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Subject: Belt Adjusting Arm (Part # 8N-10145)

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Jim    Posted 06-27-2020 at 10:01:44 [URL] [DELETE]        [Reply] [Email]  
  • Belt Adjusting Arm (Part # 8N-10145)
  • For a 1949 8N (Serial 214385), the subject part is a short bar with two bolt holes, and I believe it is used to adjust the tension of the generator (6v) belt. One end I think attaches to the generator support bracket (Part # 8N-10151-A) but to what does the other end attach?


    Tim Daley(MI)    Posted 06-28-2020 at 05:23:17 [URL] [DELETE]        [Reply] [Email]  
  • Re: Belt Adjusting Arm (Part # 8N-10145)
  • HiYa Jim-
    The 8N-10145 generator Tensioning Arm bolts to the governor and the generator support bracket. I have a dozen or so OEM arms if you need one. This is used on the early 8N's with front mount distributor only. Fan Belt tension is vital to charging the generator/electrical system/battery -without tension you are flogging a dead horse. The side mount dist introduction revamped the gen and moved it to the LH side of engine and it had its own tensioning bracket.

    8N-10000-A GENERATOR w/ 8N-10145 TENSIONING ARM:


    *Used only on early 8N generator with the front mount distributor.

    Jim Lovejoy    Posted 06-28-2020 at 09:17:26 [URL] [DELETE]        [Reply] [Email]  
  • Re: Belt Adjusting Arm (Part # 8N-10145)
  • Thanks Tim for your speedy response with pictures and the generous offer of the OEM arm. When the tractor was purchased, it was in a serious state of disrepair. In this case, the arm was attached to the generator support bracket as pictured by your black generator and the arm's other end was not aligned with any bolt but lodged against the governor housing. The arm I have measures 3/16" thick, 3/4" wide, 2.75" long and with bolt holes spaced at 2" center to center. If this is not the OEM arm, then "yes" I'd like to get one from you.

    About mounting the arm. 1) Presently, the arm is not long enough to attach to a governor housing bolt. 2) The only governor bolt that might accommodate the arm is 1 & 5/16" long. 3) The head of this governor housing bolt screws in from the radiator side of the housing and just 2 to 3 threads exit from the carburetor side and there is no nut. 4) The belt is 46.5" long.

    I could likely overcome 1) if the belt was shortened so what are the correct dimensions for the belt please? (Manuals I have read just say "V belt.") 2) What is the correct length of the OEM governor bolt that should be used to attach the arm? I'll presume it must account for a nut and washer in addition to the thickness of the arm.) 3) Should that governor bolt screw in from the radiator side or from the carburetor side? 4) I'm concerned that the arm will ultimately damage the threads of the governor bolt and later the governor housing itself will become damaged when that bolt with bunged-up threads is later removed.


    Tim Daley(MI)    Posted 06-28-2020 at 12:25:16 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Belt Adjusting Arm (Part # 8N-10145)
  • Your arm is correct -I have the OEM drawing. Your belt is too long. Requires p/n 9N-8620-B. Someone sold you the longer belt used on the LH mount genny. Arm will mount above the governor -see pix. Bolt is 3/8-16 a 1-3/16" long. If not OEM try an 1-1/4.


    Tim Daley(MI)

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