It's gear oil in a gear box...changed every 20000 at the most...please... it will be fine.

 

I run Syn gear oil in the tranny and it cost more than Mobil 1 or HD Syn3 motor oil. If you think motor oil belongs in your trans it's your bike.

 

I used wally world synthetic 75/140 for 5000 miles and when I changed the oil last week, I was suprised at how clean it came out. I mean...it REALLY looked clean....and the plug was very clean also.

I replaced it with lucas heavy duty (non synthetic)

My question is......does the 2002 5 speed have soft metal synchros that require only GL-4?

I thought that the softer metals used as synchros had some form of anodized coatings on them now or were manufactured so the GL-5's did not adversely affect them?

FYI- Actually GL-4 gear oils do the same as GL-5's to soft metals....just at a much slower rate depending on the application.

 

Jeeze, just run formula+ and dont worry about it!

Tens of thousands of Harleys have run tens of millions of miles on it without ANY trouble.

 

True that.

 

Well I've got 111,000 miles on my 2000 S/E Road Glide. The last 70,000 on Mobil 1 75-90 Gear Oil in the perfectly running tranny.

I promise to let you all know when the tranny blows up.

 

[quote=Splais1;10026065]I still go back to the fact that Mbil's own site says NOT TO USE there GL-5 gear oil in the Harley transmission, that is all I need to know. I mean, if the manufacturer trying to sell as much of his oil as possible says NO, come on.

/quote]

Here's Mobil 1's Product Data sheet for 75W-90 Gear Oil. Where does it say not to use it in a Harley transmission?

HD tranny's were designed to run with gear oil. It was only in 2005 that they started putting Syn3 in their trannys, starting with the S/E Fatboy.

http://www.mobil.com/USA-English/Lub...LS_75W-90.aspx

 

That is good!...when I changed my oils, I got a bottle of formula plus for the primary....when I was changing the oils....the bottle said used for primary and tranny.....

Next change....formula plus it is.

I think I'll stick with the Harley oils too.

 

i don't care for formula + in the transmission. it's okay for the primary, but way more expensive than the rotella t.

tens of thousands of harleys have run tens of milions of miles on gear oil without ANY trouble.....

 

I'll bet I've run close to 250,000 miles in my last three Harleys with Redline Heavy Duty Shockproof, and I've never, ever had the slightest problem. I swear by that stuff! If you can't tell the difference when you drop it in your trans, something's wrong. Nobody can tell me it's not the best. But I also drop it out at 7,000 miles. It's the cheapest insurance you can possibly buy. Running Mobil 1 Syn 20W-50W in the crank and it comes out every 3500. Clean oil = clean engine. Simple math. Change it often and use good fluids. I don't think it really matters much what you put in the primary. I use Mobil 1 20W50W, but it's only because I'm **** about what goes in my scoot. I know guys that drop WalMart 10w40W in their primary, and they've never had any problems either. Your call. Your bike. But fluids for the engine of my bike are not something to cut corners on. It's just to cheap to go with the best imho.