VERY HOT rear diff/final drive housing.

[DobberDoo]

As long as it's less than this hot, you're ok:

(Sorry, couldn't resist)

Whoa!

 

[Talltourer]

We all have different tolerance for heat but after a little over an hour of riding, when I got home(last 3-4kms were at 40-50km/hr) It was hot but not "cant keep my hand on it" hot.

I just replaced the fluid with yamalube after break in(1100kms).

 

[Cycledude]

I worked a lot on drive axles and beval differentials. Gears and oil generate friction = heat. We spent a lot of time developing how much oil (level) and grade to meet OEM life targets of 1,250,000 miles!

You can expect (dependant on ambient temperatures) up to 70°C or 160°F would be my guess assuming correct oil level and no other issues. Maybe higher / maybe lower.

Hope this helps.

Don

I believe your numbers are pretty accurate, yesterday for a little experiment I switched to synthetic gear lube , after 100 miles I stopped the check the temperature with the Harbor Frieght gun, the outside temperature was 80 degrees, the final drive temperature was 157 degrees that’s the highest I’ve ever seen so I don’t think the synthetic lube cools much if any better than conventional gear lube.

 

[hobdayd]

Yep...done lot's of beval gear testing in my time.

But despite this heat the final drive should last several 100,000 miles.

 

[EricV]

It would seem to me that lower temps would indicate higher lubricity and possibly better heat dispersal properties of the oil. Neither a bad thing.

In some applications, like clutch type limited slip diffs for cars, too slippery is a problem. GL4 rated ok, GL5 not so much. I made that mistake in a Toyota Supra and had chatter in the diff until I swapped out for a GL4 rated diff oil.

 

[Tallyho]

Hello to you all, i am totally new to this forum (or any forum for that matter - First reply post!!!!)
i believe a hot final drive is a good thing, (except for the toasty caramel chocolate love sauce of the BMW's) temperature is the result of pressure and friction,
that S10 motor may not have the ponies of the ktm's but it sure is torqey'
and besides. you have the big long swing arm on the s10 to absorb any possible temperature spikes, i recently did 1200klm in one day and i put my hand over the final drive to see how it was, the entire swingarm had a warm touch, totally normal,
carry on till' you get carried out, K

 

[Sierra1]

I never checked the temps of the rear diff/final drive on my old RT; but I broke two of them. (on the same bike)