Sponsored

Halfshaft leaking at diff case

OneFordGT

Well-Known Member
Joined
Mar 21, 2016
Threads
3
Messages
213
Reaction score
71
Location
Ohio
Vehicle(s)
16 GT
Hey guys, had my car on the lift today changing the engine oil and noticed that my drivers side halfshaft seems to have a slow leak that's running down the side of the diff case. It's just enough oil to make the case wet about 2 inches in diameter below where the shaft goes into the case. It's only on the drivers side. I recently switched the diff fluid to BG. I followed the directions on how much fluid to put in and how to measure it, but would this would this be caused from over filling? I did a search and couldn't find where anyone else had this problem.
Sponsored

 
Last edited:

EXP Jawa

Well-Known Member
Joined
Jun 9, 2014
Threads
3
Messages
1,011
Reaction score
205
Location
Rochester, NY
Website
www.torsen.com
First Name
Rick
Vehicle(s)
1999 Cobra Convertible, Electric Green
It could be over filling. But you should also be aware that - in theory - the oil seals are optimized for the lube that Ford used, and changing it could impact the seals. how likely that is or to what extent is anyone's guess, but the Ford dealer could well tell you that's the cause and effect if you take it in as a warranty claim.
 

IvanCRF

Well-Known Member
Joined
Feb 19, 2015
Threads
9
Messages
1,172
Reaction score
350
Location
El Paso, Texas
Vehicle(s)
5.On'ry
Is this the stock halfshaft? I ask because when installing new ones into the diff, you need to ensure the ring "clicks" into place to ensure the halfshaft is fully seated.
 

GTBOB

Well-Known Member
Joined
May 27, 2015
Threads
37
Messages
1,304
Reaction score
619
Location
Fairfield Township, OHIO
First Name
Bob
Vehicle(s)
'18 GT, Royal Crimson, 10 speed, Active Exhaust
Vehicle Showcase
1
Is there a breather tube on top of our diffs? If so, make sure it is not pinched or kinked to relieve internal pressure.
 
OP
OP
OneFordGT

OneFordGT

Well-Known Member
Joined
Mar 21, 2016
Threads
3
Messages
213
Reaction score
71
Location
Ohio
Vehicle(s)
16 GT
Is this the stock halfshaft? I ask because when installing new ones into the diff, you need to ensure the ring "clicks" into place to ensure the halfshaft is fully seated.
Yes, stock shafts. I have about 5,500 miles on the car. No power adder. Since changing the diff fluid I have driven about 300 highway miles. I didn't see the leak before.

Is there a vent on these diffs? I'm guessing there was a lot of bubbles and air in the fluid when I pumped it in and it didn't have time to escape before I re-installed the fill plug and maybe the positive pressure pushed some oil out of the halfshaft seal?
 

Sponsored

OP
OP
OneFordGT

OneFordGT

Well-Known Member
Joined
Mar 21, 2016
Threads
3
Messages
213
Reaction score
71
Location
Ohio
Vehicle(s)
16 GT
Is there a breather tube on top of our diffs? If so, make sure it is not pinched or kinked to relieve internal pressure.
I'll check tomorrow when I get the car back up on the lift. That's kind of what I was thinking. If there is I'll make sure it's not pinched and clean the oil up around it, then re-check for leaks after a few hundred miles.
 

wildcatgoal

@sirboom_photography
Joined
Feb 8, 2016
Threads
76
Messages
6,589
Reaction score
2,500
Location
USA
Vehicle(s)
TBD
I have BG fluid + Ford Friction modifier (BG didn't cut it alone for my Torsen) and I have no leaks. Don't think it's the BG fluid unless overfilled. You don't fill these diffs (at least mine) until it comes out of the fill hole.
 

IvanCRF

Well-Known Member
Joined
Feb 19, 2015
Threads
9
Messages
1,172
Reaction score
350
Location
El Paso, Texas
Vehicle(s)
5.On'ry
Is there a breather tube on top of our diffs?
Yup. It goes from the rear passenger wheel well, down to the top of the cradle with a plastic clip and then to the top part of the diff cover where there's an aluminum barb that is pressed into the cover.
 
OP
OP
OneFordGT

OneFordGT

Well-Known Member
Joined
Mar 21, 2016
Threads
3
Messages
213
Reaction score
71
Location
Ohio
Vehicle(s)
16 GT
*update, I removed the fill plug and rechecked the level of oil in the diff and if you want to split hairs it was maybe 1/3mm over full. Using my eye ball level the car looked to be level Both ways while sitting on the lift. I removed about 1/2 ounce just as a test to see if that helps.
The first three images are the drivers side, the last image is the passenger side. Earlier I reported it was only the drivers side but apparently I didn't look close enough. I saw the vent that IvanCRF pointed out and it was not kinked or impaired as far as I could tell.
My conclusion is that it was too full and since I take corners turning right harder than when turning left that the oil was pushed more that direction and leaked out. I cleaned the wet area up the best I could and will check it in a month or so.

What do you guys think?
IMG_4478.JPG
IMG_4479.JPG
IMG_4480.JPG
IMG_4481.JPG
 
Last edited:

IvanCRF

Well-Known Member
Joined
Feb 19, 2015
Threads
9
Messages
1,172
Reaction score
350
Location
El Paso, Texas
Vehicle(s)
5.On'ry
You might already have this info, but here it is from my manual:

3. Check and top off the differential with clean differential gear lubricant. The differential gear lubricant level
should be within 9mm (0.354 in.) from the fluid level fill plug opening.
Refer to: Specifications (20502
Rear Drive Axle/Differential, Specifications).
Material: Motorcraft® SAE 75W85
Premium Synthetic Hypoid Gear Lubricant / XY75W85QL
(WSSM2C942A)

4. Install the differential fluid fill plug.
Torque: 25 lb.ft (34 Nm)


---------------------------


Analysis of Leakage
Clean up the leaking area enough to identify the exact source.
A plugged Rear axle housing vent can cause excessive pinion seal lip wear due to internal pressure buildup.
Verify the differential lubricant level is at the correct level.
REFER to: Differential Fluid Level Check (20502)
.
Axle Vent
A plugged vent will cause excessive seal lip wear due to internal pressure buildup. If a leak occurs, check the
vent. If the vent cannot be cleared, install a new vent.
Drive Pinion Seal
Leaks at the drive pinion seal originate from the following causes:
Damaged seal
Worn seal journal surface
A new drive pinion flange must be installed if any of these conditions exist.
Any damage to the seal bore (dings, dents, gouges or other imperfections) distorts the seal casing and
allows leakage past the outer edge of the drive pinion seal.
The drive pinion seal can be torn, cut or gouged if it is not installed correctly. The spring that holds the
drive pinion seal against the pinion flange may be knocked out and allow fluid to pass the lip.
Metal chips trapped at the sealing lip can cause oil leaks. These can cause a wear groove on the drive
pinion flange and result in pinion seal wear.
When a seal leak occurs, install a new drive pinion seal and check the vent to make sure it is clean and
free of foreign material.
Differential Seals
NOTICE: When installing shafts, do not allow splines to contact seals during installation or damage to the
seals may occur.
Halfshaft pilot bearing housing seals are susceptible to the same types of damage as drive pinion seals if
incorrectly installed. The seal bore must be clean and the lip handled carefully to avoid cutting or tearing it. The
seal journal surface must be free of nicks, gouges and rough surface texture.
 

Sponsored
OP
OP
OneFordGT

OneFordGT

Well-Known Member
Joined
Mar 21, 2016
Threads
3
Messages
213
Reaction score
71
Location
Ohio
Vehicle(s)
16 GT
You might already have this info, but here it is from my manual:

3. Check and top off the differential with clean differential gear lubricant. The differential gear lubricant level
should be within 9mm (0.354 in.) from the fluid level fill plug opening.
Refer to: Specifications (20502
Rear Drive Axle/Differential, Specifications).
Material: Motorcraft® SAE 75W85
Premium Synthetic Hypoid Gear Lubricant / XY75W85QL
(WSSM2C942A)

4. Install the differential fluid fill plug.
Torque: 25 lb.ft (34 Nm)


---------------------------


Analysis of Leakage
Clean up the leaking area enough to identify the exact source.
A plugged Rear axle housing vent can cause excessive pinion seal lip wear due to internal pressure buildup.
Verify the differential lubricant level is at the correct level.
REFER to: Differential Fluid Level Check (20502)
.
Axle Vent
A plugged vent will cause excessive seal lip wear due to internal pressure buildup. If a leak occurs, check the
vent. If the vent cannot be cleared, install a new vent.
Drive Pinion Seal
Leaks at the drive pinion seal originate from the following causes:
Damaged seal
Worn seal journal surface
A new drive pinion flange must be installed if any of these conditions exist.
Any damage to the seal bore (dings, dents, gouges or other imperfections) distorts the seal casing and
allows leakage past the outer edge of the drive pinion seal.
The drive pinion seal can be torn, cut or gouged if it is not installed correctly. The spring that holds the
drive pinion seal against the pinion flange may be knocked out and allow fluid to pass the lip.
Metal chips trapped at the sealing lip can cause oil leaks. These can cause a wear groove on the drive
pinion flange and result in pinion seal wear.
When a seal leak occurs, install a new drive pinion seal and check the vent to make sure it is clean and
free of foreign material.
Differential Seals
NOTICE: When installing shafts, do not allow splines to contact seals during installation or damage to the
seals may occur.
Halfshaft pilot bearing housing seals are susceptible to the same types of damage as drive pinion seals if
incorrectly installed. The seal bore must be clean and the lip handled carefully to avoid cutting or tearing it. The
seal journal surface must be free of nicks, gouges and rough surface texture.
Thank you for the notes, IvanCRF.

I measured the fill level and it's at the correct amount.

My car is still on the lift so I'm going to see how easily the vent comes off the and try pushing some air through it to see if it plugged. Thanks again for the notes you provided.
 

IvanCRF

Well-Known Member
Joined
Feb 19, 2015
Threads
9
Messages
1,172
Reaction score
350
Location
El Paso, Texas
Vehicle(s)
5.On'ry
The vent hose comes off easily from the barbed end at the diff cover so you can have a person to help blow air through the hose at the wheel well and another person at the diff for verification.

After that, there's a small, thin steel plate that hangs on by a torx screw that covers the barb on the inside and a cast aluminum channel.
 
OP
OP
OneFordGT

OneFordGT

Well-Known Member
Joined
Mar 21, 2016
Threads
3
Messages
213
Reaction score
71
Location
Ohio
Vehicle(s)
16 GT
Took the vent off at the barb and blew air through it, free and clean as a whistle. From now I'll just have to drive it for a bit and then recheck. Thanks for everyone help, I'll keep you all updated.
 

09jsw

Well-Known Member
Joined
Nov 11, 2014
Threads
44
Messages
1,298
Reaction score
280
Location
East coast
Vehicle(s)
2015 Guard PP GT
Mine is leaking the same way and I've never touched the rear. Smh I guess I'll try the dealer
 
 




Top