1982 husqvarna 430 frame problem

[weimedog]

I have a 1982 Husky XC430 with a unique ability to spit off the nuts on the axle for the swing arm. Seems that when I ride it hard at out local MX track it literally starts shaking like its coming apart and when I get back to the truck those nuts are STRIPPED and falling off. Like the frame flexes and just tears off those nuts.

When I trail ride it or ride it on the fast hare scrambles type stuff this doesn't happen.

This has repeated itself three times now...so there is a trend. The bearings are tight in the swingarm, I THINK I have all the right Hardware for that axle / swingarm pivot in place....The bike looks straight. I'm stuck. Any Idea's?

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2001 VOR503 V-Cross
1982 husqvarna XC430
1974 Bultaco Frontera 360
6 Kids, Four Ride, 3 race. (cr125, yz80, 2 KX125's)
Case 780, INT 1066, Ford LTL9000...and a Percheron

 

[KTM/MAICO]

I'd start looking real closely at the axle and nut assembly. I never had any problems with any of my Huskys in that area including a number of 500cc monsters.

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[KTM/MAICO]

Oh, one more thing. In reading your post you seem to be referring to "two" nuts on the axle. Maybe you don't have an original axle as the nut on the left side (non chain side) is welded on. It also has a bent rod welded on in the same area that makes contact with the swingarm to help keep it in in place.

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[weimedog]

I don't have a problem with the Rear axle nut for the rear wheel. Its the pivot for the swing arm. The "Axle" for lack of a better word, that goes though the swing arm pivot and is the rear motor mount is the one thats just exploding off. Leaves a little "spring" behind..they used to be threads.

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2001 VOR503 V-Cross
1982 husqvarna XC430
1974 Bultaco Frontera 360
6 Kids, Four Ride, 3 race. (cr125, yz80, 2 KX125's)
Case 780, INT 1066, Ford LTL9000...and a Percheron

 

[DaddGoneMadd]

I don't have any help for you , but that is a cool bike. I sold my '78 390 OR seventeen years ago with the intention of buying a 430. But I bought a street bike instead, and it all went down hill...

 

[KTM/MAICO]

Weld the left one and safety wire the right one.

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[weimedog]

KTM/MAICO Think you have the right approach. Thanks for the concept. I think I will weld as you said and I think I will drill and roll pin the other side...I am just stumped on this one.

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2001 VOR503 V-Cross
1982 husqvarna XC430
1974 Bultaco Frontera 360
6 Kids, Four Ride, 3 race. (cr125, yz80, 2 KX125's)
Case 780, INT 1066, Ford LTL9000...and a Percheron

[This message has been edited by weimedog (edited 04-22-2001).]

 

[tentbound]

Make sure the swingarm bearings work properly. There should be one thin washer between the arm and the frame on each side. Tighten everything up with the shocks off and make sure the axle doesn't rotate when you move the arm up and down. This rotation of the axle will loosen the nuts every time.

The axle has fine pitch threads and if the nut gets a little loose, the side load on the axle will shear the threads off the nut.

I always thought that was a real cheesy way of mounting the swingarm to the frame. A lot of load gets transmitted to the cases. The KTM's from the late 70's had a great design. A tapped block on one side and a real strong pinch clamp for the axle on the other side.

Hope this helps,

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[SFO]

Man this stuff sounds super familiar.
I had a husky 610 that the swingarm pivot bolt was always coming loose.
It was like a 15 mm shaft with a 1.25 pitch thread on it?
The frame/ engine design seemed to heavily load this point.
The fastener was unable to sustain a torque.
I made a Ti pivot bolt with a coarse pitch thd that ended this discussion.

 

[weimedog]

I is a 15X1.25 thread. I had a freind who had a stainless one (why stainless???I don't know) made up at a machine shop with a coarser thread. I put it on and roll pined the right side and cotter pinned the left. Now I'm just crossing my fingers........Have a post-vintage race next weekend and I plan to ride the crap out of it this week to see if it holds together.

 

[weimedog]

Two HARD rides....and everything ELSE fell off. But the problem I posted has not repeated. ( Roll pined and cotter pinned seems to be working)