar incident with my 71 cb750.  Wore two holes in my tunnel and a whole bunch more damage.  I am glad you caught it before anything got worse. 

The only thing that I could settle on has the culprit is the PO rode this bike hard.  Lots of old race mods.  I guess under hard riding the chains would slap causing cracks in cases...

Post any results!

[wrenchmuch]

Looking over the pic of the debris again. There isn't much there. It be good to pull the oil pan and check there though. A cam chain shouldn't cause this kind of damage unless the tensioner/guides are worn or not functioning properly or the cam chain is so worn that the tensioner is at its adjustment limit and it still can't  take the slack out of the chain. The tensioner is easy to remove and it's gasket easy to make. It should be checked every few years. You can also put a small rod on the back of the tensioner and push the plunger in. You'll feel a little give with the adjustment bolt loosened. This lets you know the tensioner is working freely.

[ksteve]

Thanks everyone.

Check the clutch.

Yep, took the clutch out, examined, measured--looks almost brand new (did the Hondaman hole-drilling thing, while I had it out)

You should remove your oil tank and flush it out. Pull the oil pan and clean it. While the pans off remove the pump and replace the seals and o rings and check for proper pump rotor clearances as well as damage.

flushed tank and oil hoses, pulled pan, pulled oil pump and rebuilt it with new shaft seal, new big and little o-rings.

yeah id pull of all the little side covers. does your starter act funny? it could be something down that ally... change the filter too.

Pulled all side covers. Starter runs well. changed filter twice.

Looking over the pic of the debris again. There isn't much there.

Yeah, that's not a good pic. There was more than that. Here's a pic from after the first 100 miles:


I'm increasingly thinking I acted hastily in pulling the engine. I should have run it another 50-100 miles and it might have filtered out the rest of the aluminum after I adjusted the tensioner.
Oh, well, now i can have fun putting the top end back together. And I'll have the peace of mind knowing it's not the camshaft journals and that I have new tensioner rollers.