• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Drivetrain Rear Pinion Seal Leaking Nut Was Loose

  • Thread starter Thread starter stang89bidges
  • Start date Start date Apr 27, 2014

stang89bidges

Advanced Member
Mar 14, 2014
727
144
74
Fort Worth Texas
Apr 27, 2014
#1
  • Apr 27, 2014
  • #1
Guys I got my drive shaft off after finding a leaking rear pinion seal(so i thought). When I went to take the nut off it just turned.... No force needed. Could have turned it with my hand most likely.

I took it to dyno shop 1.5 years ago. He noticed it was leaking then. But since I had the car I never saw a leak in the driveway. I put a ton of miles on the car in a year. Highway driving. So I never worried about it. Well I had that car up on ramps working on the front end for about 2 straight weeks. I noticed a tiny puddle starting to appear from the rear end. Jacked it up on stands and here I am.

My question. It only looked like it was leaking from the threads. Everything else was bone dry. Do you think the seal is bad or should I just tighted the nut down and call it a day?
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Apr 28, 2014
#2
  • Apr 28, 2014
  • #2
This is from my experience with older cars. While it is that far apart, check where the seal rides for a wear groove, bearing play and replace the seal because it is cheaper now. Use some RTV on the nut going back together.
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
8,914
1,332
204
a van down by the river
Apr 28, 2014
#3
  • Apr 28, 2014
  • #3
if its leaking from the threads, theres fluid getting by the seal, just replace it while your in there. cheap insurance to aoid having to tear it apart again in the near future
 

84Ttop

They make new pistons every day, so why worry?
5 Year Member
Jul 2, 2009
5,222
3,254
204
South Jersey
Apr 28, 2014
#4
  • Apr 28, 2014
  • #4
I'm lazy... Tighten that sucker up and rock and roll!
 

stang89bidges

Advanced Member
Mar 14, 2014
727
144
74
Fort Worth Texas
Apr 28, 2014
#5
  • Apr 28, 2014
  • #5
Yeah I went ahead and pulled the seal. I almost tightened her back up(locked cocked and ready to rock)!

Buuuuuuuttt. I went for a new seal. I just hope I can judge the correct tension on the nut so that I don't go over or under on the crush bearing!
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
8,914
1,332
204
a van down by the river
Apr 28, 2014
#6
  • Apr 28, 2014
  • #6
You should be able to.
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
8,914
1,332
204
a van down by the river
Apr 28, 2014
#7
  • Apr 28, 2014
  • #7
If its a parts store piece, make sure its got the thread locker coating on it or use some to keep it from backing off
 

stang89bidges

Advanced Member
Mar 14, 2014
727
144
74
Fort Worth Texas
Apr 28, 2014
#8
  • Apr 28, 2014
  • #8
Is there a feel to the crush bearing and putting the nut back on? Something I should listen for, feel for, or etc?

As I backed it off I marked the wrong thing.... But I did count how many turns I made. But without marking the nut properly I actually counted cranks with the socket wrench. So I counted 50 cranks. I think I got 3 cranks per full rotation. So about 16-17 turns. I hope this logic works...
 

stang89bidges

Advanced Member
Mar 14, 2014
727
144
74
Fort Worth Texas
Apr 28, 2014
#9
  • Apr 28, 2014
  • #9
I watched this video too late...
View: http://www.youtube.com/watch?feature=player_embedded&v=pCy0Xdz6SNI
 
Reactions: Black GT

stang89bidges

Advanced Member
Mar 14, 2014
727
144
74
Fort Worth Texas
Apr 30, 2014
#10
  • Apr 30, 2014
  • #10
So I put my new seal in. Got the nut on and started to tighten. The amount of revolutions was wrong. The flange was still loose and rocked. So I started to tight further till is stopped rocking. Well. I had to tight the nut all the way until it stopped(as in it was a pretty easy loose turning with the wrench and then all of a sudden it stopped turning). At that point the flange was tight enough it stopped rocking and seemed to be solid again.

Did I go too far with the nut or did I get it right? I didn't tug on it real hard. Just snugged it with the socket wrench a little.
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
8,914
1,332
204
a van down by the river
Apr 30, 2014
#11
  • Apr 30, 2014
  • #11
should be safe. You have to REALLY crank on them to crush that sleeve, sounds like you're right up against it.
 

stang89bidges

Advanced Member
Mar 14, 2014
727
144
74
Fort Worth Texas
Apr 30, 2014
#12
  • Apr 30, 2014
  • #12
Saaweet! Hearing you say that makes me feel better bout it. I sprung for the Mobile 1 with FM built in so I didn't want to lose that $40 worth of fluid because I tightened a nut down too far... One of the reasons I love stangnet!
 

stang89bidges

Advanced Member
Mar 14, 2014
727
144
74
Fort Worth Texas
Jun 17, 2014
#13
  • Jun 17, 2014
  • #13
Update. I drove the car about 100 miles so far after the rear end went back on and no problems so far!
 
You must log in or register to reply here.

Similar threads

O
8.8 Pinion Nut Leak
  • OX1
  • Jan 3, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
804
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jan 5, 2026
OX1
O
S
Drivetrain 8.8 Pinion and 302 rear main seal leaks after replacing. 93 5.0 with t-5
  • Steigy4827
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
10
Views
668
Fox 5.0 Mustang Tech Apr 1, 2026
Steigy4827
S
J
2004 Mustang 3.8L V6 vibrations above 65 MPH and differential leaks
  • joeybuddy96
  • Mar 16, 2026
  • SN95 V6 Mustang Tech
Replies
16
Views
588
SN95 V6 Mustang Tech Jul 14, 2026
joeybuddy96
J
O
Progress Thread LTD-ing
  • OX1
  • Mar 15, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
8
Views
384
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 6, 2026
OX1
O
Water leak from hatchback door
  • jeremyzcook82
  • Nov 24, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
4
Views
197
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Nov 25, 2025
jeremyzcook82
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?