When changing fluid on ZF 5-speed and ZF 6-speed we are supposed to wait until fluid just trickles before installing drain plug.
I’ve changed fluid four times on these and every time the fluid continues a steady trickle from 30 Celsius thru 50 Celsius (Max temp for fluid change)
As the tranny warms up and the fluid expands, the ‘trickle’ never really slows thru the temp range. A steady small stream continues throughout the temp range.
There’s a fairly large difference in the fluid level at 35 Celsius and letting it trickle until 50 degrees.
Am I good to replace drain plug anywhere in that temperature range?… or should I wait until 50 degrees for proper level?
Thanks for your clarifications!

 

As soon as its just a trickle put the plug in at 35deg

 

At around 30 degrees, just keep pumping the fluid pump and as soon as fluid starts coming back out, remove the pipe from the pump, grab hold of the bung and put it in. By the time you've picked the bung up and manoeuvred it around the hot exhaust, the outflow will have subsided enough. Overfilling slightly is not a problem.

Richard

 

Thank you for the clarification.
I waited until 40 so it may be slightly low but still in range.
Most advice is precise on the forum, but that detail is mostly vague as “wait for the trickle. My ADD insisted I get precision for the future and the forum.
thanks guys!