Hi, can anyone please tell me the thread size on the engine oil drain plug for a 2006 FXSTC 1580 ?

Thanks Bob.

 

Couldn't find FXSTC, but I'm pretty sure these are all about the same, at least from the same year for the Softail series.

https://www.jpcycles.com/product/601...ank-drain-plug

 

I believe your bike uses the Drain Plug # 60328-98B, which has 1/2 x 20 threads.....

 

Just did my first oil change in my "new to me" 2003 vrsca last night. The previous guy used locktite on both the drain plug and the filter. If the garage walls could blush, they would've been rosy from all the new cuss words. I was starting to "round over" the 17mm hex bolt when it finally gave way.

 

Agree.

 

Harley uses a 1/-20 thread special MS fitting o-ring seal. That o-ring seals in the bevel and not on the face. Any attempt to helicoli or insert repair is a pain. You no longer have a bevel.

As designed, Harley's plug goes metal to metal on the face and locks up. That fine thread is easy to strip with oil on it. It just needs a bump to stay tight. Torque to speck after a lot of oil changes will wear it out .

Interesting to see what you come up with. Harley should have an oversize self threading plug. Don't think so. AutoZone and Advance does but you will end up with a face gasket. That sucks except on the balanced engines.

 

I had to do that once as a young man on the first oil change on a brand new bike. One of those life lessons.