2L transmission noise

[Nedsbongo]

Hey everyone
I have a 2001 2L bongo that has developed and strange noise. It makes a loud buzzing noise when changing gear or when selecting drive/Neutral/Park. It lasts about 1s every time and sounds like Solenoid. It is louder when the engine is hot and quiet when cold. The transmission works perfectly though doesn’t slip and goes into every gear fine. It was serviced about 3000km ago. Any ideas ??

[g8dhe]

Can't say I have heard of a report like that before ? The gearbox does have a bunch of solenoids that control the oil operated planetary gears, these are replaceable. Might be worth checking oil level in the gearbox, make sure you use the right procedure, engine running and engine & gearbox upt to temperature then whilst engine still running use the gearbox dip stick - its fiddly as the oil splashed around so you may need to do it several times to be sure. Should be a clear pink/red if it smells of burnt toast or is strongly discoloured then it needs draining and refilling. Be aware that its quite difficult to remove all the oil as a large proportion is in the Torque Convertor.

[Nedsbongo]

Right so I wasn’t convinced with the transmission oil color so decided to change it. I managed to suck out 4L and just put 4 back it. Engine was already warm from the drive to get oil. So I started it up and let it idle for 5 min, ran through the gears and it dipped as over full, about 3/4inch over the top mark. So I pumped some out and drove around the block a few time and checked it again. It was just above fill I end up taking about 400ml out??? Does this seem correct, does the torque converter hold that much. Note I didn’t take much notice of the old oil level after seeing the color of it….
No change to my original issue unfortunately

[g8dhe]

Yes the TC holds a lot of oil its what 18" diameter and a at least a 2-3" thick (at a guess). Which is why its difficult to fully drain the gearbox.

torque convertor.jpg (12.47 KiB) Viewed 482 times

[Nedsbongo]

Update, took it for a 3 hour drive to Edinburgh and seems to have resolved itself. Must have been bad atf.