leaking from primary
Club Member
Joined: Jun 2007
Posts: 3,193
Likes: 7
From: North Atlanta Area, GA
I used to run AMSoil MCV 20W-50 in the engine, tranny, and primary - but I had a hard time finding neutral with the MCV in the primary. I switched out to Mobil 1 Syn ATF in the primary, and it's much easier to find neutral now.
I also switched to Mobil 1 LS 75W-140 Syn Gear Lube in the tranny, and it really smoothed out the shifting clunk.
Cruiser
Joined: Dec 2008
Posts: 234
Likes: 4
From: Courtenay, BC, Canada
It may not be your drain plug at all. I have this same problem on Bertha - until I discovered that it wasn't the primary drain plug, but one of the seals on the inner primary - tranny seal, shifter shaft seal, etc. One or more of them is leaking, and the primary fluid drips down the outside of the inner primary, and drips all the way down to the drain plug... so it looks like the drain plug is leaking, but it's not!
I know this because I've stuck a rag up as far as I can on the outside of the inner primary, and it's always wet on the outside. I haven't gotten around to fixing these primary leak(s), because I haven't gotten sufficiently motivated to pull the inner primary and all that that involves yet... I will this winter when there's no riding to do!
I know this because I've stuck a rag up as far as I can on the outside of the inner primary, and it's always wet on the outside. I haven't gotten around to fixing these primary leak(s), because I haven't gotten sufficiently motivated to pull the inner primary and all that that involves yet... I will this winter when there's no riding to do!
Club Member
Joined: Jun 2007
Posts: 3,193
Likes: 7
From: North Atlanta Area, GA
Thanks for the reply. It's ATF so definately comin from the primary. Could be a seal at the jackshaft or mainshaft, but I reached up under there after a ride and it was dry. I'm starting to get this sickening feeling that I have a cracked primary. I'll check it out this winter. Might be a good time to switch to a later model clutch, oh and 6 speed tranny, oh and a 124 Ultima! Well I can dream can't I?
Dream all you like! I dream about the new S&S V111 Touring engine they just came out with. Built for lots of low-end torque on heavy bikes... it would be perfect for Bertha, and for some reason it's far lower in price than their other engines... $5395 list in wrinkle black with IST ignition and a 3-year warranty. Sounds almost too good to be true for an S&S engine...
Advanced
Joined: Aug 2007
Posts: 63
Likes: 0
From: Northeastern Indiana
My drain plug leaks too. I've tried teflon tape, pipe sealant , gasket silicone and still no luck. I even bought a new drain plug (wasted my money). I changed out all the gaskets and I'm pretty sure it's the drain plug. I use ATF in the primary, RP in the trans and Mobil1 in the engine so I know it's coming from the primary. This is really pissin me off. Any ideas?
Cruiser
Joined: Dec 2008
Posts: 234
Likes: 4
From: Courtenay, BC, Canada
Yikes! That doesn't sound good...
Dream all you like! I dream about the new S&S V111 Touring engine they just came out with. Built for lots of low-end torque on heavy bikes... it would be perfect for Bertha, and for some reason it's far lower in price than their other engines... $5395 list in wrinkle black with IST ignition and a 3-year warranty. Sounds almost too good to be true for an S&S engine...
Dream all you like! I dream about the new S&S V111 Touring engine they just came out with. Built for lots of low-end torque on heavy bikes... it would be perfect for Bertha, and for some reason it's far lower in price than their other engines... $5395 list in wrinkle black with IST ignition and a 3-year warranty. Sounds almost too good to be true for an S&S engine...
Cruiser
Joined: Dec 2008
Posts: 234
Likes: 4
From: Courtenay, BC, Canada
My '96 Electra Glide had a primary drain plug leak also and like you I found the new plug wasn't any better. I removed the primary cover and redrilled and tapped the drain hole to 7/16 fine thread. Picked up a stainless socket head cap screw from McMaster Carr, used some teflon tape on the threads and put an o-ring under the head, no more leak. The 7/16 head just fits in the recess area on the primary cover, and the thread size isn't a whole lot larger than the pipe thread already there. Just make sure you cut the new bolt off so it doesn't make contact with the clutch basket/ring gear inside.
Cruiser
Joined: May 2010
Posts: 139
Likes: 0
From: Ann Arbor, MI
Deja Vu all over again. I had the same thing happen recently with my '97 fatboy. Thought it was shock oil, since it appeared to be dripping from the left shock (softail). Ruled that out and then assumed it was engine oil overflow (had just changed oil). Nope. Next, assumed it was gas--but the finger swipe test showed it was oil. Bingo, $400 and a new primary inner seal later and all is well. You don't fix that on the side of the road ;-) Overalll a fabulous bike, but hey, s**t breaks, ya' know?
Club Member
Joined: Jun 2007
Posts: 3,193
Likes: 7
From: North Atlanta Area, GA
Yes, it does! Bertha has so many leaks on those primary seals, I don't know which of them are leaking... probably all of them.... 15 years is a long time for a seal.
Kind of like that penguin car joke... "Looks like you blew a seal. Nah... that's just a little ice cream!"
Kind of like that penguin car joke... "Looks like you blew a seal. Nah... that's just a little ice cream!"
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Intermediate
Joined: Dec 2009
Posts: 35
Likes: 0
From: Route 66 Az
Thanks guys for all the ideas, I think it would be a good idea to change the innner primary seals. First I am gonna clean the engine spotless and keep a close eye on any leaks. It looks like the derby cover was leaking a tad.
Road Master
Joined: Mar 2007
Posts: 814
Likes: 16
From: Hawaii
My drain plug leaks too. I've tried teflon tape, pipe sealant , gasket silicone and still no luck. I even bought a new drain plug (wasted my money). I changed out all the gaskets and I'm pretty sure it's the drain plug. I use ATF in the primary, RP in the trans and Mobil1 in the engine so I know it's coming from the primary. This is really pissin me off. Any ideas?