550 Catastrophic Clutch Failure - Do I need to do an engine rebuild?? Link to Pics!

Hi guys.

I was riding my XJ550 a few weeks ago when my clutch failed on a high RPM (9k ish, nothing ridiculous) upshift. I've only put about about 600 miles on it since my rebuild, and so I don't have a very long history with the bike. All required and neglected maintenance has been done in the course of my frame- off resto (oil, valve clearances, brake rebuild, carb rebuild+settings, forks etc). The only major maintenance items I haven't taken care of are new brake shoes (no signs of delamination and this was going to be my next buy for the bike) and new clutch.

I had heard of old clutches failing to grab or sticking and therefore needing a rebuild, and this was what I was waiting to happen. However, it did not happen in my case. The clutch did not fully engage upon the upshift and began making a loud grinding noise. The clutch lever had very little travel and did not affect the clutch very much. I managed to pull off the road slightly before the clutch jammed and the engine stopped, locking my rear wheel. With difficulty I kicked it into neutral and got it off the road where I picked it up in a truck and brought it home.

When I was draining the oil getting ready to examine the clutch I saw lots of small metal flakes in the runoff. A bad sign, but one I was expecting. Upon close inspection the clutch cover had a chunk of metal broken out next to the oil filler cap. After getting the clutch cover off I saw disaster- all but one of the outer clutch ring retaining brackets on the basket were broken off, all the attachment posts for the outer plate were sheared clean off, and the screws and springs were bent and broken.

So I know I need a used clutch cover, clutch assembly, new springs, screws, gasket, and friction disks (plain ones look good) to fix just the clutch.

My question is, what else do I have to do before running the engine again? And does anyone have an idea as to what caused the clutch to fail? I have included an album with photos of the damage and debris here:

http://imgur.com/a/tPX3A

Can anyone tell if those are the right screws or could it have been a PO using "hardware store" screws in the clutch causing this failure?

I can't imagine it is okay to leave all the little metal flakes to float around in the oil. I inspected the clutch area closely with a flashlight, and did not see any damage to anything else around that area in the engine. I do not think any big debris got into the engine, as it was all jammed up in a corner in the bottom if the clutch area.

Thanks for your help guys.

 

wow! glad you got to the side of the road safely! you will definitely need to flush as much of the metal particles out as you can. remove the drain plug, get a case of carb cleaner and go to town. a new oil filter is in order too.

CN

 

The good news is the pick up screen and oil filter should stop any pieces that would damage the engine. The bad news is if enough pieces end up on the pick up screen it could reduce oil flow.......

If you want to be 100% drop the pan and clean it out. Odds are though that most of the pieces are just inside the clutch cover.

I'm not sure I'd flush it with carb cleaner. Just new inexpensive oil. Wal Mart sells Accel brand 10W40SF for about $2.39/qt. that meets your needs (if you can find it). I'd do my first oil and filter changer pretty quick, like 100 miles or less.

 

Ha Ha Ha, i can laugh because it happened to me too

although it wasn't very funny at the time.
i strained the oil through a t-shirt, replaced the broken bits, put the same oil back in it and took it around the block and changed the oil and filter.
this time i tightened the bolts in the hub and used lock-tite

 

those bolts are the original ones but there's nothing special about them

 

Yep, happened on one of our bikes, too. Either a too loose or too tight clutch bolt(s) ---- too tight and you develop a weak pressure plate bolt post and then it comes apart and takes everything else with it ----- that 90-degree bolt sure held on for dear life, he wasn't the cause.

 

Holy crap. When I got my '83 550R, it had a bent clutch basket. Good thing I figured it out before it exploded.

Things to remember: the clutch housing drains DIRECTLY into the sump. Some seriously big pieces may have already gone down the 'ole.

I'm with Carl; don't flush it with carb cleaner. He's also right about dropping the sump and making sure, where we disagree is that I think there are probably some big hunks of shrapnel down there already... They won't get run through the motor, but I wouldn't leave them there either.

If you pull the exhaust system off, you can easily drop the sump (be careful of the oil level sending unit, they're fragile and not cheap) and clean it out. I would. You'll need a new gasket.

Check out my clutch article http://www.xjbikes.com/forums/index...-101-part-1-the-400-550-600s-with-pics.29541/ and put it back together. No rebuild required, not the end of the world. Just time for a little damage control and repair.

 

I've tried to drop the sump before, but I have a stripped screw down there that has prevented me from doing so...

 

I'd say shove a magnet down the drain cavity at the bottom of the clutch housing but most of the shrapnel is alloy and a magnet won't pick it up.

Now might be the time to fix that screw.

 

you can drill the head off the screw then remove what's left after removing the sump.

CN

 

Easily.

Or grab it with vice-grips. The sump bolts should all be the standard cheese-head hex socket cap screws.

A reverse-drill type screw extractor the right size to bite into the former Allen/hex socket usually does the trick. Or as above, just drill the head off.

 

Screw extractors have failed, so looks like I'll have to drill it off.

I sourced a donor clutch from eBay, can I reuse the screws or no?

 

i think your clutch bolts are shot
you can re-use your new ones. use a torque wrench and a dab of blue or purple loc-tite isn't a bad idea. sacked out springs will let the clutch slip just like worn plates and their cheap.

 

Had the clutch explosion happen to me last year. You need to pull the oil pan, there will definitely be chunks of clutch parts in there. check your oil pump screen for damage. Mine was OK, but might as well be sure.

 

Wow, clutch explosions are more common than I ever imagined.........

 

It's a sickening feeling. I thought, I just killed my bike! Then after calming down, I got to work fixing the Seca. Wish I had found this site back then. It took a long time to get the parts together and clean everything up. But, now I know Len's got everything I will need in the future and with drawing on the wisdom from members like Bigfitz52 and the other XJ Wizards, she will be running strong for years to come...

 

I had this happen on my FZR, that was down to pressure plate bolts too. Lessons learnt the hard way tend to stick!

 

I bow to your 9000 rpm I often attempt to redline my 750 but... the speed limit generally thwarts me.
Sorry not helpful...

 

Hi guys, thanks for all of your input! It makes me feel a lot better that this isn't a common problem, but that others have replaced shattered clutches without repeat failure. I know once I get back on the saddle I'm going to be paranoid about this happening again, but hopefully that'll go away with time.

I've got a quick update and a question (I'll post pictures once I finish everything up).

So I ground off the head of the stuck bolt on my sump, and removed it. There was less clutch material down in there than I expected, but I am definitely glad I took the time to clean it out. I cleaned up the mating surfaces and put a new gasket on before reinstalling.

I cleaned up the clutch area from the old flakes still left in there and installed a donor clutch after cleaning up the splines. I used a new lock washer as reccommended.

I'm now waiting for new bolts from Len (I'm reusing the old washers from my donor clutch but one was missing so I got a fifth from him too) to get everything put back together. I'll have a final (hopefully) update and pictures up soon, once I get done with everything.

My question:
A small piece of my engine case was broken when the clutch failed, around the area that I assume has to do with the crankcase breather. It was a small chunk at around 11 o'clock if you're looking directly at the clutch (picture attached). The "chamber" of this area doesnt seem to be connected to anything, although the breather hose opening is in a different chamber next to it (I believe right above). Will I be okay without doing anything about it? Also, let me know how the picture shows up for you guys, it's my first time posting an image on the new format.

Again, thank you all for your input and your thoughts.

 

A few more pictures (I know how much we all love them!):

The oil pan:



Notice the larger chunk on the center left. That's the piece of engine case that was broken off. It fits right back in the hole!



Old and new parts:



Parts replaced. The outer basket looks worn but in reality those areas are just polished- the surfaces are pretty smooth. I was going to run some finishing paper over those areas before reassembly but I was borrowing a buddy's 32mm socket so I had to get that bolt on there. I'll just have to do that on the bike now.



And a picture of my baby before this all happened. 1981 XJ550 Maxim restomod.

 

Holy Mother of all things fast! After 30+ years of drag racing, road racing and general tomfoolery I have to say I don't believe I've ever seen such epic clutch failures!