Primary fluid change
The inner primary & cover are both Alum but the screws are Stainless & sometimes there is galvanic corrosion that sets up in the threads between the two. Yes its a good idea to loosen the derby screws first because they a history of being difficult on some bikes. Ive always sprayed WD40 on the derby cover screws & rarely have had an issue.
The Serv Man has a full list of all TQ values & a tightening pattern where needed. These values are from the people who designed the product so following their instructions is a good habit to have. Any DIY mechanic should have the required tools including TQ wrenches.
Plan ahead, read the Serv Man, have the proper tools, take your time & do it right.
The Serv Man has a full list of all TQ values & a tightening pattern where needed. These values are from the people who designed the product so following their instructions is a good habit to have. Any DIY mechanic should have the required tools including TQ wrenches.
Plan ahead, read the Serv Man, have the proper tools, take your time & do it right.
Seasoned HDF Member
Joined: Jan 2007
Posts: 20,616
Likes: 4,440
From: anacoco, la
I would also add, before you start the bike to warm up the fluids (you do drain it warm, right?) go ahead and do the clutch adjustment. I would do a clutch adjustment/fluid change every 5k and the bike always felt like a new ride after that.
Grand HDF Member
Joined: Mar 2007
Posts: 4,928
Likes: 285
From: Edmond Oklahoma
I prefer torx over the Allen head. If using the correct size bit, it should not strip out. Also,I believe the advice not to torque your screws is bad advice. Screws & bolts are engineered to be torqued to a specific spec. If you go by the HD Service Manual specs,& use a quality torque wrench(preferably certified).I believe,by experience,you won't have any problems. Also, if initially torqued correctly, there is no reason for a re torque unless specified by the manual.
Just my .02
Just my .02
Beary
Road Captain
Joined: Sep 2011
Posts: 699
Likes: 13
From: Northeast
Just did mine this morning. A 2x4 under the jiffy stand and 38oz in the primary works perfect. You can't go wrong following the manual. As others have said make sure you use the T27 torx bit and not a T25 and the cover screws will be fine. I've always torqued screws and drain plugs to spec and have never had an issue.
There is a ferrous insert in the case, 5 of them to be exact, that the torx screws thread into, eliminating the galvanic corrosion issue.
When you take the derby off, look... it is quite easy to spot if you have it.
If I have to go pull my derby to take a picture for you, I will... just say the word.
I use a small 1/4 drive ratchet and extensions, and barely put out on the screws while tightening.
There is no pressure behind the derby, you only have to make the gasket seal against splash.
Novice
Joined: Jul 2015
Posts: 16
Likes: 0
From: North East OK.
I prefer torx over the Allen head. If using the correct size bit, it should not strip out. Also,I believe the advice not to torque your screws is bad advice. Screws & bolts are engineered to be torqued to a specific spec. If you go by the HD Service Manual specs,& use a quality torque wrench(preferably certified).I believe,by experience,you won't have any problems. Also, if initially torqued correctly, there is no reason for a re torque unless specified by the manual.
Just my .02
Just my .02
Good post, however the low end torque (I beleive 12 ft/lbs) has been known to strip out the aluminum oil pan. Trust me I know, and so does my mechanic (about $110 plus labor on my 09 SG). I don't know if this comes down from MOCO, but a lot of the mechanics are applying plumbers paste (as per manual) on the bolts and then just hand tightening them snug. I think using the small wrench here is good advice.
Beary
Beary
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Grand HDF Member
Joined: Mar 2007
Posts: 4,928
Likes: 285
From: Edmond Oklahoma
Not sure if you're talking about the primary inspection cover(Derby cover). The derby cover torque spec is 7-9 ft. lbs, or 84-108 in. lbs. That's the same for my Evo & 103. If these screws are being torqued to 12 ft. lbs., it's way too much. Just one ft. lb. of extra torque on such a small screw makes a huge difference.
Beary
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