I can see a whole new debate arena opening up -

Is dino or syn oil best in the transfer case?
By looking at your Sig Pic, Yes, your bike is subjected to much more heat and synthetic will serve you better. Use Amsoil it's a Tad better than Mobile One.

Do I have to use bike specific oil in my transfer case?
Use any oil you wish, putting it in your bike makes it 'Bike Specific'.

Will friction modifiers damage my gears or chain?
Not unless you do the clutch re-location Mod should you worry about this. Any GL 4 will do, but not any GL5 unless it's backwards compatible.

Can I put Lucas additives in my transfer case?
You can put Raisin Bran in your transfer case, we just don't know yet if it's good for it. What's Lucas's 1st name?

Do I need to put new oil in my transfer case before winter storage?
Yes, the suspended chemicals in the oil will eat your chain and gears over winter if not, in spring you'll think your clutch went bad and end up replacing that and the contents of the transfer case.

I'm an Amsoil dealer, I know everything so trust me. Doc does.

DocShadow wrote:
Engine oil also has antifoaming additives .... but I agree re the chain foaming up the oil.

The question really to be answered is ..... Do we need the extreme pressure additives present in GL4 oil?

I'm leaning toward the NO camp. Having looked at the innards of the tranny, I cant' see it being any different that some other engine chain applications. You would need thicker oil as only the bottom part of the chain is immersed in the oil. A light oil would not provide the lubrication protection needed as the chains spins around.

Chain bar oil .... that's and interesting idea.

Doc

Yeah, just kidding about the chain bar oil, but you had a good point. The gears and chain do seem to be comparable to a timing chain/gear set up.

Imagine an Amsoil Dealer promoting Amsoil. I think I'll just go by the book. Yamaha designed it, hopefully they know how to take care of it.

I’ve started prepping my bike for a road trip. BTW- it’s a 2006 with 42,000 miles. Done most of the work and now I’m down to the differential gear lube and have put Mobil 1 in the last 3 times. Went to buy some more and noticed that the jug now is labeled Mobil 1 Synthetic Gear Lube LS 75W – 90. Looking at Mobil’s web site it states this:

"Mobil 1 Synthetic Gear Lube LS 75W-90 contains special friction modifiers designed for limited slip-type differentials. Mobil 1 Synthetic Gear Lubricant LS 75W-90 meets the most severe API Service MT-1 and GL-5 EP gear oil service classification. Mobil 1 Synthetic Gear Lubricant LS 75W-90 can also be used in rear axles where API Service GL-4 lubricant is recommended"

I haven’t put it in yet. The “LS” and special friction modifiers have me wondering. Thoughts??? Comments???
Also, is 90W is good would the 140W be better?

Most Amsoil dealers buy more oil than they sell, That's me too. Once you really study up, it is good stuff. So I may be a dealer but you never see me pushing using my dealer number here. I also use Lucas in class 8 equipment with real good results. I'd also use Mobile one in a heartbeat. But not much else.

Anyways, I would not use the heavier gear lube. I would not even use the GL5 that's says it's also GL4 compatible. Just leery of that. As Doc posted, it may even be worse for it. So being I am not understanding how they can say it's GL 5 but yet GL 4 compatible also is a contradicting claim. I believe it can be done because Amsoil does it, but I would not use it unless I understood the hows and whys.

Also I noticed AMSOIL Motorcycle 20 W 50 says right on the box also good for a gear box where GL1 is recommended. I know I sell a lot of it to Hardely guys and they use it in gear box.

I also looked at AMsoil's Severe Gear lube and I saw something on that carton that would lead me not to want to put that in either. I'm going with the book on the Transfer Case.

BlkDakDave

Agree with BlkDakDave ... you don't want to put thicker oil in ... it just causes more drag.

I never was a fan of putting in GL5 in the transfer case .... a higher number does not make it better and I know it not good for bronze or copper.

Doc

BlkDakDave wrote:
I’ve started prepping my bike for a road trip. BTW- it’s a 2006 with 42,000 miles. Done most of the work and now I’m down to the differential gear lube and have put Mobil 1 in the last 3 times. Went to buy some more and noticed that the jug now is labeled Mobil 1 Synthetic Gear Lube LS 75W – 90. Looking at Mobil’s web site it states this:

"Mobil 1 Synthetic Gear Lube LS 75W-90 contains special friction modifiers designed for limited slip-type differentials. Mobil 1 Synthetic Gear Lubricant LS 75W-90 meets the most severe API Service MT-1 and GL-5 EP gear oil service classification. Mobil 1 Synthetic Gear Lubricant LS 75W-90 can also be used in rear axles where API Service GL-4 lubricant is recommended"

I haven’t put it in yet. The “LS” and special friction modifiers have me wondering. Thoughts??? Comments???
Also, is 90W is good would the 140W be better?

If it says it can also be used for GL4 applications, it is okay. GL5 has extreme pressure/temperature wear additives in the form of sulfur (molybdenum disulphide) that are engineered to become active at different temps. This is done so the oil layer will remain throughout the temperature range. These additives are what maintain the oil film between the gears in extreme pressures and in low temps and high temps. These additives can form acids that will eat yellow metals like bronze and copper. The difference between GL4 and GL5 is that GL4 has about half the amount of these additives. The sulfur additives in GL4 will still eventually attack the yellow metals but usually long after the service life of the component it is used in. GL5 rated lubes that also say they are compatible with GL4 applications have altered this additive package so that it will be more compatible with GL4 applications, but it probably still has more additive than the dedicated GL4 lubes. I don't know that there are any yellow metals in the R* transfer case, but Yami calls for GL4. Also, I am not sure of the amount of the needed additives the transfer case requires that are in engine oil. Two good reasons I will stick to GL4 gear lube that yami recommends.

blkDakDav..........the debate go's on gl4..gl5 i read in another thread that mobile one syn gl5 was backward compatable gl4 is this wrong?I haven't changed my trans case yet! again welcome blkdakdav a wealth of knowledge on here doc and these guys help alot!

slezy wrote:
blkDakDav..........the debate go's on gl4..gl5 i read in another thread that mobile one syn gl5 was backward compatable gl4 is this wrong?I haven't changed my trans case yet! again welcome blkdakdav a wealth of knowledge on here doc and these guys help alot!

Mobil 1 synthetic gear lube is GL5 rated that can also be used in GL4 applications according to Mobil.