If the transmission oil leaks out of left side half shaft area, it may be from a worn axle shaft seal. The seal can be damaged by a poor surface finish on the axle shaft. The axle shaft and seal should be replaced to correct the problem.
Car Problem Reports
Mercury Mariner Transmission Oil Leaks from Left Side Half Shaft Area
Mercury Mariner Problem
Drive Trains Affected: 2WD, 4WD
Average Mileage: 42,010 mi (11,000 mi - 80,000 mi)
Visitor, 2009 Mercury Mariner, 4WD, 21,753 mi
Transmission fluid was leaking from driver side axle shaft. Ford replaced this part and corrected the problem. My local Gurnee, IL ford was thorough.
Visitor, 2010 Mercury Mariner, 47,000 mi
leakage of transmission fluid on left side, axle leakage
Visitor, 2009 Mercury Mariner, 2WD, 72,000 mi
Car started slipping in gears on take off and i checked fluid and it was low. I took it to a transmission shop and he said i am losing fluid on the left side shaft area. I just bought my Mariner in November of 2011 it was a lease turn in. I love it but i cant believe i am having mechanical problems already.
Visitor, 2009 Mercury Mariner, 4WD, 51,000 mi
axle seal replaced and lasted less than 2 months. Going back to dealer tomorrow for more repairs, possibly replacing axle assembly.
Visitor, 2010 Mercury Mariner, 40,172 mi
bought car used, put a total of 400 miles on in 5 months, last oil change 5 weeks ago, noticed oil on garage floor, mechanic said it was a possible transmission axle seal leak, what a freakin bummer, dont want the car now.
Visitor, 2009 Mercury Mariner, 4WD, 24,299 mi
Noticed fluid dripping. Discovered where axile drive shaft slides into differential. Calling Ford dealer to get repaired had 6 year warranty maybe close running out of warranty.
Visitor, 2009 Mercury Mariner, 2WD, 80,000 mi
I have the same problem. Axle shaft seal leaking left front side. Alot of play.
Visitor, 2009 Mercury Mariner, 2WD, 74,900 mi
Purchased car used from a local Ford dealership and the next day my mechanic noticed the axle seal leaking. Ford dealership confirmed they had just replaced it 200 miles earlier, but in the meantime (1/26/12) Ford issued a service bulletin on this and Ford paid for a proper repair (basically a new left axle). If you've already paid for this repair it might be worth asking Ford for a refund as they've recognized it as vehicle flaw in the manufacturing. Good luck to all!
Visitor, 2009 Mercury Mariner, 2WD, 49,000 mi
transmission fluid leaking from the axle seal on the left side--replaced axle seal but said it was not covered by the drivetran warranty
Visitor, 2009 Mercury Mariner, 2WD, 18,000 mi
The dealer says the parts are on back order.