Hi All.
I'm Ezra, from ISRAEL, riding an '06 Street Bob.
Living in ISRAEL mean that I cannot get all the high quality lubes you guys can get in the US.
Currently i have the HD Formula + the dealer put in my tranny & primary during the 1000mile service.
I now have 4000miles and want to change that.
I was able to find here regular, non-synthetic GL-5 rated 80W90 GearLube.
I put it in my tranny about 1200mile ago and it is great.


The question is, can I safely use GL-5 rated GearLube in my primary?
Or will I suffer from clutch slippage?

 

Ezra, I run 75w-90 gear lube in my primary. However any good crank case oil will work also.

Good luck, kick the crap out of Hezbollah!

 

I would stick with the HD Formula + in the primary.I think the gear lube would be too thick for the clutch.

 

Ezra,

My question would be why. Unless you have a shared primary/transmission like a Sportster, there would be no good reason to use a gearlube in the primary. All a primary needs is a non-energy conserving motor oil like any 10W-40 or 15W-40. Both are much cheaper than gear lubes and contain everything your clutch and primary chain need.

Yes, you can use HD's Formula Plus which by the way is a gear oil, but a 10W-40 might save you some money. To complicate things, many HDs have been running with ATF in their primarys which is closer to a 5W-20 than a 10W-40. (DO NOT USE A 5w-20 IN YOUR PRIMARY!)

One last note. Don't confuse gear oil viscosities wth motor oil viscosities. A 85W or 90W gear oil is about the same viscosity as a 40W or 50W motor oil. They are rated differently because of their intended tasks.

Honus (Steve)

 

I use redline MTL.........which is a GL4 with a real low pour point. You can use any synthetic motorcycle rated 20w50 motor oil or the mobil1 MTX 15w40 or Mobil1 15w50. But the HD Primary lube is fine. You might get some clutch drag with the 80w90 gear oil because its too thick. You want an oil in there that has no friction modifiers is possible. Use the 80w90 in your trans.

 

Thank you guys for your inputs.
The main problem we have here is that most of the oils sold in Israel are low quality Chinese stuff, name brands you guys never heard of and that are virtually impossible to get a component breakdown on.

To the best of my knowledge, HD formula+ (which b.t.w. retails for about 17$/quart here) is 50W; so wouldn't a 10W40 or 5W30 will be too thin in my primary (the weather here is pretty much like in Texas)?

If I put in my primary basic dino 20W50 SJ-rated car motor oil (Castrol GTX for example), is there a good risk that it would have friction modifiers? or would I be just throwing money away by using motorcycle specific oil?

Thanks for your help everyone.

Ezra
Tel-Aviv, Israel
'06 denim Bob

 

The 10w-40 would be OK, but the 5w-30 might have friction modifiers in it. The 20w-50 won't shouldn't have them, either. In your case, with the super high cost of the HD stuff, I'd go for the motor oil without friction modifiers. The primary doesn't need thick stuff, even in hot weather. Just keep the stuff that has the modifiers away from the clutch.

 

well, how do you know if an oil has friction modifiers or not?
is it that the narrower the viscosity spread, the less chance it will have them?
what about using straight 40W oil then?

 

If you can't get the motorcycle rated oils, I would bite the bullet and buy the HD stuff for the primary because it's still cheaper than replacing your clutch plates.

The one oil additive you want to stay away from for the primary is MOLY....great for the engine but not for the clutch. BTW, Harley Syn3 20w50 has no moly and you can use that too.

 

It's hard to say in your situation because the oils you have available to you don't necessarily have to meet the specs oils here in the US do. Here, 10w-40 and heavier do not have friction modifiers in them. And you can go with stuff that has some of the molybdenum additives; even the Mobil 1 V-twin 20w-50 has some in it. The straight 40 should be modifier-free, also.