[Ydna]

I have a 1997 VF2 with 10krpm and gearbox option. Occasionally (every other month of so) I've heard a weird rumbling sound during power up, which *I think* happens during the low/high gearchange. It's hard to tell when the sound occurs since the power up sequence happens so fast, it's either the high gear gearchange or the Z axis homing.

The machine runs fine, it never replicates the sounds except for the power up which is what makes me wonder if it's something else (Z axis). Anyway, I climbed up onto the mill to see if there was anything obviously wrong from the outside. I noticed there's a radiator for the gearbox oil up there, with hoses leading to/from solenoids and the spindle mount.

We're going to remove the covering sheet metal this week to investigate a little further, but I wanted to post a picture of the radiator in case somebody here knows how this thing works. (I'm not familiar with the gearbox hardware). Is it normal for one side of the radiator to appear virtually empty of oil? I'm wondering if this means there's a blockage in there or something.

Thoughts?

[Kool Parts]

I have never had a gearbox machine..but if that pump is running in the picture, that doesn't look right.
Pump not pumping or restriction in the cooler.
Gary

[Ydna]

Yeah I'm not sure if it's just how the system works, or if it means there's a big problem in there (lol). I have a bucket of the DTE 25 sitting around so I could do an oilchange but it'd be nice to know it won't make things worse.

[Ydna]

Update - the oil needed to be changed so we emptied it and realized both of the hoses were actually full and nothing was blocked. Nearest as I can tell the hoses were simply different colors, probably from one of them being replaced.

Just in case anybody is searching for information, the hose nearest to the fill cap is the inlet to the radiator, and the one further away from the fill cap is the outlet. When you run the spindle it circulates fluid through it which we could see (assuming the hoses are clear).
Here's the oil path...
Transmission outlet (bottom of trans) > oil circulatory pump > filter > radiator > transmission inlet (top of trans)