My 08 SERK came with SYN 3 in all 3 holes. I'm running M1 V-Twinn & M1 Synthetic gear lube along with F+ in the primary on my 07 Dyna. The dealer says SYN 3 is what should be in my SERK and to keep using it. Whats the consensus on this. Is SYN 3 bad or is M1 better for the crankcase and is M1 gear better in the tranny....SYN 3 is probably OK in the Primary but I have a problem understanding how one lubricant can be OK for all 3 holes when they all have differing requirements. I'm leaning towards going with M1 V-Twin on my SERK....Advice please?

 

There are a bunch of threads on this topic just do a search for Mobile1 or Syn3.

The consensus seems to be Mobil 1 V-Twin or other synthetic in the Oil bag and Primary and Mobil 1 75-90w gear for the Tranny. You can use the v-twin oil in the tranny also but most find the thicker lube shifts better. Just do a search and then browse the topics.

 

Well, agree with the Mobile One or Amsoil or Redline instead of Syn III BUT
many also use Redline HD Shockproof in the Tranny. Best there is , IMHO.

EZ

 

My manual for my 2007 FXDSE says the same thing to put it inall the 3 holes, but I am gong to switch to Amsoil.

 

If you wouldn't put gear lube in the engine, why would you use engine oil in the transmision?

Use a gear lube of your choice in the trans and engine oil in the engine, I prefer Mobil1 V Twin. Forget what the dealer is pushing on you.

 

You're dealer is just interested in selling you oil. Forget what he says. I'd run Mobil VTwin in the motor, HD Formula Plus in the primary and Mobil 75W90 synthetic gear oil in the trans. Do what's best for the bike and gives you piece of mind rather than improving the dealer's profit margin.

 

Thanks ...Thats what I'am already running on my 07 Dyna and have no problems. I went there to get F+ and a filter to do the change on the King the day after I picked up the bike as I wanted the SYN 3 out of my bike as soon as I could and my sales guy goes into all this about how HD designed it for all 3 holes, I would'nt do it, etc, etc.....guess thats why he's a sales guy....Thats why I wanted to throw this question out here and get re-affirmation that I'm OK dumping the SYN3. I'm not a rocket scientist but common sense says we've got 3 totally different conditions where these fliuds operate, one type for all 3 holes can't be better than having a fliud designed for each specifically. ...Thanks again!

 

A lot ofsales guys don't know squat about these bikes, they are just there to sell. I've seen a few that couldn't answer any questions about the bikes themselves and that is poor business IMO.

If you are relying on them to give the proper advise on oils now, we're in bad shape.

 

Use what you are already using in your 07 Dyna.