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View Full Version : Why you should maintain your swing-arm pivot bolt



Furyos J
20th July 2012, 08:10
Thought id do a bit of maintanance on the mrs trx400ex, and fix up the sloppy swing arm bearings. Pivot bolt was quite stuck.
Started out with the usual heat and hammer, didnt work. Next was heat and sledge hammer, still didnt work............ then realy wailing on it with the sledge........didnt budge. Next was heat and rattle gun on the bolt head.............thought it moved a little, but that was just the bolt head shearing off :brick:

Next was to cut the swing arm bolt, so i could get the motor out of the frame........ the cut between frame and swing arm was easy with a sabre saw, next cut was between motor casing and swing arm, but this required cutting the swingarm bearing inner collar, wrecked 4 dewalt steel cutting blades.......rersorted to using a carbide bit on a die grinder....... ok......motor is out now.

set up motor in my little 6 tonne press to press remains of bolt out of the engine casing, would not budge.........motor goes to local bike shop.....week and a half later he gives up on it as bolt has hardened due to my cutting with carbide bit and he cant even drill it out now.........

took it to Karl at cemeck engineering, 3/4 of an hour later...... your motor is ready mate.

took the chance to strip the frame back , repaint it, clean every part of the bike, new linkage, swing arm shock bearings. overhauled the 3 calipers and greased and checked everything else.

I will never forget to put copper coat anti sieze on a pivot bolt again!!!!!

Akzle
20th July 2012, 10:09
ode to 20 tonne porta-power press eh...
that's impressively fucked though. i hada CV joint/wheel hub/axle stub like that once... 10 tonne puller, 6 foot bar and slegde. ended up easier to take the gearbox out and pull it from the other side =S

Jay GTI
22nd July 2012, 20:40
The guy who bought my old RM (a mate) had similar issues when the swingarm bearings went on it. Which is why I pull apart my rear linkage, remove the swingarm and grease the crap out of everything every 10 hours or so.

gammaguy
22nd July 2012, 21:15
when I ran my own workshop and when later I worked at a franchise dealer,whenever a job came in that involved swingarm removal I would automatically add one hour labour to the quote,assuming that it would be rusted in from never being lubricated

I was seldom wrong...

scott411
22nd July 2012, 21:25
having had a kx125 into a 30 ton press to try and get one out, i know how hard it can be, they are a nightmare and a little grease from new and every 6 months or so, makes it much better,

gammaguy
22nd July 2012, 21:29
the four stroke engines that have a swingarm pivot thru the back of the cases are the worst,as the heat of the engine oil effectively boils all the grease out

I have seen brand new motorcycles with a tiny amount of grease on that would be lucky to last a few months.

Guess the manufacturers are happy to sell us a new pivot....

noobi
22nd July 2012, 22:41
Wonder if it is to do with the crappy seals which are used. I think O rings work much better.

Gasgas use O rings instead of lip seals. Greased the linkage and swingarm when I got it 150 hours ago, and it is still full of grease now. Was no swearing involved at all, was disappointed in a way. lol

IIIRII
23rd July 2012, 18:27
That may be true but I think you will find they wont be GasGAs "O" rings as I doubt GG make o rings ....
Actually , do any bike manufacturer's make "o" ring's or "Lip" seals ....

Probably just made up of bits .....


:)

barty5
23rd July 2012, 18:34
That may be true but I think you will find they wont be GasGAs "O" rings as I doubt GG make o rings ....
Actually , do any bike manufacturer's make "o" ring's or "Lip" seals ....

Probably just made up of bits .....


:)

you are right and in fact if someone wanted to im sure the is no reason you couldnt swap out seals and replace with rings as they come in many shapes and sizes

CRF119
23rd July 2012, 18:39
I had the same problem with one i rebuilt for a mate. After a few weeks of trying and soaking i made a jig up to safely place it in the 50 tonne press with out bending anything and that did the trick. Swing arm bolt was rooted.