How warm does your bevel drive get?

[009jim]

Interested to know how warm other people's bevel gear case runs? I've just changed my bevel oil. I got a service receipt from the previous owner which itemised "gear oil" so I don't know more than that. I've replaced it with a Synthetic 75W-90 branded as BMW which I purchased at the local dealer. After previous rides, I used to place the palm of my hand on the bevel case and it was just comfortably warm. After yesterday's ride, which was my first ride with the new oil, the bevel case is now significantly warmer - it's now hot. I can still keep my hand on it for a long time, but it's not comfortable. I have to add that the weather here has been about 10 degrees C hotter the last few days.

[dirtrider]

10 hours ago, 009jim said:

Interested to know how warm other people's bevel gear case runs? I've just changed my bevel oil. I got a service receipt from the previous owner which itemised "gear oil" so I don't know more than that. I've replaced it with a Synthetic 75W-90 branded as BMW which I purchased at the local dealer. After previous rides, I used to place the palm of my hand on the bevel case and it was just comfortably warm. After yesterday's ride, which was my first ride with the new oil, the bevel case is now significantly warmer - it's now hot. I can still keep my hand on it for a long time, but it's not comfortable. I have to add that the weather here has been about 10 degrees C hotter the last few days.

Morning  009jim

 

It depends, at lower speeds in colder weather it just gets slightly warm, at a sustained 90 mph for an hour or more it will get hot enough to not keep my hand on. 

 

The drive has it's own internal gear tooth friction making heat as well as the  engine & catalytic converter heat blowing back on it. Plus rear brake heat can also add heat if a lot of braking.

[MT Wallet]

If it's a concern get a Harbor Freight {or other} laser thermometer and you can have some solid temp. data vs how it feels.

[Old School]

On 12/3/2023 at 4:27 PM, 009jim said:

Interested to know how warm other people's bevel gear case runs? I've just changed my bevel oil. I got a service receipt from the previous owner which itemised "gear oil" so I don't know more than that. I've replaced it with a Synthetic 75W-90 branded as BMW which I purchased at the local dealer. After previous rides, I used to place the palm of my hand on the bevel case and it was just comfortably warm. After yesterday's ride, which was my first ride with the new oil, the bevel case is now significantly warmer - it's now hot. I can still keep my hand on it for a long time, but it's not comfortable. I have to add that the weather here has been about 10 degrees C hotter the last few days.

I rode 40 miles at an average speed of about 65 mph this morning. Ambient temperature was around 60 F.  Within a couple of minutes of getting off of the bike, I reached down and put my hand on the final drive. I would call it luke warm.