I have a '98 Cherokee XJ with a 5-speed tranny that has seen extensive beach use here on Long Island. Since the day I purchased it used in 2001, the tranny has consumed about 6oz of tranny oil every 1,200 miles or so. I don't see any sweating on the tranny housing or drops on the driveway.

In the last few weeks, the consumption has jumped to about 6oz in 300 miles! Still no signs of leaks. Also, I have begun hearing a low frequency throbbing sound, loudest at 35mph, which seems to be coming from the rear of the vehicle.

Any thought as to what might be going on here?

Mike

 

You certainly have a leak. Output shaft leak will fill up the void where it mates to the transfer case, input shaft leak will dump it on the clutch and if its slow enough may get spun and spread around that you wouldn't notice it.