rearend gear lube questions

[dwhartwell]

The point of the bits of information was to make a point coming from reputable sources. NOT "well I've been doing this or that for years and I've not had a problem"
Lastly, I found on the Yamaha site for the first time, specific information that states to use 80W GL4 gear oil. So, for what it is worth Yamaha is stating that GL4 is acceptable and GL5 is not.

No. That is not what it says. Nowhere does it say that GL-5 is not acceptable. (FWIW I have had the same "Service Specs" pdf file in my possession since I bought the bike). It simply specifies "Oil Type SAE80API "GL4" Hypoid Gear Oil" as being appropriate. Just because GL-4 is specified does not necessarily mean that GL-5 is inappropriate.

If GL5 was acceptable, then it would be stated GL-4 / GL-5. My son's 99 Jeep Wrangler manual transmission states GL-3. It does not state anywhere in the documentation (that I've seen) to NOT use GL-5. It is when you dig into the details that you find that GL-5 in these transmissions eats the syncros. So I do not agree with your statement based upon the facts that I've found to date. This is out of the 99 Wrangler factory service manual... "RECOMMENDED LUBRICANT

Recommended lubricant for AX15 transmissions is Mopart 75W–90, API Grade GL–3 gear lubricant, or equivalent." If you dig into the details you will find that GL-4 superceded GL-3. GL-5 does not superced GL-4.

 

[juniorfjr]

I can't believe we have a thread about lube in a rear end and Bust hasn't replied yet. What the hell is happening to this forum.

 

[dwhartwell]

So looking at this and the FJR shop manual it appears that there are 2 bronze bushings/bearings in the final drive assembly. One on the pinion gear that fits on the end of the pinion gear closest to the ring side (opposite driveshaft side) , the and other if you look carefully at the photo of the ring gear is the photo of the referenced page you will see what appears to be a bronze bushing/bearing in the center of the ring gear. Looking at the shop manual, the fact that they want these lubricated while the ball bearings call for no lube plus the fact that the drawings do not show enough space for a ball/roller bearing suggest that they are bronze. SO..... for what it is worth, this "MAY" be why GL-4 is required. I also noted when I changed the final drive fluid on my 6K mile 07, that there appeared to be fine bronze particles in the old oil.

Has anybody pulled the final drive assembly fully apart that can confirm or deny this?

Mark Johnson's FRJ Site - Final drive

 

[Fred W]

So looking at this and the FJR shop manual it appears that there are 2 bronze bushings/bearings in the final drive assembly. One on the pinion gear that fits on the end of the pinion gear closest to the ring side (opposite driveshaft side) , the and other if you look carefully at the photo of the ring gear is the photo of the referenced page you will see what appears to be a bronze bushing/bearing in the center of the ring gear. Looking at the shop manual, the fact that they want these lubricated while the ball bearings call for no lube plus the fact that the drawings do not show enough space for a ball/roller bearing suggest that they are bronze. SO..... for what it is worth, this "MAY" be why GL-4 is required. I also noted when I changed the final drive fluid on my 6K mile 07, that there appeared to be fine bronze particles in the old oil.
Has anybody pulled the final drive assembly fully apart that can confirm or deny this?

Mark Johnson's FRJ Site - Final drive

Dunno. But this is where I was headed with my questions as well. I had previously looked through Mark's site and (still) don't see any bronze bushings, but that doesn't mean that they aren't there.

 

[dwhartwell]

So looking at this and the FJR shop manual it appears that there are 2 bronze bushings/bearings in the final drive assembly. One on the pinion gear that fits on the end of the pinion gear closest to the ring side (opposite driveshaft side) , the and other if you look carefully at the photo of the ring gear is the photo of the referenced page you will see what appears to be a bronze bushing/bearing in the center of the ring gear. Looking at the shop manual, the fact that they want these lubricated while the ball bearings call for no lube plus the fact that the drawings do not show enough space for a ball/roller bearing suggest that they are bronze. SO..... for what it is worth, this "MAY" be why GL-4 is required. I also noted when I changed the final drive fluid on my 6K mile 07, that there appeared to be fine bronze particles in the old oil.
Has anybody pulled the final drive assembly fully apart that can confirm or deny this?

Mark Johnson's FRJ Site - Final drive

Dunno. But this is where I was headed with my questions as well. I had previously looked through Mark's site and (still) don't see any bronze bushings, but that doesn't mean that they aren't there.

Here is a link to the shop manual. Note that 17 & 18 require pre-lubing while the roller/ball bearings do not. I've also noted in the other sections of the manual that 17 & 18 do not take up much physical space. My bet is that they are bronze bearings/bushings

Service manual page

sorry I've not found a way yet to post bigger shots. Any suggestions will be appreciated.