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Otis

Rear leak - pinion seal or axle vent

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I've had a minor leak at the rear differential that was present before I lowered my mustang (1" drop). Originally brought it to dealer for axle vent TSB. Continued to have minor leak. Dealer later stated I had pinion seal leak and replaced seal. Now I'm leaking worse. It's not bad, but enough that over time I'm getting a small puddle under the differential in the garage. I slid under the car today and apparently the dealer never put the turkey baster on the axle vent for the TSB. What I'm wondering is if the extra leaking after the pinion seal replacement is due to overfilling and excess fluid venting as I drive, or is my pinion seal worse off after the dealer replaced it? Anyone have experience diagnosing this? In the pic of the pinion seal area I would expect more dripping and fluid on the yoke where the driveshaft meets the differential if the seal was leaking. Thanks for any input before I head back to the dealer. post-956-139789200134_thumb.jpgpost-956-139789201956_thumb.jpg

Edit: 1st pic is the axle vent. Pics are a little blurry but hope they help.

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The dealer screwed something up IMO. I had my gears replaced, and the drive line shop told me that they wait over an hour for the silicon bead to dry, then they fill & verify no leaks. I've not had any, and they've done so twice, after I had them replace my fluid some time back.

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Yeah I agree. My 1/2 educated guess is the axle vent is still leaking. Hoping someone who's seen a pinion seal leak can confirm one way or the other. I don't want the dealer messing with the differential if they don't need to.

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Your photos are too close in to diagnose a pinion leak.

I slid my phone under the car for the pics (no lift). What area should I take a photo of to be more useful? Thanks

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How's this photo. Dealer did repair a pinion leak earlier and did not clean up the underside. If pinion leak was slinging oil would the yoke between the driveshaft and differential be wet/dripping? I'll try cleaning up the underside and recheck. Thankspost-956-139803241592_thumb.jpg

 

 

3.7 MCA PP

Steeda 91 tune, Steeda CAI, BBK TB, GT500 AB, BMR springs, Koni STR.T

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I had this problem too. for me it was definitely the axle vent. although they didn't put that turkey thing on mine, I do think they stopped the leak. sometimes I don't think its so much a leak as it was imply filled too much. I'll check it again when install the LCA's

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I looked at the TSB for 13+ cars and I think it's mainly checking the fill level. I think the turkey baster touched the exhaust tubing and melted on the 13+. After cleaning up all the oil it looks like my residual dripping was also overfilling. Keeping an eye on the pinion and axle seals just in case.

 

 

3.7 MCA PP

Steeda 91 tune, Steeda CAI, BBK TB, GT500 AB, BMR springs, Koni STR.T

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Here you go. Seems to work from what I've heard on the 11-12's. Also seen 13+ cars use it with some modification to pull the top away from the over axle pipe so it doesn't melt. post-956-139969670747_thumb.jpg

 

 

3.7 MCA PP

Steeda 91 tune, Steeda CAI, BBK TB, GT500 AB, BMR springs, Koni STR.T

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To diagnose a pinion seal leak you need to look directly above the pinion seal on the bottom of the floorpan. The axle vent can't throw oil up there but the pinion seal leak will. Also, when the companion shaft was out was it inspected for wear where the pinion seal rides?

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Welcome to the forum! In the top right section you can click on the "View New Content" button and all the threads will be posted in order by most recent.

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Wow, this forum is dead. I just replied to a 3 1/2 year old thread. Where is everybody?

I love this place, but, yes. It's a little, uh, slow these days. It was never the largest forum, but it has a good core group of members who know their stuff. Less drama that way too .

 

 

Sent from my iPhone using Tapatalk

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