Rear Pumpkin Temperature?

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Lake Powell

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Rode home from work tonight, about 25 miles, mostly slab riding at about 80 mph, last 5 miles at about 40 mph. Outside temps were very mild, upper 70's and the riding was very low key, no heavy accelerating.

When I pulled into the garage I just thought I'd see how warm the rear differential felt, very hot!

Couldn't leave my hand on it for very long!

I have an 07' and the differential has had the fluid changed at around 600 miles and was refilled with Mobil 1 synthetic gear oil of the proper viscosity. The bike has just barely over 4000 miles on it total. The first oil change didn't show a substantial amout of particulates and seemed normal, the drain plug had very little in the way of metal on it, almost none.

I will pull the fill plug in the morning and check the level and report back.

Anybody have any info on this, too hot to touch makes me think there's a problem?

 
No idea, never even crossed my mind to see how hot is gets. I imagine it gets pretty doggone hot with all those moving things in there! As a reference on my 05, my frame just under the tank gets too hot to touch for more than a flyby by the end of each and every ride. Just the way it is and I suspect your rear end is fine. Someone with one of those fancy high flautin' infra red temp sensors should take a measurement; heck, I'd like to know the temp of the frame.

 
They run quite hot, high temp is normal. This does, however, illustrate the need for high quality lube, and a regular change interval-in my case, every oil change. The capacity is small, the cost of drain and fill low, the consequences of ignoring, well, we've all heard of the Miracle BMW Lubed For Life Miracle Final Drive.......... ;)

 
radman, Do you use the official "Yamaha formula" oil in the final drive?
Oooh it's morphing into an oil thread! :yahoo: I bet there is no way someone could hijack this into thread about cumquats, now that would be a real trick.

 
Actually, kumquat preserves are used by famous big name racers in a number of ways......... ;)
207620329_575a2fee5f.jpg


But, not being a famous big name racer, I use Mobil 1 ;)

 
Well it started out being helpful, I guess that's the most I could hope for......

Anyway talked to a few local area shops and the heat from the rear differential has been a noted issue for FJR's. So much so that Yamaha has a special differential fluid, just for the FJR.

P/N 9079E-SH001-00

This shit must be liquid gold because it was $31.50 for a pint bottle, actually 500ml.

I got a bottle and am right now changing the fluid.

BTW the fluid in the differential was right at the top, rather black and there was a small amount of filings attached to the drain plug.

 
Well it started out being helpful, I guess that's the most I could hope for......
Anyway talked to a few local area shops and the heat from the rear differential has been a noted issue for FJR's. So much so that Yamaha has a special differential fluid, just for the FJR.

P/N 9079E-SH001-00

This shit must be liquid gold because it was $31.50 for a pint bottle, actually 500ml.

I got a bottle and am right now changing the fluid.

BTW the fluid in the differential was right at the top, rather black and there was a small amount of filings attached to the drain plug.
It's new-to be expected. The final drive (it's not a diff) is reliable as a rock in this platform, basically same unit as used in the VMax and Venture and Virago for years. The key to keeping it alive, once again, is frequent changing of the lube-and the Yamaha Black Gold is not necessary, many, many here use Mobil1 gear lube and have seen great results with it. Your call.

 
It's new-to be expected. The final drive (it's not a diff) is reliable as a rock in this platform, basically same unit as used in the VMax and Venture and Virago for years. The key to keeping it alive, once again, is frequent changing of the lube-and the Yamaha Black Gold is not necessary, many, many here use Mobil1 gear lube and have seen great results with it. Your call.
This man speaks the truth.

 
It's new-to be expected. The final drive (it's not a diff) is reliable as a rock in this platform, basically same unit as used in the VMax and Venture and Virago for years. The key to keeping it alive, once again, is frequent changing of the lube-and the Yamaha Black Gold is not necessary, many, many here use Mobil1 gear lube and have seen great results with it. Your call.
This man speaks the truth.
I just replaced the pinion seal and pinion bearing at 57k. The bearing had some side to side play that I didn't like but the new one has the same play so I don't think it was needed. I live on a dirt road and it seems some grit worked its way into the seal.

Inside there was absolutely no way to tell it wasn't brand new. As long as the seals are good it should go forever. Couldn't find Mobil one here so I am using Redline synth.

 
Thanks for the responses.

My concern was with the temp of the case, it just seemed a little too hot.

I trust what you guys have to offer, and will change the rear case oil when doing the engine.

Thanks Radman, and your right, it's not a differential!

 
It's new-to be expected. The final drive (it's not a diff) is reliable as a rock in this platform, basically same unit as used in the VMax and Venture and Virago for years. The key to keeping it alive, once again, is frequent changing of the lube-and the Yamaha Black Gold is not necessary, many, many here use Mobil1 gear lube and have seen great results with it. Your call.
This man speaks the truth.
I just replaced the pinion seal and pinion bearing at 57k. The bearing had some side to side play that I didn't like but the new one has the same play so I don't think it was needed. I live on a dirt road and it seems some grit worked its way into the seal.

Inside there was absolutely no way to tell it wasn't brand new. As long as the seals are good it should go forever. Couldn't find Mobil one here so I am using Redline synth.
I think the Redline final drive oil is superior to the Mobil 1 and it's my oil of choice for the final drive in the FJR and the choice of all the lubricant requirements for my extensively modified Mustang. If not for the high moly content and the lack of JASO MA rating for the engine oil I would be using it in all the motorcycle engines. A neighbor of mine in my old neighborhood was a petrochemical engineer for AkzoNobel who was responsible for developing additives to blend for the oil companies was very impressed with the Redline products.

 
Rear ends will always run hot folks, no matter which; hardly any ventilation in that area. All 5 bikes I've owned with shaft final drive ran equally hot (Nighthawk S, Valkyrie, GL1800, BMW K1200RS, and FJR).

I do exactly what Radman does: change the fluid every oil change. A $7 bottle of Mobil1 75/90 usually lasts me 4 changes; cheap insurance, and it takes all of 5 minutes of labor to perform. With such frequent changes, you could probably use kitchen oil and be fine, so I wouldn't spend more than what Mobil1 costs, which is a fully synthetic oil, but that's just me. Later.

JC

 
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