Generators and Motors
[Home] - [HELP] - [Forums] - [Articles] - [Photo Gallery] - [Groups] - [Chat] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] - [Tools]

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Motors General Discussion > Onan Generators
Forgot Password? Join Us!

Notices

Onan Generators Restoring, operating and maintaining vintage Onan generators.

Onan Generators

Onan 7.5 JB armature removal question


I am in the process of tearing down my Onan 7.5 JB with the bad block. About to remove the...

this thread has 6 replies and has been viewed 795 times

Reply
 
Thread Tools Display Modes
  #1  
Old 12-16-2011, 04:36 PM
Don Smith Don Smith is offline
Registered-III
 
Join Date: May 2006
Location: Placerville, California USA The Gold Country
Posts: 493
Thanks: 49
Thanked 51 Times in 50 Posts
Default Onan 7.5 JB armature removal question

I am in the process of tearing down my Onan 7.5 JB with the bad block. About to remove the armature from the crankshaft. Does the JB series have the same crankshaft taper that is used on most RV type Onan generators? What is the best way to break the armature free from the crankshaft. It is a Magnaciter type generator head. Thanks in advance and Merry Christmas to all. Don
Reply With Quote
Sponsored Links
  #2  
Old 12-16-2011, 05:42 PM
Billy J Shafer's Avatar
Billy J Shafer Billy J Shafer is offline
Subscriber
 
Join Date: Nov 2004
Location: Centerville, Texas
Posts: 10,373
Thanks: 4,529
Thanked 7,503 Times in 3,617 Posts
Default Re: Onan 7.5 JB armature removal question

Remove the center bolt. Then lay something under the rotor to catch it. So that you don't damage the windings. Then you can use a board on the shaft of the rotor. Hit it with a hammer,then rotate it and hit it again. It should drop off. Just make sure the board is not on the bearing or the windings. Also avoid hitting the slip rings.
Reply With Quote
The Following User Says Thank You to Billy J Shafer:
  #3  
Old 12-16-2011, 06:31 PM
Max Thompson Max Thompson is offline
Sponsor
 
Join Date: May 2009
Location: N.W. Missouri
Posts: 3,517
Thanks: 2,509
Thanked 3,077 Times in 1,700 Posts
Default Re: Onan 7.5 JB armature removal question

Billy makes it sound so easy, of course he has done it many times. I found I needed to repeat those steps several times & used a board & a BFH to smack the side of the rotor many times. As Billy said, be sure you support the rotor with blocks or a sling, because when it does come off, it may be all at once.
Reply With Quote
The Following User Says Thank You to Max Thompson:
  #4  
Old 12-16-2011, 06:36 PM
Don Smith Don Smith is offline
Registered-III
 
Join Date: May 2006
Location: Placerville, California USA The Gold Country
Posts: 493
Thanks: 49
Thanked 51 Times in 50 Posts
Default Re: Onan 7.5 JB armature removal question

Hi Billy Thanks for the email. I have the center bolt still in place but without the nut. That should keep it from slipping off completely. If my memory serves me correctly I should hit it around the main body of the armature. At a right angle to the shaft. Is this correct? Did not want to damage the shaft or slip rings. Thanks Don
Reply With Quote
  #5  
Old 12-16-2011, 06:44 PM
Billy J Shafer's Avatar
Billy J Shafer Billy J Shafer is offline
Subscriber
 
Join Date: Nov 2004
Location: Centerville, Texas
Posts: 10,373
Thanks: 4,529
Thanked 7,503 Times in 3,617 Posts
Default Re: Onan 7.5 JB armature removal question

Remove the stud from the center. I have seen them break from the weight of the stator. Hit the shaft you will not hurt it.
Reply With Quote
  #6  
Old 12-17-2011, 02:45 PM
Don Smith Don Smith is offline
Registered-III
 
Join Date: May 2006
Location: Placerville, California USA The Gold Country
Posts: 493
Thanks: 49
Thanked 51 Times in 50 Posts
Default Re: Onan 7.5 JB armature removal question

The armature popped off like a dream. Found that one must use a larger hammer to transfer enough energy to pop it loose. Flywheel removal next on the list. Thanks Billy and Max. Merry Christmas
Reply With Quote
  #7  
Old 12-17-2011, 02:57 PM
Billy J Shafer's Avatar
Billy J Shafer Billy J Shafer is offline
Subscriber
 
Join Date: Nov 2004
Location: Centerville, Texas
Posts: 10,373
Thanks: 4,529
Thanked 7,503 Times in 3,617 Posts
Default Re: Onan 7.5 JB armature removal question

Forgot to tell you. As our stackers from the UK say. You need a big Fooken Hammer.
Reply With Quote
The Following 2 Users Say Thank You to Billy J Shafer:
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
J mag armature removal Allan Wright Magnetos, Ignition Coils and Spark Plugs 4 10-14-2011 04:35 PM
Magneto Armature Removal Jordan Magnetos, Ignition Coils and Spark Plugs 5 04-27-2011 11:08 PM
Armature removal 7.5 A27 little river Kohler Generators 7 01-24-2009 05:02 PM
Low Tension Mag Armature Removal waterpowered Magnetos, Ignition Coils and Spark Plugs 1 04-07-2008 08:56 AM
5CCK Armature removal Mat Phelps Onan Generators 8 01-02-2007 12:52 AM


All times are GMT -4. The time now is 03:28 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark
A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2014 by Harry Matthews
P.O. Box 5612 - Sarasota, FL 34277