Swingarm Pivot Bolt

Hey All

I'm down to just frame, motor and swingarm on a 98 wr400 and I cant seem to budge the swingarm pivot bolt to remove the motor. I'm sure this problem has arose in the past but any ideas on how to free this thing up. Have tried sledge, heat, lubrication........What the hell is holdin this thing in?

Thanks for any ideas

Probably rust and years worth of sludge. Unfortunately sometimes the only way to get it apart is to turn it over and cut it out using a sawzall. Have you tried using a press? Obviously not the easiest way, but it might work.


What the hell is holdin this thing in?

I strongly suspect its lack of maintenance (ie regular cleaning/greasing) and rust! An all-too-common occurance.

I'm not familiar with the 400s but I assume the bolt is hollow?

If so I reckon I'd track down some of that "Loctite Freeze and Release" spray.

I'd carefully heat the outside (ie the swingarm) first, being extra careful not to melt the aluminium. (Aluminium doesn't change colour when melting so be careful!)

I'd then spray the inside of the bolt with the Loctite spray.

I'd then go at it with a heavy hammer and (copper or similar soft metal) drift.

I reckon that would have to budge it, surely!


Edited by WR450FGreg

Ya it was most definatley neglegted. Looks like it had been sitting out in the elements for some time. I recently bought it as a parts bike (real short money) for my wr....same year and model....but it is all complete and I was thinking of trying a rebuild on it since I have a bunch of stock leftovers from my bike that would fit it.

Anyway, thanks for the suggestions. If I was to cut it, where would I do that? Does'nt seem to be any room between the swingarm and frame to get a blade in.

I'll try some of the solvent you suggested.....Maybe after it sits a couple days it might go.....When I grab the swingarm and move it up and down, the bolt actually spins with the arm. Do you think thats telling me its frozen to the arm itself and not to the frame or motor?

Never an easy job..........

Thanks a Lot for your help!

Frozen to the bushings. Those bolts are not cheap, so do what you can to save it. Heat, cold and deadblow hammers are your friend.

Edited by miweber929

PB Blaster. Lay the bike on it's side, soak from the nut side and spray in all the little gaps between the frame, arm, and motor. Let it soak for half a day and repeat. Then repeat again. I would absolutely NOT heat the swing arm. If you get it above about 250 F you will begin to alter the heat treat and could induce a really serious failure...the bolt is that big for a reason (the loads are high!). Get a big brass rod that is about the same diameter as the bolt, and bang on that sucker. If you leave the nut threaded on a couple of threads, you reduce the chance of dorking up the threads on the bolt (as miweber929 says, those bolts ain't cheap...)

When I was rebuilding my dads it 465 I had the same problem. I used knock'r loose and an air hammer:bonk:. But the bolt was already trashed from stripped threads so I wasn't to worried about saving it. Good Luck

I had this problem and what i did was just to spray WD-40 all around the little openings between frame and swingarm, and swingarm and engine. i DID use heat as well, but not too much. i also put super penetrant oil down the openings, and "worked" the bolt back and forth (i was able to move the bolt about an inch at first) to help distribute the WD-40 and super penetrant. lots of hammering and finally it budged. the two main ingredients to success are :thumbsup: hammering and :p anger, :mad: upon re-installation i cleaned it and then put synthetic grease all around it. hopefully that prevents it from happening again. GL. I know this bolt is a PITA!!! took me two days to get mine out...

also, here was my thread about it : http://www.thumpertalk.com/forum/showthread.php?t=932226&highlight=swingarm+pivot+bolt


Well, thanks for all the suggestions. It finally came out after a whole days work. Man, I dont even want to know if my good WR has the same problem....probably will since I have never lubed that pivot axel. Took a large cast iron window wieght and ground down the end till it fit in the frame hole, braced it up with some wood and straps and whaled the crap out of it with a 25lb sledge. That got it down flush with the frame....then whaled it back and then back again and was finally able to drive it through with a long steel rod. For anyone who finds this in a search for the same problem, I dont think heat will do anything since the swing arm bushings sit in a plastic sleeve......The problem is the metal bushings siezed to the axel and theres no way to heat those sleeves. The lubricant works only if you get the thing moving. There's no way for any lube to get into the frozen parts until she starts to move. Thanks to all who helped me with ideas. What a Nut Buster that was!!!

When I was rebuilding my dads it 465 I had the same problem. I used knock'r loose and an air hammer

Good idea if you can do it.

Trouble with the (later at least) WR450Fs is that the head of the axle bolt itself is actually round (with one flat face) and sitting inside a recess in the frame. All your work has to be done from the nut end!

Personally, I fully grease the swingarm bolt and both axles when I get any new bike these days. I re-grease them each time they come out too (unless I'm out in the bush fixing a flat.)

A mate of mine is having the same trouble with his '06 WR250F bolt. I warned him about greasing it not long after he first bought it. Did he listen? NO!

Now he's paying the price! LOL!


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