Knock when taking off in first gear from the rear..XJ 650

Hi again all ye experts.
Morg65 again looking for advice..
I have an 82 XJ650..She only has 26000 miles up on her and is an original one lady owner from new. I know the girl who used to own her and she treated her like a kid.
I bought her a number of years back but have only done 300 miles since.
But I notice when pulling off at the lights I get a slight knock which appears to come from the shaft. I can feel it thru the seat. Happens again slightly in second gear then its gone. I recently had the shaft oil changed and there was no obvious sign of metal in the old oil. Some of the guys here in Dublin say that shafties ( as they call them ) make all sorts of noises and am wondering if this is a common thing on the old XJ.
Any advice would be great.. Once again thank you all for your help.
Regards,
Morgan..

 

Are you sure it's not clutch "shudder" ??
The final drive unit is very solidly engineered and rarely fail.

And have you looked at your rear brake shoes for delamination??

 

Thanks Wizard.
I dont think its clutch shudder..Wouldnt it happen through all the gears.?
It seems that its coming from the rear hub..When I let the clutch out in first gear I get the knock..But not everytime. I havent hit the brakes hard but they seem to work fine.
So you reckon the knock could be the maretial coming loose from the brake shoe and moving around in the drum.?

 

Re: Knock when taking off in first gear from the rear..XJ 65

does the 650 have the cush drive rubbers in the rear hub?
if so they would be my first point to look.
stu

 

His handle is TIMEtoRIDE, not wizard, that's just a status based on the number of posts, and yes, there is a member whose handle is "wizard."

I would think clutch shudder would be related to the difference in rotational speed of the wheel and engine, which is greatest when you are moving slowly.

If you haven't checked for brake delamination, don't wait for an explanation or troubleshoot, DO IT NOW. It doesn't matter how much it's been babied. My turbo seca sat for 20 years, had only 6k miles on it, and as soon as I pulled the rear brake hub, the WHOLE friction material on one of the shoes fell right off.

Check the wheel bearings too. 26k miles would be enough for either that or the clutch it they haven't been replaced. The u-joint also comes to mind, those I think you need to pull the swing-arm to check that.

Final Drive doesn't make any "regular" noises really. Just a question though, when you take off, do you drive through the whole rev range, or do you keep the RPMs low? Are you lugging the engine (not un-heard of from people used to bikes with more low end torque).

 

Heya,
I don believe the XJ650 has cush drive rubbers but am open to correction..
Thanks fot the advice..
While I am here can anyone tell me if the knocking noise I get thru the front end when I hit bumps or bad road surfaces is actually the floating calipers just knocking up and down. The stearing bearings have been checked and are fine..Guy who serviced her told me the knock was normal due to the floating calipers.

 

Re: Knock when taking off in first gear from the rear..XJ 65

we've been down this road before and nobody knows for sure but most think it's this. it's a shaft bikes equivalent of a cush drive just doing it's job.
sometimes you can feel it, if you start out real easy it doesn't happen.
doesn't seem to cause any problems, never heard of anyone fixing it.
probably that big spring getting old. consider it character

 

Are the steering head bearings tightened enough? If too loose, you can feel a knock, especially when coming to a stop after some smooth, hard braking.

The calipers shouldn't make any noise when hitting bumps.

Are the forks mounted properly? Pinch bolts torqued to spec? Axle? Proper spacer in the forks (preloading the springs)?

 

Thanks ManBot13. I see that now..Its good to have XJ wizards at hand.
Its given me food for thought.. But I will take TimetoRide's advice and check out the rear shoes.
Had her checked out last weekend and seems all the front end is tight. But especially when I go over speed bumps on the road I get this knock thru the forks I suppose..This guy was sure it was due to the movement of the as he called them "floating cailpers" He has a good rep over here where it comes to the older Yamaha's.

 

Hi Manbot13..
Can you explain to a First Gearer what you mean by lugging. I dont drive her thru the revs range and never go over 3 thousand even in 5th. I'm easy with her..
Sometimes if I am slowing down thru the gears I do get a sort of rattle but I put this down to being in too low a gear.. Is this lugging.?

 

Driving below 3000 rpm (obviously, when you are trying to get torque out of the engine, not when engine braking or putting no load on the bike) IS lugging the motor. It'll shudder a whole bunch when you do that.

These bikes don't produce much torque below 3000 rpm, and reach peak torque at 6000. If your bike is well tuned (and check that rear brake for delamination before riding it again), you aren't hurting it driving it right up to the redline.

 

After all these responses nobody said anything about the splines that drive the rear wheel, if these are dry that is most likely the place where your clunk is coming from. So pull the rear wheel, check the splines and the brake shoes.

 

Thanks to all of you for the advice.Before I changed the shaft oil there was a clicking noise when going up hills in first or taking off at the lights. Now this seems to be gone..
Now just a dull thump like clunk only in first and slightly in second.
I can feel it through my ass lol.
And as Polock suggested it doesn't happen at all if I take off easy.
Can I ask LVSteve2011 if there is any reason why the splines would be dry and if so would this not show up through all the gears.?

 

Hi Morg, The splines would only be dry if they were neglected for a long time. As for the second part, as you go into higher gears, especially how you drive, you would feel less and less of the clunking. but if you accelerate hard you would feel it in all gears. I think you mean "final drive case oil" as there is no oil bath for the shaft like a BMW. If the splines are not dry, it could be alot of other reasons for the clunking, such as loose drive shaft flange bolts, or a badly worn final drive, or worn splines on the ends of the drive shaft. The only way to tell is to take the rear wheel off and see what kind of wear you find. The job is not hard the final drive has 4 bolts and a shock to remove, and the shaft may pull right out, if you have the shaft without the clip on the "universal end".

 

Re: Knock when taking off in first gear from the rear..XJ 65

The brake caliper shouldn't be clunking. That design is tough enough to keep moving normally, and certainly not enough play to clunk. You might check around the headlamp and gauges for something loose too.

If you're shifting below 3K rpm there is going to be all kinds of noise because the engine will shudder and make every bit of play in the drive line knock around. The engine has a very short stroke and not much moving mass, it's made to turn lots of revs.

For going to church on Sunday you can shift at 4K, otherwise run it up to 6.

If you really want to enjoy the bike shift at 8500 - 9K.

 

I'm with polock on this one - just typical shaftie xj clunk, been down this road before a few times indeed.

no need to worry

 

Heres a thread I started last may describing what i believe the same issue you are having is:

http://www.xjbikes.com/Forums/viewtopic/p=325685.html

 

Guys,You are all fantastic for this.
So I understand from what I hear the the splines on the shaft need to be greased up or oiled manually.? And the drive oil only lubes the final drive.? One thing though..I am constantly messing with the clutch adjuster on the lever. Still trying to find the ideal position.. Maybe this has contributed to the clunk.?

 

Re: Knock when taking off in first gear from the rear..XJ 65

There is a splined drive hub (Yamaha calls it a "clutch hub" :?: ) bolted to the rear wheel. The hub slips into splines inside the final drive. Those splines should be kept lubricated with Moly grease. Something that should be lubed every time the wheel is off.

The splines where the drive shaft goes into the universal joint should also get moly grease. Not too much extra work to do if you have the rear wheel off anyhow.

What I'm not sure about is the end of the drive shaft that goes into the final drive. On their big (Venture, V-Max etc.) bikes Yamaha went to a design that lubricates those splines with the gear oil. Not sure if that made it into the XJs or not. Hopefully someone else knows for sure.

It's not uncommon for these splines to wear out on the big bikes. To my knowledge they don't give a noticeable clunk when going. They just strip and leave you at the side of the road.

 

Hi Carl, the big end splines just get moly grease, there is a groove cut into the coupling for it and that's why there is a seal on that end.

 

No offense morg65, but since you are pretty new to XJs (given your explanation of riding habits) it's important that you don't rule out that you are "mis-describing" the issue. I think it's best for us not to focus on the final drive exclusively.

Give that it's got 26000 miles on it, you should probably amalgamate all of these responses and check every single thing:

1. Pull the rear wheel, inspect and lube the splines, check the rear bearings, and consider replacing them.

2. Remove shocks and inspect swing arm play. Even if it seems fine, you'll be removing it shortly.

3. Inspect the u-joint as specified in the thread mtnbikecrazy55 linked to.

4. Remove the swing arm assembly and grease and inspect all splines.

5. Disassemble swing arm bearings, inspect, clean and lube them.

6. Replace the brake shoes, even if they aren't de-laminated.

7. Reassemble.

7. Also suspect your clutch to either be worn or out of adjustment. If you are having trouble finding the right adjustment (and are turning the adjustment screw in small increments) then it's likely your clutch is done. While there is a narrow range to set the clutch, it shouldn't be hard to find. If it hasn't been replaced ever, it's time. Things can "clunk" if the fingers of the clutch basket have grooves worn in use.

All of the above is regular maintenance for a 30 y/o motorcycle, especially one with 26000 miles. Your symptoms could be one thing, or several things that contribute to a "rear end clunk." Even if you still have the clunk, and it is normal or abnormal, the above should be done anyway, so it's best to do it and rule it out as a cause of your symptoms.

 

Re: Knock when taking off in first gear from the rear..XJ 65

I will say this about my XJ650 - when I put 20W50 oil in it I could never get the clutch adjustment where I was happy. I'd have to adjust it to where it didn't want to release cold or was inclined to slip hot.

I never opened it up, so it may have been excessively worn. With 10W40 though I was able to adjust it so it worked well at all temperatures.