Rear axle wobble

Started by motorcycles, July 24, 2023, 08:47:28 AM

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motorcycles

Hi all,

I've got a 1999 M900 with a bit of strangeness going on with the rear axle.  After setting my chain slack this weekend, I noticed the rear axle has a bit of a rotational wobble. With both nuts torqued down there is no lateral play of the wheel, but the axle can spin a few millimeters forward or back before the chain adjuster plates stop it.  The nuts are not loosening, but rather moving together. It's as if the adjuster plates don't grip as they should and provide a platform for the axle to spin against the swingarm on.

Any ideas? My swingarm is recently swapped, so it's possible I have the wrong adjuster plates on there, but I did not think it would make much of a difference as I did not consider them structural.  Not currently riding it :/

koko64

#1
I'd like to see some pics of each swingarm. Was one steel and one alloy? I wonder if the axel or plates/adjusters are mismatched?  Torque is around 56 ft lbs iirc. What did you set the torque at? Using a good calibrated torque wrench? Do you have access to a manual? The nuts could be bottoming on the threads and not pinching the swingarm and plates. How much axel thread protrudes past the plates?  Is the wheel spacer fitted? Hub crush tube fitted?
Just some things to consider.
2015 Scrambler 800

motorcycles

Thanks koko,
I'll try get some pics and upload when I get a chance; I took the wheel off again and inspected everything (bearings, inner and outer spacers)-- all appears to be in good shape.  The new swingarm is a little slimmer, but it looked like it wasn't bottoming out on the threads.  I added some washers anyhow and took a hammer to the axle adjuster plates in my vice to bend them sung against the swingarm.  Tightening up those adjusters so they can't wobble seems to have helped more than anything. Tightened the axle nuts (I don't have a suitable torque wrench :/) and it seems to be ok for now. 

Took it for a spin and the clutch (dry) is slipping  [roll]

I got stuck having trouble shifting back to neutral and had to limp back home in 2nd through a long series of stop lights;
I took the plates out and they're well past tolerance (under 2mm! pretty sure the spec is a min of 2.8 ) . 
Steel basket and flat discs.
some slight ribbing on the basket, but I think she'll shift for another set of plates-- good god is it hard to find new clutch plates at a decent price. 

I'm losing the thread here, but I'll ask anyhow: Can anyone tell me if these parts are interchangeable? They seem to offer the same specs and the latter are easier to find:

Newfren F1335
https://www.newfren.com/en/Products/Clutches/F1335.html

Newfren F1545
https://www.newfren.com/en/Products/Clutches/F1545.html


koko64

The later packs have more plates for the high torque motors with a deeper drum.. Also check for steel vs alloy friction plates.
2015 Scrambler 800