20 Expedition Limited 2WD Differential Leak

[genourumov]

Hey all, first time posting here after just joining. I have a 2020 Expedition Limited trim, 2WD, non extended version. Separate issue to highlight is the shifting from park to reverse or drive can sometimes jerk pretty hard. I haven't noticed a pattern on warm up, if the engine/transmission are already at operating temp or cold/hot day but yeah.

Anyway, maybe related maybe not. The real reason for this post is an obvious leak on the rear differential. The leak appears to be coming from where the drive shaft links up to the differential. I bought this sucker used at about 72K miles. Runs okay otherwise but definitely want to have this fixed before it poses a bigger problem. In my picture you can see this plastic seal has 'popped' out. I tried fooling around with it and 'pressing' back into place with a couple different flatheads but it pops itself back out. Wondering if anyone else has encountered this and how they went about it. Should I drop the drive shaft and try tapping it back into place? Should I try multiple wedges until it goes back in, pull the wedges and see if stays in place? Would it be more appropriate to go full repair with it? Meaning, drop the entire differential, drain, buy a new seal/part as needed, refill with new fluid then remount everything? I have no idea how much may have leaked out and/or if it's been exposed to much water in the past. As mentioned, it drives okay otherwise currently.

The red area is where I was attempting to insert a flathead in an effort to push it back into the differential.

 

[genourumov]

Guess it's the pinion seal...

 

[99WhiteC5Coupe]

On a different vehicle I owned (a Dodge Durango SLT 4x4) - the rear differential leaked at that point.

The dealer repaired it under the power train warranty and I recall being told there was a specific tool to seat the new seal (and perhaps apply a specific amount of pressure)? It was a pinion seal.

I would replace the pinion seal according to the Ford recommendation (special tool?). I would also drain and refill the differential after the repair.

Maybe someone else will chime in with the exact replacement procedure or if a special tool is needed?

 

[Soliyou]

Yeah, that’s the pinion seal. This is a tough one and it has to be done professionally. The torque on that flange is very critical and there are single use components that should be changed when the nut is removed to change the seal.

Some technicians count the number of threads sticking out, change the seal, then torque the nut back to the original position. The video below will show you the process. Also you may have pressure building up in the differential due to a clogged breather. That is a main reason for blowing the seals.

Pinion seal replacement