Auto gearbox

[123-jn]

Hi Folks, My ATF is distinctly brown and smells rather like hypoid (although it is runnier.) Do you think someone has topped up the wrong oil before I bought her? or is there a way for final drive oil to get into the autobox and contaminate the atf? Is anyone an expert? The gearbox runs and works fine!!!
help!!!

[R0B]

The two fluids can mix.The seal between the two boxes gives up the ghost,the reason I know is because it happened to mine not long ago.Luckily I had a spare box.I would check the final drive fluid level,if its ok I would replace the ATF.

[123-jn]

thanks Rob I'll check that out.

[billy739]

try draining the g/box oil , flush , clean the filter and refill.

see how you get on , it can mix as stated but not too common , more likely like you said wrong oil used!

you can change the diff oil too , see if both have mixed. the diff oil is based on filled for life tho

[123-jn]

Drained the oil from the auto box, refilled 2.5 ltrs of ATF then ran engine and selected all gears for about 40 seconds, just long enough for the pump to flush the old oil out of the TC. I then drained it again and filled up with another 2.5 ltrs on ATF. I reckon most of the rough stuff is now out and the oil looks nice and red on the stick. I think it changes smoother as well. The final drive was low but I think most of that has exited past the drive shaft seals!! There was a slight burnt smell to the Atf that came out so I'm hoping the box is ok!!!