transmission oil change
Road Master
Joined: Nov 2012
Posts: 1,027
Likes: 69
From: Centerville, ohio
There are many choices and opinions but most recommend a gear oil in the trans vs a motor oil. I run Bel-Ray Gearsaver Hypoid 85/140 myself.
Last edited by lt1-xjs; Mar 5, 2014 at 02:10 PM.
Seasoned HDF Member
Joined: Mar 2009
Posts: 24,709
Likes: 9,209
From: Snow Hill, NC
I have run 20W50, 75w140, 75w90 and formula plus and really haven't seen any difference.... As long as you have something in there... Leave it in for 20000 miles ...The 75w140 is pretty sticky...I think i have Formula plus in now because it's easy to get and halfway reasonably priced. It's what the manuals says to use also.
Tourer
Joined: Jun 2008
Posts: 306
Likes: 7
From: Somewhere, PA
I'm in the crowd that motor oil has no place in a gearbox. I have a few friends who are also HD techs who can't believe the factory went with the Syn-3 in all three holes approach. I stick with dino 75-90 or 75-140 in my older Pans/Shovels and usualy run synthetic 75-90 in the Evos and Twinkies. Works for me.
Tourer
Joined: Aug 2009
Posts: 364
Likes: 8
From: Newberry SC
There is some difference in how the viscosity is rated for gear oils compared to engine oil. I wish I could remember where I found it -- maybe the BobIsTheOilGuy forums?? -- but the higher gear oil viscosity numbers were pretty much the same equivalent as the engine oil viscosities we use.
Anybody got a reference about that?
'fooz
Anybody got a reference about that?
'fooz
Road Master
Joined: Sep 2004
Posts: 892
Likes: 8
From: Central Florida
I'm no scientist, but I remember reading something about "shear." Transmissions chew up the molecules pretty good. Gear oil is more resistant to that than motor oil (I believe) I use Spectro Platinum Six Speed synthetic gear oil in my 07. They have something else for the 5 speeds.
Seasoned HDF Member
Joined: Jan 2007
Posts: 20,616
Likes: 4,440
From: anacoco, la
you don't say what bike you have, but i've heard that with the new anti-slip, limited slip, whatever they call it transmission, that you don't want to run 75-140, that 75-90 is fine.
i'm also in the camp to run gear oil in the tranny, and engine oil in the engine. and yes, i also read about the similarity in viscosities between 20-50 and gear oil. it was on bitog.
i'm also in the camp to run gear oil in the tranny, and engine oil in the engine. and yes, i also read about the similarity in viscosities between 20-50 and gear oil. it was on bitog.
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Tourer
Joined: Aug 2009
Posts: 364
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From: Newberry SC
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Road Warrior
Joined: Nov 2013
Posts: 1,552
Likes: 81
From: Largo, FL
The techs at my dealership say they prefer the Belray tranny fluid, and that it quiets the shifts down a bit. I'm going to try it at my upcoming 5k service. I thought Syn3 was kinda thin for the tranny too, no wonder it thunks and clunks.
Ultimate HDF Member
Joined: Apr 2010
Posts: 7,138
Likes: 26
From: Southern Oregon
I switched to redline v twin with shockproof. Other than the smell there was no noticeable difference. Was thinking about going back to oem juice next change, might give belray a try