When I changed my fluids, I put synthetic 75/90w gear oil in the transmission as it has always quieted down and improved the shift on other Harley's I have owned. Well the finding neutral problem also went away. It goes into neutral now easily every time. Always have thought you would not put gear oil in the engine, so why put engine oil in the transmission. BTW on the FLTSC you can easily change the fluids on the kickstand. Cut off a 1/2 gallon plastic jug and you can get the oil filter off with just a little bit of a spill.

 

I liked this...

 

How is the Breakout?

 

Corvettes use trans fluid in their transmission and they handle many times the torque load of a HD transmission. In addition there is no service interval. Never needs changing.

CVO's have come with Syn motor oil for many years not. Without ever an issue.

However I use BelRay. My dealer who throws in the !K service with a new bike uses only BelRay unless you request Formula + instead. So I just developed a habit of staying with BelRay.

 

The 75/90W gear oil really quieted the transmission and it continues to pop into neutral with no problem. Never going to put engine oil back in the transmission.

 

IMO it's because 20-50 motor oil is what MoCo designed the tranny to use!!.

I don't try to outsmart the engineers by using another oil than what it's supposed to have. If they came with gear lube, then I'd use it.

Even the Famous "" Amsoil"" doesn't recommend using Gear lube any more in a harley tranny.. And they have and now sell their own dedicated Tranny fluid..

https://www.amsoil.com/shop/by-produ...?code=MVTQT-EA

I've used a Syn 20-50 motorcycle oil in all three holes for 52K of the 53K mile and have never had an issue.

I did try some 75-140 syn GL once, dropped it out in less than 800miles.. too stiff..

Most new bike tranny's will be stiffer than they will once they get 5-10K miles on them...

My 07-- was famous for the 5th gear whine... but after about 10k it was gone..
I don't think it was the oils, it just needed some wear-in.

Use what you want. just saying IMO not everyone thinks GL's are better and IMO is not as good for the long haul..

 

I decided to stay with the way HD ships the bike. 20-50w HD motor oil and Formula + in the trans and primary. Works really well.

 

Im with you man..75/90 for me too..a perfect blend and yes it does shift better...wont get into brands but...oh and also Syn 20/50 motor and 10/40 primary...ride on every season..

 

I switched to Schaeffer's 75-90 back at 5000 miles. Couldn't really tell a difference, tran's not good, not bad, finds neutral most the time, small prob getting there once in a great while. I use the lever and it shifts, just like it did before. I'm gonna use Spectro 75-140 six speed next time around and if no change for the better I'll be done playing around and go back to 20-50 syn. Would of used Spectro first but Schaffers was easier to get for me. Those Baker boys seem to like Spectro pretty good anyway, but what would they know?

 

You don't really believe that do you!?!?

While I don't believe 10-50 motor oil will hurt an HD trans.... I don't believe for a second that the engineers "designed it" around a specific fluid....

The fluids the bikes are shipped with, and fluids recommended are primarily driven by bean-counters with an assist from marketing. The was a time when the Moco warned against synthetics, mostly because they didn't have an HD product to compete with synthetics. That's the way the world turns in the corporate world. And HD is not run by enthusiasts anymore...

The only engineering contribution towards fluids would be an opinion on whether or not whatever fluidt the Moco wants to use/recommend will damage anything before warranty runs out.....