Brake Retarder

[daVilla208]

I have 2008 Fleetwood Discovery 40. 350 Cummins, with 6 speed Allison transmission.

When desending a mountain, is it o.k. to leave the brake retarder on all the time?
Or, should it be turn off periodically?
Will the engine, or transmission, get hurt if I leave the retarder on all the time as i desend a mountain, or high location.
I was told that the engine does not receive any lubrication, while the retarder is on. So therefore, turn it off after a short use...

[Grizlyadams]

The engine is lubricated all the time it's running.

https://rvlife.com/tips-driving-an-r...untain-grades/

[Gary RVRoamer]

Leave it on unless there is a specific reason to turn it off, like slippery conditions or rolling terrain where coasting makes more sense than braking every few seconds. Whoever told you the engine doesn't get lubricated is full of baloney (or something). The engine is idling when going downhill with the exhaust brake retarding, but an idling engine still pumps oil and stays lubricated.