The Jack's Small Engines Forum - Join Our Online Community
Reply to post

Hot!Flywheel Key keeps shearing !

Author
jmf111361
Starting Member
  • Total Posts : 8
  • Scores: 0
  • Reward points: 0
  • Joined: 2017/07/14 15:42:13
  • Status: offline
2017/08/25 16:58:21 (permalink)
0

Flywheel Key keeps shearing !

I have a Craftsman LT 4000 18.5 hp Briggs & Stratton engine. What (besides hitting something with the blades) would make the key shear within minutes of replacing it ? I just changed the oil & filter, it crunch right up and within no time it shears the key !!!???  Any idea's ?? 

9 Replies Related Threads

    Mikel1
    Moderator
    • Total Posts : 938
    • Scores: 39
    • Reward points: 1
    • Joined: 2016/04/14 18:48:53
    • Location: Georgia
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2017/08/25 17:44:43 (permalink)
    0
    Are you properly torquing the flywheel?
    AVB
    Super Member
    • Total Posts : 729
    • Scores: 31
    • Reward points: 0
    • Joined: 2017/06/21 16:35:48
    • Location: Elora, TN
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2017/08/25 17:56:46 (permalink)
    0
    Need the model, type number and date code. Some Briggs have since been upgraded to steel keys and increase torque specs.
    jmf111361
    Starting Member
    • Total Posts : 8
    • Scores: 0
    • Reward points: 0
    • Joined: 2017/07/14 15:42:13
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2017/08/25 18:15:13 (permalink)
    0
    I'm not sure of the torque spec's but I had it pretty tight. When I took it back apart the main nut was not tight ! I was surprised ! Someone else today said something about me making a steel key. You think that would hurt anything ?
    jmf111361
    Starting Member
    • Total Posts : 8
    • Scores: 0
    • Reward points: 0
    • Joined: 2017/07/14 15:42:13
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2017/08/25 18:55:01 (permalink)
    0
    Thanks AVB.
    Model # 31P777
    Type  0348 E1
    Date  040225ZE
    AVB
    Super Member
    • Total Posts : 729
    • Scores: 31
    • Reward points: 0
    • Joined: 2017/06/21 16:35:48
    • Location: Elora, TN
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2017/08/25 21:20:54 (permalink)
    5 (1)
    Okay your engine was subject of APSI 82 Bulletin back in February 2012 about flywheel key shearing. Briggs redesign the crankshaft and flywheel on July 1, 2012. (ASPI 89). Your engine is a 2004.
     
    Order flywheel key PN 796335. This is a steel key. Also increase the flywheel nut or bolt to 110 ft-lbs old spec was 100 ft-lbs. Use a torque wrench to tighten; no guessing or the use of impact wrench (a NO-NO). If not done to spec flywheel and crankshaft damage can occur.
     
    Your automotive parts store should have loaner tools if you don't have a torque wrench or go to Harbor Freight they are on sale right now around $10.
    post edited by AVB - 2017/08/25 23:06:31
    jmf111361
    Starting Member
    • Total Posts : 8
    • Scores: 0
    • Reward points: 0
    • Joined: 2017/07/14 15:42:13
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2017/08/26 10:18:38 (permalink)
    0
    Thank You so Much AVB !!!
    Blackhawk36
    Starting Member
    • Total Posts : 7
    • Scores: 0
    • Reward points: 0
    • Joined: 2018/11/20 13:59:22
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2018/11/26 09:56:10 (permalink)
    0
    Did the steel key work?
    jmf111361
    Thank You so Much AVB !!!




    AVB
    Super Member
    • Total Posts : 729
    • Scores: 31
    • Reward points: 0
    • Joined: 2017/06/21 16:35:48
    • Location: Elora, TN
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2018/11/26 10:15:55 (permalink)
    0
    Should have since it been over an year since the last post.
     
    BTW this only applies to 280000, 310000, and 330000 prior to 07-01-2012 (date code 120701****). Briggs redesigned the flywheel and crankshaft and are using double length aluminum key on the new engines. Don't use the steel key on the newer engines.
    Blackhawk36
    Starting Member
    • Total Posts : 7
    • Scores: 0
    • Reward points: 0
    • Joined: 2018/11/20 13:59:22
    • Status: offline
    Re: Flywheel Key keeps shearing ! 2018/11/26 14:05:10 (permalink)
    0
    Thank you.  Mine is a 310000 series manufactured 03-31-2011.  I'll post what I find.
    AVB
    Should have since it been over an year since the last post.
     
    BTW this only applies to 280000, 310000, and 330000 prior to 07-01-2012 (date code 120701****). Briggs redesigned the flywheel and crankshaft and are using double length aluminum key on the new engines. Don't use the steel key on the newer engines.




    Jump to:
    Copyright © 1994 - 2016 Jacks Small Engine & Generator Service, LLC