Leak from tail shaft after 2 new seals

F

Fox123

New Member

Aug 6, 2026

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Al

Aug 6, 2026

#1

• Aug 6, 2026

• #1

Alright I need some help I have put 2 new seals on this and I noticed this the last time I changed it do yall think this can make it leak

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

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Aug 7, 2026

#2

• Aug 7, 2026

• #2

Use some RTV like this one:

Automatic Transmission RTV Gasket Maker, 3 OZ | Permatex®

ATF-resistant RTV for transmission pans and differential covers. Sensor-safe. OEM-approved formula.

www.permatex.com

If that doesn’t work it may take a new tail housing.

 

F

Fox123

New Member

Aug 6, 2026

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Al

Aug 7, 2026

#3

• Aug 7, 2026

• #3

I have already tried that thank you for responding

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

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Aug 7, 2026

#4

• Aug 7, 2026

• #4

That absolutely would make it leak.

Is any part of that gouge proud? If it's lifted about the surface than that will not let it seal properly. You might have to try and file it down slightly, and then maybe fill in the gouge with JB weld and sand it flush.

Hard to do on the trans unfortunately. Might have to pull the extension housing to repair it or replace it.

 

General karthief

wonder how much it would cost to ship you a pair

Mod Dude

Aug 25, 2016

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#5

• Aug 7, 2026

• #5

Some driveshaft seals have a vent/weep hole that needs to go at the top
Just saying

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

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#6

• Aug 7, 2026

• #6

https://lmr.com/item/LRS-4676B/mustang-8-8-pinion-seal-kit-86-14

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

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#7

• Aug 7, 2026

• #7

Noobz...this is the tail housing to drive shaft yolk seal on a transmission so what's up with the pinion seal link?

 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Admin Dude

Jan 4, 1985

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#8

• Aug 7, 2026

• #8

Oops... Wrong end.

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

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Aug 7, 2026

#9

• Aug 7, 2026

• #9

And if you didn’t already have a schnazzy CT…

 

Reactions: General karthief and Noobz347

General karthief

wonder how much it would cost to ship you a pair

Mod Dude

Aug 25, 2016

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#10

• Aug 8, 2026

• #10

AeroCoupe said:

And if you didn’t already have a schnazzy CT…

Click to expand...

If you had the 'powers' you'd change it

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

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Aug 8, 2026

#11

• Aug 8, 2026

• #11

100% I would.

 

Reactions: LILCBRA and General karthief

Blackhawkxx

Mustang Master

Mar 3, 2023

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#12

• Aug 8, 2026

• #12

If a seal for most any rotating shaft keeps going bad and there no defect (rough spot or worn grove) in your case the driveshaft yoke, then it is usually a bad bearing letting the shaft move so much it damages the seal. Saying that, I don't remember what is in the trans rear housing.

 

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keel

Active Member

Aug 23, 2020

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Aug 8, 2026

#13

• Aug 8, 2026

• #13

Blackhawkxx said:

If a seal for most any rotating shaft keeps going bad and there no defect (rough spot or worn grove) in your case the driveshaft yoke, then it is usually a bad bearing letting the shaft move so much it damages the seal. Saying that, I don't remember what is in the trans rear housing.

Click to expand...

Yes that is true a bad tail shaft bushing can cause leaks.

 

Reactions: JD1964

JD1964

there is enough sticking out to grab on to

15 Year Member

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#14

• Aug 9, 2026

• #14

I dont see why RTV wouldnt fix that. However, you need to clean it thoroughly first with brake cleaner and make sure trans fluid cant seep onto the area. Apply sealer, install seal. Heres the important part. You gotta wait for the sealer to fully cure before you put trans fluid back in. If its warm enough out, thats at least 24 hours. Maybe longer if colder out