Author Topic: Swing Arm Reinstall  (Read 1093 times)

0 Members and 1 Guest are viewing this topic.

Offline cb

  • Enthusiast
  • **
  • Posts: 124
Swing Arm Reinstall
« on: November 07, 2019, 08:19:43 AM »
I removed the swing arm to blast and repaint the frame and components. 
Now I cannot fit the swing arm back in.  It seems to be too tight by about 3mm. 
Am I going to have to pry it apart somehow?

Offline calj737

  • Really Old Timer ...
  • *******
  • Posts: 21,057
  • I refuse...
Re: Swing Arm Reinstall
« Reply #1 on: November 07, 2019, 08:34:13 AM »
Loosen lower motor mount bolts. That area of the frame is under tension. Tighten swing arm pivot until the arm falls smoothly and fully. Recheck after tightening frame/motor bolt.
'74 550 Build http://forums.sohc4.net/index.php?topic=126401.0
'73 500 Build http://forums.sohc4.net/index.php?topic=132935.0

"Of all tyrannies, a tyranny sincerely exercised for the good of it's victim may be the most oppressive. It may be better to live under robber barons than under omnipotent moral busybodies. The robber baron's cruelty may sometimes sleep, his cupidity may at some point be satiated, but those who torment us for our own good will torment us without end for they do so with the approval of their own conscience." - C.S. Lewis

Offline maxheadflow

  • Hot Shot
  • ***
  • Posts: 579
Re: Swing Arm Reinstall
« Reply #2 on: November 07, 2019, 08:52:01 AM »
I would loosen the top rear also.  You might want to mill file off the paint of the frame where the swingarm fits.  Also don't forget to make sure the ground cable make good contact to the frame and don't forget to check the motor mount bolts after some miles.

Offline bryanj

  • Really Old Timer ...
  • *******
  • Posts: 14,045
  • CB500 Number 1000036
Re: Swing Arm Reinstall
« Reply #3 on: November 07, 2019, 09:20:10 AM »
Remove the paint from the tube ends of the arms and from the inside of the frame where the swingarm pivots, especialy if its powder coat
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline cb

  • Enthusiast
  • **
  • Posts: 124
Re: Swing Arm Reinstall
« Reply #4 on: November 07, 2019, 09:40:04 AM »
I am just beginning to rebuild, so the frame is empty.  I am starting with the swing arm.
Filing paint off is a good idea, but it won't give me 3mm.
Do I dare pry some more clearance, or even use a scissors jack?

Offline Airborne 82nd

  • Expert
  • ****
  • Posts: 828
Re: Swing Arm Reinstall
« Reply #5 on: November 07, 2019, 10:20:05 AM »
Did you have trouble taking it off? If not then what other than paint changed?

Offline cb

  • Enthusiast
  • **
  • Posts: 124
Re: Swing Arm Reinstall
« Reply #6 on: November 07, 2019, 11:27:32 AM »
I don't recall having any difficulty.  I am using new dust washers and felt.

Offline jakec

  • Master
  • *****
  • Posts: 2,077
Re: Swing Arm Reinstall
« Reply #7 on: November 07, 2019, 12:09:20 PM »
That's really odd, when I installed my swingarm in my frame there was a lot of space and tightening the axle nut brought the frame together. Only a few mm, but still.
1970 CB750 K0
1977 CB750 Chop
1997 XR650L

Offline cb

  • Enthusiast
  • **
  • Posts: 124
Re: Swing Arm Reinstall
« Reply #8 on: November 07, 2019, 01:29:32 PM »
Perhaps I am placing the plastic washer and felt in the wrong place; I am trying to place them inside the swing arm, is that correct?

Offline bryanj

  • Really Old Timer ...
  • *******
  • Posts: 14,045
  • CB500 Number 1000036
Re: Swing Arm Reinstall
« Reply #9 on: November 07, 2019, 01:30:42 PM »
Have you replaced the bushes?
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline trigger

  • Enthusiast
  • **
  • Posts: 207
  • Engines built on reputation, not advertising.
Re: Swing Arm Reinstall
« Reply #10 on: November 07, 2019, 03:36:47 PM »
I don't recall having any difficulty.  I am using new dust washers and felt.

Do the new dust caps have rubber inside ? Or are they like the plain ones that you took off ?

Offline BenelliSEI

  • Really Old Timer ...
  • *******
  • Posts: 10,006
  • 1969 cb750
Re: Swing Arm Reinstall
« Reply #11 on: November 07, 2019, 05:27:48 PM »
Did you paint or powder coat the frame and swing arm? Years ago, I had a frame powder coated and I was convinced the heat tightened up the back! Just like you, swing arm would not fit. I gave it a tiny spread with the scissors jack and some 2 X 4’s. No problem, all good.......
« Last Edit: November 08, 2019, 05:13:48 AM by BenelliSEI »

Offline cb

  • Enthusiast
  • **
  • Posts: 124
Re: Swing Arm Reinstall
« Reply #12 on: November 09, 2019, 10:22:24 AM »
No powder coat, no new bushings; I have resorted to a bottle jack to act as spreader.  No other way to do it as far as I could see.
Many thanks to everyone who offered suggestions. 

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Swing Arm Reinstall
« Reply #13 on: November 09, 2019, 11:25:47 AM »
Something sounds wrong.  I would compare end caps, you might have changed to thicker ones.
 If you jacked your frame apart,  how can the  swingarm pivot freely ? And how can the motor mount bosses now clamp the engine in tightly ?
 I would be taking another look.,
« Last Edit: November 09, 2019, 09:03:10 PM by 754 »
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Airborne 82nd

  • Expert
  • ****
  • Posts: 828
Re: Swing Arm Reinstall
« Reply #14 on: November 09, 2019, 08:56:16 PM »
Something sounds wrong.  I would compare end caps, you might have changed to thicker ones.
 If you naked your frame how can the  swingarm pivot freely ? And how can the motor mount bosses now clamp the engine in tightly ?
 I would be taking another look.,
@ 754 what do you mean (naked the frame)

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Swing Arm Reinstall
« Reply #15 on: November 09, 2019, 09:03:45 PM »
 I meant jacked tge frame open.
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way