Hello all,

 

I'm looking at buying a 1998 Legacy Outback wagon with about 125K on it. It appears that the front seal on the differential is leaking. How difficult of a chore is this? Special tools? Or is this a job best left to the "professionals"?

Thank you.

The title says "Rear Seal" but in the post you talk about the front seal.

 

It's probably due for a Timing Belt kit anyways so I would start there and get one that includes the cam seals/front oil seals.  Only special tool that some people use is a crank bolt pulley tool to hold the crank still while you pull the bolt.

 

You will need a bunch of mm sockets (make sure you have 8mm up to 22mm in normal size, and then I would get 8mm to 16mm or higher in deepwell as well).

 

Now, if it actually is the rear seal that's a whole different scenario.  Your going to have to at least shift the engine or transmission, if not pull the engine, to do it.

yeah - we neeed a better description of the problem.

 

what type of fluid are you losing? rear diff gear oil (it should be full when it runs out the top, square-socket pluf)

 

if auto trans, is that fluid level good? (must be checked while idling)

 

MT or front diff oil ? check the dipstick on the right side at the firewall.

 

engine oil level?

 

could be the air/oil plate on the back of the engine leaking or ???

Ok, for some reason I didn't see "differential" when I read this.  That is completely different than the engine seals.  

 

As Texan said we need to know what kind of fluid and color even.  Is it Engine Oil, Differential Oil, or ATF?  Each of these oils comes from a different place and if it is anywhere on or near the engine it may or may not be the diff.  It could be engine oil leaking and ending up in that location, it could be ATF from the transmission or power steering pump leaking and ending up there ,etc....

maybe post a pic of the area where you see the oil.

not a common failure - if you want to repair it yourself and avoid the seal replacement, get a used differential and swap it out. 

i have one for your vehicle: $35 + shipping

 

the front nut is a beast.  be sure to mark it if it sets the bearing preload or ring and pinion back lash at all - which i think it does:

mark it's exact location and try to install it in the exact location - same number of turns and same location - make a mark with a grease pen.

 

http://www.ultimatesubaru.org/forum/topic/122731-rear-differential-seal-leak/

 

you can also find the factory service manuals online for free - any 1995 - 1999 FSM for any Subaru will be identical procedure for that part and the torque for the nut.

Thank you all for your input. To clarify, it is the seal where the propellor shaft enters the rear differential. Gear oil is spattered on both sides of the gas tank, which straddles the drive shaft. Is it possible it was overfilled at a Quickie Lube?

 

I think I will procede with the purchase. Timing belts and head gaskets were recently replaced. Car was from Carolina and lacks the saltbelt rust patterns. Gary, I will keep you in mind for that diff if I decide to go that route.

 

Thanks.

very difficult to overfill.

Edited May 12, 201510 yr by 1 Lucky Texan

+1 it can't really be overfilled, the fill plug is where you add fluid.  if you "overfill", it would just come out while you're filling.

+1 it can't really be overfilled, the fill plug is where you add fluid.  if you "overfill", it would just come out while you're filling.

Unless you fill it out of the car, vertically. That was an oops moment

ha ha, right on.  really you did that on purpose?  one could also fill from the breather hole....but none of those ways of filling would be approaches from a quick lube place.

Well, unless someone rolled it on its side in the mud and before rolling it back down decided to add dif fluid.

ha ha, right on.  really you did that on purpose?  one could also fill from the breather hole....but none of those ways of filling would be approaches from a quick lube place.

I had just finished letting it cool from welding it and I figured it'd be easier outside of the car. Up to the top lol. Thankfully came out the rear seal where like the lugs are so I just took it off and siliconed it properly and filled it correctly

This is actually an involved process. You must reset the preload on the pinion bearings correctly after replacing the seal or you'll be pulling that diff again in several hundred miles. Unless you have single digit inch-pound torque wrenches, I'd leave it alone. Look for a shop locally that does diff set-ups or repair work. Save yourself the money and pull it yourself, let them rebuild, then throw it back in. Just remember to mark the flange positions before you separate or you'll be chasing a nasty vibration issue...