Swing Arm Installation

[70MXer]

Hello POG , I'm installing my swing arm on my 76 MC5 250 and apparently need some tips from the group. I pulled the tube out inspected the bearings and cleaned.packed with grease, I then installed the tube in the swing arm and installed each adjusting nut so the tube was centered based on the threads in each adjusting nut. I tightened the nuts and back off the left nut about a quarter of a turn, I then installed the swing arm in the frame with the swing arm bolt and secured the pinch bolt.I was able to get the swing arm to pivot up and down without the adjusting nuts moving (which I read somewhere that was the objective) is that it?  I can't back the adjusting nuts off hardly at all without getting to much side to side play. Just checking to see if I'm missing something? Oh, I did back fill the tube with ATF fluid. Any feedback is always appreciated. Thank you

[454MRW]

I usually shoot for around .010" clearance between the side of the axle tube and frame once the rear engine mount bolt is torqued down before cinching the lock bolt down against the swingarm pivot bolt head. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Penton
1976 MC5 400
1978 KTM 78 GS6 250
L78-79 MX6 175-250 KTM's
1976-78 125-400 RM's
2007 CR125R Honda
1977 MC250 Maico
2017 KTM Freeride 250R

[Rocket]

Here are my thoughts on the swingarm set-up. I have the motor in the frame and tight, adjust the nuts on the swingarm bearing assembly so it is snug, not too tight.  Then tighten the swingarm bolt and the pinch bolt.  The swingarm bolt should be shouldered up against the bearing tube to lock it in place so it will not rotate with the movement of the swingarm.  Very important to grease the swingarm bolt so it can be removed in the future. This is just how I do it.
RCG

[70MXer]

Thanks all for the help. I think I now understand. The key is to first install my motor , then recheck my final swingarm adjustment. Thanks again, much appreciated!!

[Rocket]

One thing I forgot to mention is, leave the shocks off so you can move the swingarm to make sure you don't bind it up.  It should move freely once everything is tight.
RCG

[70MXer]

Got it, thanks again!

[454MRW]

I usually shoot for around .010" clearance between the side of the axle tube and frame once the rear engine mount bolt is torqued down before cinching the lock bolt down against the swingarm pivot bolt head. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Penton
1976 MC5 400
1978 KTM 78 GS6 250
L78-79 MX6 175-250 KTM's
1976-78 125-400 RM's
2007 CR125R Honda
1977 MC250 Maico
2017 KTM Freeride 250R

[Rocket]

Here are my thoughts on the swingarm set-up. I have the motor in the frame and tight, adjust the nuts on the swingarm bearing assembly so it is snug, not too tight.  Then tighten the swingarm bolt and the pinch bolt.  The swingarm bolt should be shouldered up against the bearing tube to lock it in place so it will not rotate with the movement of the swingarm.  Very important to grease the swingarm bolt so it can be removed in the future. This is just how I do it.
RCG

[70MXer]

Thanks all for the help. I think I now understand. The key is to first install my motor , then recheck my final swingarm adjustment. Thanks again, much appreciated!!

[Rocket]

One thing I forgot to mention is, leave the shocks off so you can move the swingarm to make sure you don't bind it up.  It should move freely once everything is tight.
RCG

[70MXer]

Got it, thanks again!