Help!! Seized Swingarm Bolt

So I'm in the process of a full restore on my 83 550 seca. About a year and a half ago I changed out the chain, and in the process lubed my swing arm. At that time all I had to do was undo the nut, tap it with a rubber mallet, and it pulled right out. Now it is totally seized. If I move the swingarm up and down the bolt rotates with it. I have tried heat, pb blaster, an impact driver, a 3 pound sledge hammer, wd40, and holding the left side with an adjustable wrench and rotating the bolt left and right a few degrees. Nothing is working! Now I have a nut that is a bit messed up from the hammer, and a bolt that has been mushroomed over. At this point if it was loose I would have to cut off half of the exposed threads just to get it to come out.
Help! Any ideas would be great, I've already decided that I need to buy a new bolt. Torch cutting is Not an option.
My next move is to drill a hole in the right side and continue hammering using the hole and a drift pin and a bigger hammer. But as things have gone so far, I don't think this will help either.
Help!!

 

I'd slice through the Nut with a DREMEL Tool with a Cut-off Wafer Disc.

Make a "Bias Cut" through one of the Hex Flats, ... then, SPLIT the Nut with a Chisel.

You'll save a whole lot of aggravation and unnecessary applications of solvents and heat.

All you'll need to do is make a small cut.
Split the Nut.
Get the work done.
Replace the Nut with a New one or a good used one.

The job will go easy with the Flex Wand attachment to let you work in a tight place.

 

Sorry for the confusion. The bolt is the part that is seized, the nut is off and in 80% usable condition (just a few hammer marks on it).

 

if the bolt moves with the swingarm the bearings are seized, rotating the bolt won't do any good, all that would do is break the bearings free
what you have is the inner races frozen to the bolt.
get some Kroil or 50/50 ATF and lacquer thinner and get it between the frame and swingarm. then make sure the bolt threads will fit through the bearing inner race then drill a little indent in the bolt and pound, but you need to brace the frame so it doesn't move when you hit it, the best way would be to lay the bike down and support the frame right by the pivot.
just be careful you don't bend the frame

 

KROIL. Works when nothing else does, honest: http://www.kanolabs.com/google/


I don't see "adjusted valves" on your list of things that you've completed...

 

If worse comes to worst, is there enough slack in the swing arm that you could get a hacksaw blade or sawzall blade in there to cut the bolt? If you're gonna have to replace it anyway, cut it out, clean everything well, and there's plenty of parts available here in the forums.

Dave Fox

 

You got me there, I'm having someone else look at the engine. Also I haven't updated my signature in a while. With all the stuff I've done, it would take up most of the page.

I'll try the kroil, and yes worst case, a hacksaw.

 

Since you're going to end up replacing the pivot bolt anyway, why not talk to chacal about a roller-bearing upgrade kit and get rid of those sloppy stock bushings?

I plan on doing it myself as soon as I have to pull the swingarm for any reason.

 

Fitz, I read with interest your recommendation to switch to roller bearings from bushings for the swing arm. On my LT the wisdom is to switch FROM tapered roller bearings TO bushings ($130/pair for after market bushings vs $90/pr for the stock bearings). The rollers become "notchy" after a very short period of time. They do get notchy but once the pre-load is set the adjustment pretty much stays in place. The bushings have to be adjusted at intervals X 3 to insure the pre-load is correct.

I would think the rollers would be better but is this possibly a case of "what we don't have now" is better?

Either way a good heavy coating of never-seize applied to the bolt at assembly time should eliminate the fun at time of next dis-assembly.

Edit: I just had a thought come to mind (hey!, it happens!) on how to push the bolt out. Cut off the mushroomed out end of the bolt and use a pneumatic chisel with the sharp part of the blade part cut off to drive the bolt out. It's odd that the bolt mushroomed out considering that it should be VERY hard because of the stress it has to endure.

Loren

 

I have this feeling that the BMW swingarm bushings/bearings and related hardware are light years advanced from the primitive nylon bushings that were OE in the 550 Secas.

Haven't heard anything negative about the upgrade (other than the price.)

 

Careful about the light years ahead thing!!!!!! The bushings are oil impregnated bronze bushings so maybe a leeeetle ahead of the nylon bushings but not by much......

Loren

 

That Swing pivots on a "King Pin" Style Rod Bushing that pivots within "Opposing" Shouldered Bearing Bushing.

You hope to find the Opposing Bearing Bushings worn without damage to the King Pin's Outside Diameters.

Usually, the Bearing Bushings are made to wear-out without damaging the King Pin.

Hammer-on a Tight Fitting 6-Point Impact Socket and hit it with an Air Gun.

Cut a BIAS slice through the NUT and Split it of there.
The Bolt is a GUIDE BOLT that keeps the King Pin "Centered".

Hacking it off will mean replacing:
Bolt
King Pin
Bearing Bush
Possibly damaging the frame.

(A Diamond-Tipped DREMEL Bit that will let you "Grind" a path through that Acorn Nut is $17.00 -- A Vial of Cut-off Wafers is $12.00)