CLUTCH RATTLE OR OIL PUMP?

My 1984 XJ 600 (pre-diversion) had a very noisy what I thought was clutch rattle. Literally sounds like a bag of bolts in there! Although the clutch is on the right side it seems more noisy on the left side of the engine?
I have just removed the clutch and everything appears as it should be, I have replacement friction and drive plates as well as thrust bearing and will put all these in when I put it back together in the hope that something quiets it down.
But i'm not convinced now that the clutch is the real problem... The oil pump drive cog is very loose although securely held by a circlip. It has free play back and forth and also in and out... is this normal or could this be the cause of the noise? Or does anyone out there have any other ideas? I don't think its bottom end but maybe it could be camshaft/camchain rattle?? :?:

 

Well since you have an XJ and not an XV it really shouldn't ever sound like a 'bag of bolts.' If you don't have a stethoscope (very handy tool) you can use a short peice of PVC or other pipe and 'probe' the engine an oall sides to both pinpoint and isolate the sound. One year pressed against one end and slowly move around until you've narrowed it down. It could be number of things making the noise, does it change when you pull in the clutch, advance or go away with increasing revolutions? What maintenance have you done recently?

 

Thanks for the reply, I tried my ear on the end of a screwdriver! Not much luck, i'll try the pvc pipe. The bikes new to me, a cheap project...Ha Ha. Pulling in the clutch lever didn't really make too much difference I don't think, and increasing revs just made it harder to hear the noise!! I'm now beginning to wonder if it may be cam chain after all?? I'll put the new clutch in, (I've pretty much got a whole complete new clutch for it) and start again. I was just wondering about the loose oil pump cog before I reassemble it, any thoughts?

 

Primary chain/transmission rattle is common in the chain-driven XJs. The primary chain is a "true" primary chain, in that it drives the clutch/transmission (unlike in the shafties where it only runs the jackshaft.)

As such, it has an hydraulic chain tensioner that is operated by engine oil pressure. The degree of this rattle can be greatly diminished if you:

-Be sure you're running the correct oil; motorcycle spec 20W40 or 20W50.

-Get the idle smoothed out. The bike should idle at 1200 RPM and the smoother you can get it, the less primary/clutch/trans rattle you'll have.

A too-low or lumpy idle will make it rattle a lot more noticeably.

 

Thanks for input...
Have taken clutch apart again thinking it may be a loose dowel pin on the oil pump drive gear but all looks fine, infact the new dowel pin seams to be a slacker fit than the old one! Not sure which one to put back in??

Primary drive chain maybe?? Will take a look at my Haynes manual!

The main push rod is loose and could cause the rattle, but all the parts seam to be there, I thought of putting in and extra washer between the shoulder of the push rod and the thrust bearing to firm it up... is that a bad idea or not?? Would it cause friction and heat? I think this means that the end of the push rod would sit on the main nut... that can't be right can it?

Any thoughts anyone? Cheers

 

I gave you a whole bunch of thoughts, like 20W50 oil and smooth out the idle. My 550 at idle sounds like a sewing machine.

Also, be sure your clutch is put together properly. If it has the tabbed plain plates and "clutch boss spring" within a friction plate like the 550s do, it could have been reassembled incorrectly by a PO.

Worth a look anyway: http://xjbikes.com/Forums/viewtopic/t=29541.html

 

Correct oil, correct revs... an now convinced that primary chain is rattling, the thing is, could it be down to low oil pressure (dodgy oil pump) or the pressure to low to lift the chain tensioner enough or could it be the chain itself (stretched?)? When I bought this bike (recently) the oil filler cap has been cross threaded so doesn't screw down all the way, could this adversly affect the oil pressure enough to cause the rattle, have ordered a new cap, am waiting for it to arrive.

Am visiting a mechanic guru tomorrow who should be able to point me in the right direction... we'll see.

 

You can check your oil pump by starting on the center stand and observing your oil sight glass-if your pump is good the oil will basically disappear almost immediately as it heads up to ironically the head!

It should then take several minutes for the level to return after shut-down. BTW how many miles on your bike?

...and no, your filler cap won't have any appreciable effect at all.

Just to help you along, XJ's are notoriously noisy machines especially when compared with today's heavily jacketed water cooled high-reving motors. Also when I got the 550, it took two oil changes with QUALITY motorcylce oil to calm down, and by the third change it had a new 'quieter' lease on life. It should be mentioned though that the wet clutch is still fairly 'not quiet!'

 

Bike is sweet! Still a bit noisy in the primary chain... a job for later on, now have K & N pods running real good with a jet change kit, floats were WAY out of wack, now that they're set its going GREAT. Bought the most expensive oil I could get and the clutch is as smooth as. Thanks to all, nice learning curve, v happy with results so far...