Ok....I have read and read, and read some more on primary fluid for these Sportsters that at this point I know I am beating a dead horse with this thread.

That said I am servicing my bike for the season and it's time to change the fluid. I am running Mobil 1 75W90 in it. I went to find some and could only find Valvoline Synthetic 75W90, so I bought the quart. But before I changed it, I stupidly began to surf the net for what everyone else runs. Mobil 1 75W90 is generally the most common oil encountered but I read on other forums about not using a GL-5 gear oil in the primary as it could damage it over the long run, etc and to use a GL-1 if you can find it? Am I good to use this quart of Valvoline Syn 75W90 or should I look for something else? Will using a GL-5 spec gear oil damage the transmission over the long run, should I chock that up to internet hogwash?

 

Is the GL-5 dino squeezin's or synthetic? make sure not to mix the two types. Past that, I dunno.

 

never mind, doh!

 

The best stuff I've ever used is the HD brand made for Sportsters, Can't recall the name right now. I ran Synth. oil in the crankcase, and that in the primary, never had a problem.

 

Don't run syn in your primary, it's gonna cause slipping down the line. It also offers no real advantage over dino anyways. Run the dino and be done with it. After years of daily riding, I can tell you for sure that syn will have you replacing clutch plates soon enough. It actually over lubricates them. Put more thought into your crank case. That's where you'll see the real difference anyways.

 

Also that whole "once totty go syn you can't go back!" Thing is bs. If you know how to correctly change oil in anything you will never have problems doing that.

 

Once *you....stupid swype...is that even a word! ?

 

Use HD Formula +
and you will feel the difference,,
Or don't,,Its your bike

 

I bought my Sportster (see sig) used last fall and have changed engine oil twice with no problems. Last night i decided to also change the oil in the gearbox too.
I drained it and put in 1 quart of Mobil 1 75W-90 gear lube, it now makes a lot more noise than before (used to be whisper quiet) and shifting is not as smooth as before. I do not like it one bit.
The oil i drained out of the gearbox had that sulfur gear oil smell to it so i can only assume it was gear oil but not Mobil 1. I am also assuming that at 7,800 miles it had not been changed previously unless that's part of the 5k service.
What gear lube does HD use at the factory & when servicing?
Do you think switching to HD formula+ will get me back to quiet & smooth?

 

It Made Mine super quiet and smooth,,
It's what Is reccomended by HD,,
It's made for our tranny n clutch,,
I change It every 5,000,,,
The factory Installed oil needed to be changed at 5k so I did,,,

Why the hell would I wanna run any synthetic ? I'm not gonna leave
It In for 10,000 anyways.
GL-5 Based Lubricants IMO from my research can deteriorate certain
materials in the Stator over time,,,long time Im shure,,But why risk It.
And no I'm not gonna reserach all that again,,too time consuming.
Most will not agree with me anyways and thats fine.

Synthetics In the primary are too slippery IMO

I tried an old well known product from Bel-Ray,,said on the bottle,
made for sportsters,,,75 miles later It was OUT,,DRAINED,,
I was not gonna run with my gears n clutch shifting like crap.
IMO The Bel-Ray sportster tranny fluid would have destroyed my tranny
In short order..

HD formula+ Is In there now and I will never run anything else,,,

Thats my story an I'm stickin to it,,,,

Most think the "Clunk" In a sportster tranny Is normal,,,thats fine with me
But mine don't "Clunk" all the time anymore an I'm happy...
The first morning drop into 1st gear sometimes does "Clunk" BUt not as bad and not all the time.

My advice,,,TRY the "HD Formula +",, Go On,,I dare ya XD