Hello all,
Its been awhile and I have another question. First let me tell you I have a 2005 Fatboy 15th anniversary. Nice ride, I've been using the Mobile 1 V-Twin 20W-50 full synthetic in Oil, Trans and 75W-90 in the Gear box. All Changed every 5000 miles. Wanted to know is there something else I can use for the gear box? Seems the shifting is a bit loud (Klunky) and wasn't sure if this is normal. Also if I use something else there is it ok to have different lubes in the seperate areas?
Thanks!

 

I use a certain manufacturer's gear oil which is an 85W-140 Minimal clunk. Maybe just use a higher weight

 

The clunk is probably from the clutch (in the primary.) If adjusted correctly, any decent motor oil will handle that lubrication. (I run 20W-50 dino in there.) I have no issues with Mobil 75W-90 in my tranny.

 

I'm pretty sure that you'll find the answers here: https://www.hdforums.com/forum/oil-a...ted-topics-30/

 

redline

 

I tried both Mobil1 75w90, Mobil1 85w140 and Amsoil Severe Gear 75w90 in my trans and didn't notice any difference at all with shifting. Haven't tried any others.

 

Harley transmissions are clunky.

 

I run Redline Shockproof Heavy in my transmission, Mobil 1 15w50 in the engine, and regular Pennzoil 10w40 in my primary. Have done this for years. I change the engine and primary every 5k miles, but only change the transmission every 10k. However, many transmission fluid mfg's indicate you can run their fluid up to 20k miles.

 

This is what I use and if not Spectro then Bel-Ray.

 

It's not the gears, forks or dogs I worry about, it's the bearings, and I don't think they benefit from super heavy gear oil.