View Full Version : Leaking differential
So I have about 2000 miles on my mk4, finished the build about six months ago, started late 2018 with all new parts and irs. Have had no leaks of any kind until this week when I see maybe 15 cc of liquid on the floor. Looks like coming from diff on passenger side where the half shaft exits. Tentatively planning to replace that seal. Any other thoughts, suggestions? Any advice on replacing this seal? Did I make a mistake in original assembly? Thanks. Jim
Bob Cowan
12-02-2020, 02:55 PM
It's a pretty easy job. Remove the axle and upright as a unit; it's easier that way. Replace the seal by placing a block of wood over it and tapping it in to place. The block of wood will help it to go in straight.
Buy 2 axle seals, in case you screw up the first one. :)
Railroad
12-02-2020, 03:29 PM
Look at the gap between the drivers side axle hub and the diff case. Compare that gap to what the passenger side looks like. If the passenger side has a larger gap, the axle splines are not completely seated. This keeps the hub from reaching the seal, thus the leak.
Second issue some people have, is over filling the rear diff case. The fill plug is the one near the same level as the axles, not the one high on the case.
Good luck on an easy fix.
wallace18
12-02-2020, 04:50 PM
I have seen the axle come loose out if the car hits a big bump. Check to see if it is all the way in first.
I appreciate all the information very much! I will check the seating before pulling the half-shaft. I’m guessing I should drain some of the fluid before replacing the seal if it comes to that? Should I get the replacement seal from Ford or is any auto parts store ok? Thanks
FFinisher
12-04-2020, 07:36 AM
I have seen the axle come loose out if the car hits a big bump. Check to see if it is all the way in first.
Ditto
Many thanks to Wallace18 and FFinisher, eyeballing the passenger half axel vs the driver side the passenger side had a tiny bit larger gap. Using only my hands it closed up to match the drivers side without any disassembly. I tried to move it back out but it seemed firm. No leaks after a 10 mile drive! I plan to keep a close eye on it. I really appreciate you guys reading these posts and responding with such good advice, I was getting ready to take everything apart and replace that seal. Thanks again!
Oh, thanks to Railroad too!