L1 Swinging arm (1981)

[Ewetea]

I purchased the bike last June, and decided to check various items over the winter. First was the bearings in the swinging arm. Having removed the rear wheel and shock assembly, I cannot drive out the bolt securing the swinging arm to the frame. The exploded diagram for an L1 indicates that there is a sleeve internally, which I fear has rusted on the bolt, and is hard up against the ball bearing inner race. It does not seem possible to cut through the bolt between the arm and the frame to release the arm and then deal with the internals.I periodically smack the end of the bolt with a copper drift and heavy hammer, but since the frame and arm are alloy, I do not want to damage those parts by using too much force. I read all the problem pages and no-one seems to have experienced this problem before. Any ideas?

[masterofinsanity]

hi, firstly is it an L1 zxr400 as you state 1981? do you mean 1991?
not come across this before, have you tried applying a bit of heat to it? bit awkward to get to but it may help?

[zimm]

its possible that if its not been out since 1991 its seized in there .. I've had to scrap a bike before because of this (not a zxr.. a ts50x)..

it should just slip out

as you say, there isnt the clearance to cut it in situ unless you want to slice through the whole swingarm and replace it ?

heat may work, or it may make things tighter .. heat and cold applied alternately may be the trick ?

will the pivot bolt rotate freely once the nut is off ? if not I reckon a forceful attack with an impact driver on a cold day might be enough to work it free,, especially if you have an assistant twat the other end repeatedly at the same time.

[RedexRobB]

Since its hollow, what about a bit of ice cold water down the middle? If you dont mind replacing the nut, id turn that on a few screws and use that to make it a little easier to get to.

[cargo]

Bit of heat and some cold followed by more heat..................lots of liberal application of good pentrating oil WD 40 or something like it.............then






HIT IT

[jake]

ahh. ive got this problem with a spare h2 frame/swingarm. On mine the swingarm moves freely as it should, the retaining nut came off no probs.... but cant get the bolt and sleeve out. It sound like metal on metal when i hit it, not a dull seized kinda sound. I wish you the best of luck, i will be trying the above ideas too.

[lewisdale]

get a air chisel on it

[Ewetea]

Sorry lads. It should of course be 1991. I had another go at it last night. With the nut off the bolt turns freely by hand, but the graunching noise it makes indicates that not all is well inside. With all my efforts at hitting it, the bolt had emerged by 10mm. So I squirted WD40 everywhere, and used the nut to draw the bolt back. The nut came off and I hit the end of the bolt with the drift again, and then squirted more lubricant. That emerged a dirty brown colour, which speaks for itself. After half an hour of pushing and shoving, the bolt now emerges about 25mm. I'm concerned that all this brute force could be damaging the frame, so I am considering cutting off the head of the bolt, and using the thread at the other end, with suitable spacers, to draw the bolt out, thus applying controlled force. I have studied the exploded diagrams of the swing arm of both H and L models, and it would seem that a ball bearing was introduced to control side loading, needle rollers alone do not prevent sideways movement. So the bolt may be tight in the ball bearing, which is on the RHS. Thus drawing the bolt to the LHS could free it quickly. Oh, I only have a small blowtorch I use for plumbing jobs, and with all that aluminium the heat would have been dispersed to no effect. Thanks for the advice, and I'll post further info on what happens.

[Ewetea]

Right. The swinging arm is now out of the frame. I did what I suggested. The head of the bolt came off with a hacksaw relatively easy - I was expecting high tensile steel. The rest of the bolt was withdrawn using the thread to pull. Now that it is apart I understand the problem. The spacer in the middle is aluminium, with hardened steel caps pressed on either end to act as the inner race for the needle roller bearings. Thus the bolt was not rusted in the spacer. The problem was "dried-out" grease between the two. Since the spacer is 210mm long, and the bolt is 20mm diameter, that represents a very large surface area to resist movement. I simply wiped the crud off the outside of the bolt with a rag (without using any thinners), and then it slid easily through the spacer. It would seem that the dry grease is very resilient, so every time I hit the end of the bolt it "bounced". Also, the bolt is a snug sliding fit in the ball bearing, so attempts to push the bolt out resulted in build-up of the crud behind the inner race, inhibiting movement. By taking the head off and pulling the other way, it quickly became disengaged from the bearing. Also, by using the thread to pull, a steady and uniform pull was exerted which overcame the stickiness of the grease.
With regard to the owner of the frame and swinging arm with a similar problem, I would suggest lying the frame on its side with the threads of the bolt in the air to permit WD40 to be squirted on the bolt, which should then gradually seep through the tube and soften the grease. It may take a few days, and several applications of WD40, but it could help.That was not possible in my case because the rest of the bike was in situ.
Final observation: needle rollers are fine for small spaces, but in this application they only articulate slightly with the movement of the arm. That means that grease is not circulated, and each needle wears away at one spot on the sleeve. It was this action that wore through the case hardening of the sleeve and produced the brown liquid. I shall have a think to determine if a grease nipple can be introduced either side of the arm to permit regular lubrication - after all, there are grease nipples in the L-shaped arm supporting the shock absorber.

[masterofinsanity]

got a grease nipple in my swinger on my gixer, which reminds me i need to grease it.