Viscosity and temperature

[Sniffy]

Hi Everyone,
First post.
I have a 2008 Bobcat v518 telehandler that has a bit of a heating issue after prolonged use. In temperatures above 75-80f driving around with the hydro-static drive will cause the oil temps to heat up. I'm currently using fresh AW46 oil and the previous oil sample didn't show any issues. It has under 2000hrs. Should I be using AW68?
My question is- In a hydraulic system will the temps rise due to the heavy weight of an oil or too light?

ie; Light weight oil causing leakage/bypass friction from shearing, or heavy oil causing friction due to flow resistance?

I don't have to worry about cold temps, and the summer temps are in the high 80's or low 90's max. Very moderate temps here in the PNW.

 

[walterjay]

I can't speak to the issue of what oil to use, but have you made sure that the oil cooler and radiator are completely clean? I have seen equipment overheat due to dirty cooling fins.

 

[double vanos]

Can't say I've got an answer for you but

Take your seat in the asylum...

 

[WyrTwister]

Doubt if relevant , but I worked at a foundry in the 1970's that had a bobcat front end loader . It used Dexron ATF for hydraulic fluid .

Can you get / do you have a factory manual for it ?

I like the idea of checking the oil cooler , radiator and fan .

 

[A_Harman]

How hot is the oil getting?

 

[Sniffy]

The oil slowly will climb the gauge so when it gets too high i go for an extended coffee break. Having a background in the auto industry I have been minding the rad/cooler cleanliness and keeping the fins straight with an AC comb. Not much of a change in the problem.
From the manual (which comes in half French- randomly placed- over the important stuff)

"If (bobcat) fluid is not available, use 10w30 or 10w40 SAE Motor oil (5w-30 for 0*F [-18*C] and Below).
Do not use automatic transmission fluids in the Versahandler or permanent damage to the transmission will result."

Currently I have AW46 in it.

 

[Sniffy]

According to this chart I should be using AW100 ?

 

[Sniffy]

"Take your seat in the asylum..."

Thanks, but if you knew this machine you would realize that you're in MY asylum now.....