Tranny Oil

[BaggerDad]

I change the oil in my engine fairly frequently but not the trans. Should I change trans oil every time I change the engine oil?

And any thoughts on synthetic vs mineral oil for trans?

[lowrider01]

I change engine oil,oil filter,primary,trans everytime i service my bike, I also use synth oil,Amsoil,in everything,when i started using their gear oil in trans,i noticed alot smoother shift,so i still use it,i like the synth oils,that's just my pref,ther are quite a few other good brands out there.but i did notice a better shift when i started using the amsoil gear oil.

[hdnt1550]

I will change my primary and trans every other oil change.
I used to use syn3 in everything but changed back to normal primary and trans lube.

[tipper1]

I use harley syn3 or mobil 1 vtwin 20-50 in eng and pri.
use mobil 90-140 syn in trans. I change all 3 everytime. These reccomen dations were in a 2002/2003 Aim mag by a Mobile 1 tech who did an article for them. It works for me the 90/140 gear oil quiets the tranny when shifting....By the way in an email conversation with mobil tech he suggested but didn't confirm that mobil makes the syn3

[Buzz Kanter]

Originally Posted by hdnt1550

I will change my primary and trans every other oil change.
I used to use syn3 in everything but changed back to normal primary and trans lube.

Curious why you switched back from syn oils?

[Chris L]

Not sure the gearbox needs changing every time, I used to change all 3 at 2500 intervals and the gearbox oil was as clean as when I put it in, so now 5000, whereas the primary looked dreadful, lot of metal in there thrashing about, so that still gets a 2500 change...Formula+ in both. Engine- Harley20/50 or Revtech 25/60.

[evoKENevo]

I'v been changing trans-fluid annually (after winter lay-up) and had been OK with HD's semi-synth. This spring I decided to give Amsoil's "Severe-Gear" a shot..and,am not happy with it. Because I can actually HEAR the trans "whirring". A couple of friends swear by Red Line's (not readily avail. around here) "shock-proof"...thicker,quiet,smoother shifts,ect...and one of them just got a case (six qts) of it, a couple days ago, to split-up...will see him Sat.,and give IT a shot.

[HarleyCruiser]

Changing your oil, your gear lube should depend more on your riding style than your miles.
First Harley recommends every five thousand, both on motor and gear, primary. (look in your manual)
Dealerships and oil companies, are the ones that push the 2,500 mile oil changes
With their syn oil Harley upped the trans to 15 thousand if my memory is right.
If you ride on a lot of dirt roads, short trips, or don’t put a lot of miles on the bike then you need to change it more frequenty.
Especially in the winter where moisture can form and not be burned off with short trips.
At 2500 Harley recommends you INSPECT the oil, they don’t say replace it. And this does not mean just checking it. Inspecting your oil is looking at the color to see if it is white, meaning water, seeing if it is black/dirty and feeling the viscosity by squeezing it between your fingers and seeing how slick it is.
You also want to smell it, especially in the summer in extreme heat. Smell for burnt oil.
Also, look for any color specks, metal or plastic.
When I was a kid, the old mechanics would taste it, but I dont go that far.
If you have burnt oil, moisture, or a lot of dirt, you need to change your riding habits, or have more frequent oil changes.
If you have color specks, (metal or plastic) pull off your filter, and cut it open to see how bad the problem is.
I run Mobil one, everywhere with syn gear lube in the trans.
It does Shift smoother, and solved a down shifting problem that I had.
I change my engine oil every 5k, but have known to go 7000 miles on a change, (Especially if they are road trip miles) keeping a close eye on the oil.
At 7000, it still looked fine, but was starting to show its age.
I change my gear lube every 10 but would not worry about going 20,000, but I rack up the miles pretty quick.
One last note, don’t want to start a oil thread, but not everyone needs synthetic oil. It depends on your riding habits. If you run a lot of miles, synthetic pays for itself. If you run in real hot climates you should run synthetic, it runs cooler and does not break down, like conventional oil.
If you put on four thousand miles a year, and are not going to keep the bike forever; If you change the oil every 2500 k, because you feel better; and live in Maine save your money and run conventional oil.

[Fenderplayer]

I've changed mine at 5k service intervals, but it looked almost as if I could pour it right back in. I use 90-140 syn gear oil and it quiets the tranny down quite a bit and seems to shift and find neutral easily.

[myt evo]

I use Spectrol 75/140 in the gearbox. Always used it in my evo and will continue to do so and now in my new road king. Just remember to use gearlube that is made specifically for the 6-speed.