Hi Forum,

I would like to do an oil change. According to the service manual I just drain the oil from the oil tank and not the motor. I looked all over the motor bottom and canīt even find an oil drain plug at the motor. Is this normal? I have an all my former bikes had the oil drain plug located at the motor.

Looking forward to your replies.

 

Do you have a Harley Davidson Field Service Manual? If not you should get one, it will help you out with learning about your motorcycle, what procedures are required and location of specific parts to do the required maintenance.

 

I do have that. It just still makes me wonder.

 

I have to say, that I like how HD solved that. Seems like stripped oil drain plug threads are not existing at HD.

 

The newer engines have an oil pan and yes the threads can strip out or you can crack the oil pan if you over torque the bolt.

 

Delboy's Garage on YouTube has a 5 part series on Softail maintenance. Even if you DON'T do the full-purge oil change, it's worth a look. A true deep-dive...

 

Great, Delboyīs Garage is awesome. I just watched all videos. Seems like I have to do much more than just an engine oil change.
Question:
- What dimension has the Gearbox oil drain plug O-Ring?
- What dimension has the primary oil drain plug O-Ring?

In the video he is talking about blue hylomar. https://hylomar.com/en/universal-blue/
That stuff is not available for pick up. Would this stuff work too? https://www.autozone.com/sealants-gl...E&gclsrc=aw.ds


Here is the link to the videos for all other ones with the same question https://www.youtube.com/playlist?lis...6J95AUvBNMSXYv

 

I got Hylomar on Amazon

 

I don't have the manuals, or experience, with a 1991 Fat Boy...

I used to own and/or maintain my 1989 EVO Heritage, and a friend's 1997 EVO Springer... both softail models... and I kept the Service manuals and parts manuals...

PRIMARY
For both the '89 EVO softail and '97 EVO softail... it shows an HD primary plug part number 739 (or 739A). It is below the clutch inspection cover on the bottom of the outer primary case. It is a 1/8" NPT plug that takes a T-40 Torx. It is NOT a shouldered bolt with an o-ring, nor does it tighten up against the case... it's a pipe plug. There is no torque spec. The spec tells how far to tighten it so it protrudes below the surface of the cover... 0.16" - 0.18".... Since it's a pipe plug, you don't want to over tighten it, or you could damage (crack) the case...

TRANSMISSION
Both '89 and '97 EVOs again show the same drain plug for the trans as used in the primary, an HD plug part number 739 (or 739A). It is on the side of the trans, just below the clutch release cover, facing out to the side, not down... It should be tightened just like the primary plug.

Just FYI... the EVO FLTs and FXRs show a shouldered bolt trans drain plug, with nylon washer, (HD # 722) in the middle of the bottom of the transmission case... but the softails show the #739 (or 739A) pipe plug on the side of the trans case...

Hope that info helps....

PS- Those #739A pipe plugs are used on primary drains of my 2001 and 2003 Twin Cam bikes... When I change the primary oil, after removing the plugs, I clean the threads and the plug with a thread chaser... I put some Loctite 545 on the pipe plug for reassembly, and let it all set for about an hour (probably unnecessary) before adding the primary fluid. I've yet to have one leak after I service them...

 

There is no o ring for the transmission drain plug or primary drain plug, both plugs are tapered pipe plugs, heed the shop manual about tightening them.
No hylomar needed on a drain plug, just use teflon tape.