I have a 2002 jeep liberty. Its a 2wd but the rear diff is spitting fluid out the vent tube. What could the problem be? needs to be serviced or the vent tube check valve need replacing? it has 140,000 miles and never been serviced. any info would be great.

 

I want to bring this back up, any ideas why it would do this?

First time I changed fluid and it stopped, not its doing it again after fresh fluid.

any ideas?