ZF Transmission Questions

[cenger]

When checking the oil on my ZF Transmissions should they be checked while the engine is running or when the engine is off? When I check them cold oil level is above the high mark, when running its below the low mark. I'm not sure which is correct or if they need to be checked hot and off? I read in some other threads that Alison transmissions use same 40wt as the engines. Is the same true for ZF Transmissions (I use Rotella 40wt in the engines)? Thanks in advance.

 

[osprey]

https://www.sbmar.com/articles/checking-changing-the-oil-on-your-zf-marine-transmission/

 

[racclarkson@gmail.com]

When checking the oil on my ZF Transmissions should they be checked while the engine is running or when the engine is off? When I check them cold oil level is above the high mark, when running its below the low mark. I'm not sure which is correct or if they need to be checked hot and off? I read in some other threads that Alison transmissions use same 40wt as the engines. Is the same true for ZF Transmissions (I use Rotella 40wt in the engines)? Thanks in advance.

The answers are dependent upon which ZF model you’re running. Some take ATF and some take motor oil. My ZF BW 250’s each take about 7-1/2 gallons of 40wt. The manual states the level as between the marks at rest, no mention of time period from stopping. I’ve always run mine just above the full mark cold or hot. Unlike motors, it takes no time for the oil level to stabilize after shutdown, at least on my gears.

 

[SKYCHENEY]

Not sure about the ZF's but most gears are to be checked warm, running, and in neutral to get the proper level.

 

[racclarkson@gmail.com]

Not sure about the ZF's but most gears are to be checked warm, running, and in neutral to get the proper level.

That’s true. But in the case of the ZF’s I run, the manual specifically states to not check while hot or running. Very much brand and model specific it seems.

 

[Pascal]

The manual for my ZF280 states to check level 2 minutes after the engine is shut down. It doesn’t mention it needs to be warm.

Recommends straight 30 or straight 40 when sump temp is over 85F

 

[tkbsurf]

Hi there,

ZF gears should be checked "static", not running. However, they should be warmed up for best accuracy. The reason is the oil from the gearbox is pumped through the cooling circuit while running. This changes with different applications because the heat exchanger could be remote mounted far away from the gearbox. Depending on the volume of oil in the circuit, this could give you a slightly higher reading when cold. You want to make sure you have enough oil to cover the cooling circuit if yours is mounted this way.

What model ZF gearbox?