Just changed my crankcase oil w/Mobile 1 V-twin syn 20w50 want to change primary fluid should I be using the same oil? also want to change tranny fluid is Mobile 1 75-90 recomended? I just purchased the 2004 Roadking it has been upgraded to a six speed tranny, I believe I read some where that 6speed like 70-140? I see that some here use 20w50 in all 3 applications....I do not know the year of the Tranny conversion to 6 speed assuming that may make a diffrence, nor do I know what manufacturer of tranny...all I know is that it goes 6 gears lol.. thanks for the help in advance.

 

I have used the Mobil 75-90 synthetic in the tranny for over 15K miles now, works really well for me. I did go the Mobil 20-50 in the engine as well as the primary. Kept it in the engine and switched to the HD Formula+ in the primary. I like the Mobil products and have been using them like I said for over 15K miles(I know,not many miles, but finally made the switch to synthetics!), great product. To me, the primary is a swing vote as to what I used; functioned just as well with Mobil or HD products. I am sure others will throw in their 2cents worth!

 

I've read that alot of guys are using type F auto tranny fluid in their primary, I am trying it out now and it does seem smoother, and easier to get into netural. I had no complaints with the Redline MTL before this. I'm sold on the "pink peptobismo" Redlines heavy shockproof for the Transmission. Going from Redline 20w50 to Mobil 1 Syn. V-twin 20w50 next oil change in the engine.

 

The Primary is my least concern as far as longevity, but I also have heard a few with good results in shifting with the type F tranny fluid. My main concern is the choice of Tranny fluid, I am comfortable with Mobile 1 syn 20w50 in crankcase, thanks for the replies

 

Red Line Shockproof for me. They also make a primary fluid which I am gonna go with on the next change. Staying with Mobil 1 V Twin in the crankcase. Did LOTS of research and the specs on Mobil 1 are unmatched.

 

ATF+4 is said to last the life a 4X4 transfer case; there is often a chain in there. The same applies to recent automatic gearboxes that use wet clutches. My only concern in the primary transmission is the greater linear speed of the chain may require constant fluid viscosity that only a multigrade fluid can provide.

 

Mobile 1- 75/140 in tranny on 2011Tri Glide.

 

30+ years running synthetic, recently switched back to dino. got tired of all the noises related to the lack of cush in synthetic oil.

 

Welcome to the forum!

Oil questions are so frequent...that they created an actual topic heding for them...so if you wnat, you can research until you're tired about all of the combinations.

I use Redline Shockproof heavy in my transmissions. I love it.

For the primary......I use Redline Primary oil.

For the engine.....Mobil 1 15W50


www,myoilshop.com These guys have always done me right and FAST shipping.

~Joe

 

I switched from Mobil one 70/140 in my tranny to red line with shockproof. It quieted down the tranny a little. I use Mobil one 10w40 motorcycle oil in the primary.