Primary tensioner part # help
My research directed me to the Hayden tensioner.
Ironically, a buddy is also updating the primary on his at the same shop, & he also chose the Hayden tensioner.
The shop put his together and found the Hayden setup was extremely noisy and he reached out to me to let me know it might not be a good choice; his recommendation was to use the factory tensioner instead of an aftermarket version.
That being said, I started tracking down the part # for the factory tensioner & I dont know which version is correct because there is a ton of conflicting information.
Two different part #s appear to be correct depending on which site I look at
Ronnies online microfiche:
39929-06C
ShoputahHarley:
40063-05B
Can anyone help clarify the differences, etc.?
In about 2010, they went to an upgraded version of that tensioner #39929-06B as OEM. I was far less problematic than its predecessor. I used one in a high HP/TQ crate engine in my '16 bagger without issues.
There were significant changes between the "A" tensioner and the "B" tensioner that made it a better tensioner.
Then in '21 (IIRC) they upgraded it again to the #39929-06C tensioner. I have not seen a "C" tensioner and don't know if there were any changes made, or they just switched vendors... but I believe that is the current superseded part number for a primary tensioner now...
If you can get a NOS "B" tensioner (like on ebay) or get the "C" tensioner you should be fine...
In about 2010, they went to an upgraded version of that tensioner #39929-06B as OEM. I was far less problematic than its predecessor. I used one in a high HP/TQ crate engine in my '16 bagger without issues.
There were significant changes between the "A" tensioner and the "B" tensioner that made it a better tensioner.
Then in '21 (IIRC) they upgraded it again to the #39929-06C tensioner. I have not seen a "C" tensioner and don't know if there were any changes made, or they just switched vendors... but I believe that is the current superseded part number for a primary tensioner now...
If you can get a NOS "B" tensioner (like on ebay) or get the "C" tensioner you should be fine...
Any idea why 40063-05B is listed as the right part according to the Utah dealership website?
Revisions from A through to C make sense, but the other part # is what threw me a curveball.
It's possible the "C" version is for the M8 bikes.....???
I had the "B" version in two twin cams and it worked great.... It will work in your 2007....
I read on another forum a year or so ago, that they now have a version "C".... Prior to that I was unaware there was another change.
Usually when they just change the suffix letter on a part number, it is an improvement or just a vendor change.... However it is usually the same part with same fitment...
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It's possible the "C" version is for the M8 bikes.....???
I had the "B" version in two twin cams and it worked great.... It will work in your 2007....
I read on another forum a year or so ago, that they now have a version "C".... Prior to that I was unaware there was another change.
Usually when they just change the suffix letter on a part number, it is an improvement or just a vendor change.... However it is usually the same part with same fitment...
REF# 26:
36500075A
TENSIONER,PRI CHN,X
This part replaces 36500075.
The Best of Harley-Davidson for Lifelong Riders
With this in hand, Im finally getting closer to the starting line
Thanks, I was unaware of what is in the M8s.....









