leaking primary derby cover theory
Thread Starter
|
Tourer
Joined: Aug 2013
Posts: 260
Likes: 0
From: Phoenix, AZ
leaking primary derby cover theory
Before I get in to the details, the main question is whether or not you guys think it's time to replace the outer primary cover.
To begin, the previous owner dropped the bike on the left side once. There was a dent to the gas tank, scuffing on the shift pedal, a large scuff to the outer primary cover, and some slight scratches on the derby cover.
At one point I removed the derby cover to drain and replace the primary fluid. In my absolute stupidity I over-torqued the bolts mistaking inch-pounds for foot-pounds. I only had to ruin 2 bolts and my torx driver to realize I was doing something wrong. I inspected the derby cover and noticed I had warped it near the bolt holes and even cracked it slightly which I felt explained the new leak.
I went to HD and bought a new cover and gasket, went to Harbor Freight and got the smallest torque wrench (after reading the reviews of course) and replaced the cover. I am confident that even within the variation of the torque wrench, I am within specs for the derby cover BUT the leak is now worse.
My theory is that when the bike was dropped, the shape of the outer primary cover was compromised but so was the derby cover so the seal was maintained over all until I opened it. The new cover may not make 100% contact around the opening.
The other theory is that when I over tightened the bolts, in addition to damaging the derby cover, I could have damaged the outer primary cover as well but since they were damaged together they still maintained a decent seal.
For now, I have the new derby cover on the bike and I've put JB weld in the crack in the old derby cover. Once the JB weld cures I'll swap the derby covers out again and see if that helps. If not, I believe I'll have to replace the outer primary cover. An expensive lesson in paying attention to details.
To begin, the previous owner dropped the bike on the left side once. There was a dent to the gas tank, scuffing on the shift pedal, a large scuff to the outer primary cover, and some slight scratches on the derby cover.
At one point I removed the derby cover to drain and replace the primary fluid. In my absolute stupidity I over-torqued the bolts mistaking inch-pounds for foot-pounds. I only had to ruin 2 bolts and my torx driver to realize I was doing something wrong. I inspected the derby cover and noticed I had warped it near the bolt holes and even cracked it slightly which I felt explained the new leak.
I went to HD and bought a new cover and gasket, went to Harbor Freight and got the smallest torque wrench (after reading the reviews of course) and replaced the cover. I am confident that even within the variation of the torque wrench, I am within specs for the derby cover BUT the leak is now worse.
My theory is that when the bike was dropped, the shape of the outer primary cover was compromised but so was the derby cover so the seal was maintained over all until I opened it. The new cover may not make 100% contact around the opening.
The other theory is that when I over tightened the bolts, in addition to damaging the derby cover, I could have damaged the outer primary cover as well but since they were damaged together they still maintained a decent seal.
For now, I have the new derby cover on the bike and I've put JB weld in the crack in the old derby cover. Once the JB weld cures I'll swap the derby covers out again and see if that helps. If not, I believe I'll have to replace the outer primary cover. An expensive lesson in paying attention to details.
Both of your theories are sound. Outer Primary has got to go. The initial impact, more than likely, warped it slightly but not enough to cause significant leaking. Your tender hand added to the issue and now you have a cracked OPC. Get thee to eBay and get a new one!
Ultimate HDF Member
Joined: Apr 2008
Posts: 5,384
Likes: 12
From: Out on Deranged
the outer primary cover is made of die cast aluminum. it could crack but would not be likely to deform. come to think of it those parts are both aluminum. Check to make sure when you re-assembled the cover that all the oil from the exterior of the gasket on out was wiped clean.
You should show a picture of the primary open so we can see inside.
You should show a picture of the primary open so we can see inside.
Tourer
Joined: May 2013
Posts: 256
Likes: 2
From: The D
the outer primary cover is made of die cast aluminum. it could crack but would not be likely to deform. come to think of it those parts are both aluminum. Check to make sure when you re-assembled the cover that all the oil from the exterior of the gasket on out was wiped clean.
You should show a picture of the primary open so we can see inside.
You should show a picture of the primary open so we can see inside.
And when the initial incident happened, the probably both bent in together maintaining the seal...
I'm guessing you are right in your theories on this. Hopefully you don't have to get a new primary cover though....
*edit* Not to insult your intelligence or anything, but have you gotten a new gasket for the derby cover? The one that is in the bike from the factory is different than the one the dealer sells when you swap/replace derby covers....
Last edited by ShiftyCapone; Jun 14, 2014 at 03:23 PM.
Elite HDF Member
Joined: Jul 2007
Posts: 4,749
Likes: 16
From: sand mountain Alabama
I use a piece of glass to check to see if there is a bad spot when the derby covers goes. Just pull the derby cover. Take a small piece of glass that will fit over the derby hole. See if it rocks or any spaces when the glass touches the primary cover. This will show if it is warped or not and you can see if there is any small places oil could slip through.
I like the gaskets that has the orange ring around the mid part of the gasket.
In the 60's and 70's everyone used glass to shave the heads and fix warped heads. Glass will be perfectly flat.
I like the gaskets that has the orange ring around the mid part of the gasket.
In the 60's and 70's everyone used glass to shave the heads and fix warped heads. Glass will be perfectly flat.
Last edited by dirtdobber; Jun 14, 2014 at 04:38 PM.
Club Member
Joined: Dec 2007
Posts: 4,192
Likes: 168
From: Knoxville, Tn
Outer Primary
I have a scratch on the bottom of my chrome outer primary just like that from leaning the bike way over in a curve...I don't use a torque wrench when reinstalling my derby cover...All they need to be is firmly tight and you need to follow the sequence pattern in the maintenance manual. Gorilla torquing any bolt is a bad idea and if you don't firm them up enough on the first try, just put a little more pressure on them.
Ultimate HDF Member
Joined: Apr 2008
Posts: 5,384
Likes: 12
From: Out on Deranged
It appears as though it is slightly bent or dented in when you look at picture #2 from the OP. There is a little more edge showing from the derby cover. It's probably not sealing properly there....
And when the initial incident happened, the probably both bent in together maintaining the seal....
And when the initial incident happened, the probably both bent in together maintaining the seal....
Trending Topics
Road Master
Joined: Jun 2013
Posts: 1,181
Likes: 98
From: north of the south pole
Aluminum will bend. Even brittle cast aluminum will bend once. Just don't try to bend it back if ya don't wanna break it.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Thread Starter
|
Tourer
Joined: Aug 2013
Posts: 260
Likes: 0
From: Phoenix, AZ
arghghhhhhhhh, I did the swap like I said I would, here are pics of the OPC opening, doesn't look damaged to me but who knows. How about the new derby cover? Cracked at 3 holes. I am not happy- no wonder it was leaking so bad. Those bolts were torqued to 85 inch-pounds +/- 4% so they were definitely not over tight. Well the old cover with fresh JB weld is back on and the engine is running to get her nice and hot to see if she'll leak. I am going to attempt to return the new, broken derby cover to HD, I'll let you know how that goes....