Thread: interesting gearbox behaviour

It won’t lock up until the fluid reaches operating temperature (hence the higher rpm)

I’ve not noted it personally? I don’t notice any different operation in shift point or lockup. Mine’s a bit clunkier when cold in the first to second change by for me that’s the only difference cold to hot.

Originally Posted by Tombie

It won’t lock up until the fluid reaches operating temperature (hence the higher rpm)

Hey Tombie, Yep that was my natural assumption too, however the company that rebuilt the box assures me that they don't believe that the gearbox shouldn't behave like that yet it seems the only rational reason, hence the post. I was just looking for confirmation that was the case.
regards

Yep - seen the same thing and noticed the difference depending on how cold it was to start with. It is most noticeable going straight up to highway speeds.

From my observation the ZF8 does not seem to do this to the same extent. Or maybe our highway speeds are too low to see the effect in the 8?

The ZF8 climbs gears slightly differently when cold...

It doesn’t take long for either box to get warm, and warm is good (over cold) so the boxes just slip via the TC for a little while to warm up.

Originally Posted by NomadicD3

Hi All,
I have a few curiosities about the ZF6 gearboxes. Has anyone else noticed that the gearbox seems to slip a few hundred revs for the first 5-10k’s in the morning?

Interesting - I've had my 8 speed D4 for a couple of months and had noticed that the gearbox seems to "flare" or spin higher revs occasionally, and doesn't seem to have as much torque in lower gears at those times - I'll keep an eye out to see if that's when it's first starting off.