Fatboy fluids question
Road Captain
Joined: Sep 2010
Posts: 574
Likes: 3
From: AB Canada
Most likely you have a main trans seal leak, same symptom on my 94 ultra, wouldn't leak on the lift, put it on the side stand, it would. Once you get the leak fixed, the 5 speeds need a good gear oil in them, I'm using Redline shockproof, and because I'm using it...it's the best oil to use.
Tourer
Joined: May 2011
Posts: 324
Likes: 8
From: Florida
"OWOF where did you find those statistics and what does everyone suggest? Mobil 1, amsoil or another?"
Awhlile back I was looking for a credible comparison when oil wars were taking place on another site. I don't believe this one to be biased although by Amsoil.
I won't recommend what anyone should use, however, I have no problem stating what I wouldn't use if it appears to be inadequate. I do use Mobil 1 syn except in my primary, and although the techs say it doesn't matter if you put syn in the primary, I don't because the primary oil is to cool the clutch.
In any case, I'm just providing some tech info that may assist riders in safeguarding their investment.
Awhlile back I was looking for a credible comparison when oil wars were taking place on another site. I don't believe this one to be biased although by Amsoil.
I won't recommend what anyone should use, however, I have no problem stating what I wouldn't use if it appears to be inadequate. I do use Mobil 1 syn except in my primary, and although the techs say it doesn't matter if you put syn in the primary, I don't because the primary oil is to cool the clutch.
In any case, I'm just providing some tech info that may assist riders in safeguarding their investment.
Thread Starter
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Advanced
Joined: Jun 2009
Posts: 64
Likes: 0
OK so I will probably start using a better oil, since the only reason I went cheap was because I was out of work. I will also get a different color (read more expensive too) trans fluid like redline shockproof. If I do redline in the tranny and the purple stuff in the primary, I will alswys know what fluid is leaking.
Can I use the purple in the primary??
One last questions since I am here...Is a main trans seal leak serious, in other words can I ride it as long as I keep tabs on the fluid level until I am ready to pull promaru apart or is it a stop riding and fix it immediately issue. I understand the gamble here.
Can I use the purple in the primary??
One last questions since I am here...Is a main trans seal leak serious, in other words can I ride it as long as I keep tabs on the fluid level until I am ready to pull promaru apart or is it a stop riding and fix it immediately issue. I understand the gamble here.
Seasoned HDF Member
Joined: Mar 2009
Posts: 24,684
Likes: 9,167
From: Snow Hill, NC
Viscosity Index: Castrol ranked 2nd to last out of 17 brands
Viscosity Shear Stability: Castrol ranked 3rd to last out of 17 brands
Rust Protection: Castrol ranked last out of 17 brands
High Temperature / High Shear Viscosity: Castrol ranked 4th to last out of 17 brands
Wear Protection: Castrol ranked 6th to last out of 17 brands
Oxidation Stability: Castrol ranked 6th to last out of 17 brands
Foam Control: Castrol ranked 6th to last out of 17 brands
I understand oils have to meet SAE requirements etc, but their V-twin oil is poor by comparison. Realizing the temps HD's run I' would advise against it. I'm not an expert. Castrol braggs about thermal breakdown protection and failed miserably on the viscosity test. And It didn't do well on the wear test. I ride the hell out of my bikes, and frequently change the oil. But if an oil is going to fail under certain conditions, it doesn't frequent changes may not prevent damage.
I know a lot of people swear by RP. I tried it in my Supercharged car and within a week noticed purple drips under it which became progressively worse every few days. I removed it under advice of the guy that built the superchargers and worked for GM, and after removal, it sealed back up and no more leaks. Just my experience.
Viscosity Shear Stability: Castrol ranked 3rd to last out of 17 brands
Rust Protection: Castrol ranked last out of 17 brands
High Temperature / High Shear Viscosity: Castrol ranked 4th to last out of 17 brands
Wear Protection: Castrol ranked 6th to last out of 17 brands
Oxidation Stability: Castrol ranked 6th to last out of 17 brands
Foam Control: Castrol ranked 6th to last out of 17 brands
I understand oils have to meet SAE requirements etc, but their V-twin oil is poor by comparison. Realizing the temps HD's run I' would advise against it. I'm not an expert. Castrol braggs about thermal breakdown protection and failed miserably on the viscosity test. And It didn't do well on the wear test. I ride the hell out of my bikes, and frequently change the oil. But if an oil is going to fail under certain conditions, it doesn't frequent changes may not prevent damage.
I know a lot of people swear by RP. I tried it in my Supercharged car and within a week noticed purple drips under it which became progressively worse every few days. I removed it under advice of the guy that built the superchargers and worked for GM, and after removal, it sealed back up and no more leaks. Just my experience.
Give me a break...he changes the motor oil every 3000 miles and other 2 at 6000...Put the KOOLAID cup down man....Castrol would be out of business if their products was as bad as you make it out to be....Many members here use it and have rode hundreds of thousands of miles with it...
Seasoned HDF Member
Joined: Mar 2009
Posts: 24,684
Likes: 9,167
From: Snow Hill, NC
OK so I will probably start using a better oil, since the only reason I went cheap was because I was out of work. I will also get a different color (read more expensive too) trans fluid like redline shockproof. If I do redline in the tranny and the purple stuff in the primary, I will alswys know what fluid is leaking.
Can I use the purple in the primary??
One last questions since I am here...Is a main trans seal leak serious, in other words can I ride it as long as I keep tabs on the fluid level until I am ready to pull promaru apart or is it a stop riding and fix it immediately issue. I understand the gamble here.
Can I use the purple in the primary??
One last questions since I am here...Is a main trans seal leak serious, in other words can I ride it as long as I keep tabs on the fluid level until I am ready to pull promaru apart or is it a stop riding and fix it immediately issue. I understand the gamble here.
Seasoned HDF Member
Joined: Mar 2009
Posts: 24,684
Likes: 9,167
From: Snow Hill, NC
Viscosity Index: Castrol ranked 2nd to last out of 17 brands
Viscosity Shear Stability: Castrol ranked 3rd to last out of 17 brands
Rust Protection: Castrol ranked last out of 17 brands
High Temperature / High Shear Viscosity: Castrol ranked 4th to last out of 17 brands
Wear Protection: Castrol ranked 6th to last out of 17 brands
Oxidation Stability: Castrol ranked 6th to last out of 17 brands
Foam Control: Castrol ranked 6th to last out of 17 brands
I understand oils have to meet SAE requirements etc, but their V-twin oil is poor by comparison. Realizing the temps HD's run I' would advise against it. I'm not an expert. Castrol braggs about thermal breakdown protection and failed miserably on the viscosity test. And It didn't do well on the wear test. I ride the hell out of my bikes, and frequently change the oil. But if an oil is going to fail under certain conditions, it doesn't frequent changes may not prevent damage.
I know a lot of people swear by RP. I tried it in my Supercharged car and within a week noticed purple drips under it which became progressively worse every few days. I removed it under advice of the guy that built the superchargers and worked for GM, and after removal, it sealed back up and no more leaks. Just my experience.
Viscosity Shear Stability: Castrol ranked 3rd to last out of 17 brands
Rust Protection: Castrol ranked last out of 17 brands
High Temperature / High Shear Viscosity: Castrol ranked 4th to last out of 17 brands
Wear Protection: Castrol ranked 6th to last out of 17 brands
Oxidation Stability: Castrol ranked 6th to last out of 17 brands
Foam Control: Castrol ranked 6th to last out of 17 brands
I understand oils have to meet SAE requirements etc, but their V-twin oil is poor by comparison. Realizing the temps HD's run I' would advise against it. I'm not an expert. Castrol braggs about thermal breakdown protection and failed miserably on the viscosity test. And It didn't do well on the wear test. I ride the hell out of my bikes, and frequently change the oil. But if an oil is going to fail under certain conditions, it doesn't frequent changes may not prevent damage.
I know a lot of people swear by RP. I tried it in my Supercharged car and within a week noticed purple drips under it which became progressively worse every few days. I removed it under advice of the guy that built the superchargers and worked for GM, and after removal, it sealed back up and no more leaks. Just my experience.
Oil choice is very personal and everyone will have an opinion that may or may not be right...Yes including me...
By the way i don't use Castrol....
I don't think i have heard of a failure on a motorcycle here because of using whatever oil brands used...The biggest factor here is changing it within manufacturer specs. and i think you will agree he is well within that..
A friend of mine has a 2004 Honda Goldwing and has 235000 miles on it...he has been using Castrol GTX Dino oil in it since the first oil change...he goes as far as 10000 miles between changes...
Stage I
Joined: Feb 2012
Posts: 1
Likes: 0
From: australia
Hi, There is red primary fluid you can use, I live in Australia and my local motorcycle parts store has it. Someone mentioned above 'redline', I think there red as well. I'd be cleaning the bike up really good (especially behind the primary), then change your primary oil (like you said a different color to your engine and transmission oil) and then determine what oil is leaking. Keep in mind usually the leaking oil will change color before it hits the ground as a leak, (due to road grime/grit/bike dirt etc.) but you should still be able to determine what oil it is. If you detemined that it's primary oil and pull the inner primary off, make sure you buy a good oil seal and make double sure to seal all the bolt heads with a sealent. I'm just going through a nightmare with an 1985 fxst that just refuses to stop leaking from the primary seal (I know it's the primary because the fluid is red), I have done over 10 primarys of these bikes in the past year and I have not had a problem (different bikes that I sell) but this one is become a real pain. I'm almost at a point of buying a new inner primary. we'll see.
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Club Member
Joined: May 2007
Posts: 145,895
Likes: 821
From: 40 miles Northeast of Indy..
Ur oil isn't causing the leak, it something else.
If Ur using regular car oil in the pri, I wouldn't recommend that, because it has friction enhancers thats not really good on the clutch plates.
Use whateven U want in the motor but most use some kind of motorcycle V-twin in the primary and I personally like a 75-90 weight GL in the tranny. I just happen to like Mobil 1 V-twin stuff, but use what U want.
If Ur using regular car oil in the pri, I wouldn't recommend that, because it has friction enhancers thats not really good on the clutch plates.
Use whateven U want in the motor but most use some kind of motorcycle V-twin in the primary and I personally like a 75-90 weight GL in the tranny. I just happen to like Mobil 1 V-twin stuff, but use what U want.