Shop Products
Houzz Logo Print
exmar

hydro oil, confusion

Hi folks,

I've got a Roper LTH 120AR which is either a '82 or '88 with a hydro. It has a drain plug for the hydro and I drain and replace the fluid periodically.

The confusion comes in as the recomended oil is SAE20W, however if that is not available "IT IS PERMISSABLE TO USE A MULTIGRADE VISCOSITY OIL WITH 20 DESIGNATED AS THE LOWEST GRADE. Around here that ends up being 20W50 and the unit works fine.

From the little I know about the mulit vis oils, the lower number only comes into play at ambient temperature. As the the operatiing temperature goes up, so does the viscosity. The trans has cooling fins and a fan so obviiously it runs warm to hot. The unit therefore was designed to run on 20W when it's hot, but is happy with 50W?

Not looking to fix something that ain't broke, just curious about the seeming contradictiion there. Anyone else running old hydros with this issue?

Thanks for your time,

Ev

Comments (6)

Sponsored
EA Home Design
Average rating: 5 out of 5 stars69 Reviews
Loudoun County's Trusted Kitchen & Bath Designers | Best of Houzz