Yukon Denali. T-Case leak

[Dan2002]

I have a 2002 yukon Denali.

I noticed my front differential leaking from the driver side to my suspension to the ground

I saw the vent tube leaking. This never happened before. Any ideas?

 

[Dan2002]

I have a 2002 yukon Denali.

I noticed my front differential leaking from the driver side to my suspension to the ground

I saw the vent tube leaking. This never happened before. Any ideas?

Cleaned the hose and everything.
Did a diff oil change and drove it about 30 miles at 70MPH and still leaking from the breather hose

 

[afpj]

The breather tube end with the cap needs to be upright. If hose is bent bent and end pointing down, it can leak. Also, I don't know if this applies to Denalis, but my Yukon 4x4 SLE has the original vent cover on the the diff, so it requires DINO oil. Can only use synthetic with the newer vent cover that's white. the original one on 2002's is black. also I think I read that 2004 they changed them all to the newer one to handle synthetic. See TSB below:

Document ID# 1548733


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


Subject: Info - Use of Synthetic Front Axle Lubricant For 4WD Vehicles Sold in Cold Weather Climates #03-04-19-001B - (09/03/2004)

Models: 2002-2004 Chevrolet Avalanche 2500, Silverado 2500/3500, Suburban 2500

2002-2003 Chevrolet Silverado 1500HD

2002-2004 GMC Sierra 2500/3500, Yukon XL 2500

2002-2003 GMC Sierra 1500HD

with Four-Wheel Drive and 9.25" Front Axle Assemblies and Built Prior to April 1, 2004




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

This bulletin is being revised to update vehicle applications, part numbers and fluid fill information. Please discard Corporate Bulletin Number 03-04-19-001A (Section 04 -- Driveline/Axle).

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

Important: This bulletin is intended for vehicles sold in very cold weather climates, especially those in Alaska and certain regions of Canada.
Important: This bulletin DOES NOT apply to vehicles built after April 1, 2004. Vehicles referenced above that were built after April 1, 2004 were manufactured with front axles containing synthetic axle lubricant and do not need to have the front axle fluid inspected or changed.
Front axles in the above-listed vehicles built before April 1, 2004 are manufactured with mineral-oil base axle fluid. Because of the 9.25" front axle assembly's internal design characteristics, there may be insufficient lubrication flow at very low ambient temperatures (-24°C (-12°F) or below). This may contribute to premature pinion bearing wear if a vehicle is driven extensively in very low ambient temperatures.
Important: Please be certain that PDI personnel know to perform the drain/refill procedure all year round (not just in the cold weather months).
New vehicles that are expected to operate extensively in 4WD in temperatures below -24°C (-12°F) should have their front axle fluid drained and refilled with synthetic axle lubricant during PDI or before delivery to the first retail customer.
Follow the Front Drive Axle Lubricant Replacement procedure found in the Service Manual (SI Document ID #673354). It is not necessary to flush the front axle assembly. Use Synthetic Axle Lubricant, P/N 12378261 or P/N 89021677 (Canadian P/N 10953455 or P/N 89021678 ). Each of these part numbers is the same axle lubricant, with differences in packaging only. Fill to a level between 6 and 9 mm (0.25 in to 0.375 in) below the bottom of the fill plug.
For vehicles that have the axle lubricant changed, the front axle vent hose connector assembly will need to be inspected.
Important: Front axle assemblies with a vent hose connector assembly that is white in color do not need to be changed.
If the vent hose connector is black in color, it will need to be changed so that the O-ring seal is compatible with the synthetic lubricant. Install vent connector, P/N 12479390 . Follow the Front Drive Axle Vent Hose Connector Replacement procedure in the Service Manual (SI Document ID #843184).
Parts Information
Part Number Description Qty
12378261 or 89021677
(Canadian P/N 10953455 or 89021678 ) Oil, Synthetic Gear 2
12479390 Connector, Axle Vent 1

Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Description Labor Time
*F0011 Fluid, Axle and Differential (Front) - Drain and Fill 0.5 hr
Add To Replace Front Axle Vent Hose Connector 0.1 hr
*This is a unique labor operation number for use only with this bulletin. This number will not be published in the Labor Time Guide.

 

[Dan2002]

The breather tube end with the cap needs to be upright. If hose is bent bent and end pointing down, it can leak. Also, I don't know if this applies to Denalis, but my Yukon 4x4 SLE has the original vent cover on the the diff, so it requires DINO oil. Can only use synthetic with the newer vent cover that's white. the original one on 2002's is black. also I think I read that 2004 they changed them all to the newer one to handle synthetic. See TSB below:

Document ID# 1548733


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


Subject: Info - Use of Synthetic Front Axle Lubricant For 4WD Vehicles Sold in Cold Weather Climates #03-04-19-001B - (09/03/2004)

Models: 2002-2004 Chevrolet Avalanche 2500, Silverado 2500/3500, Suburban 2500

2002-2003 Chevrolet Silverado 1500HD

2002-2004 GMC Sierra 2500/3500, Yukon XL 2500

2002-2003 GMC Sierra 1500HD

with Four-Wheel Drive and 9.25" Front Axle Assemblies and Built Prior to April 1, 2004




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

This bulletin is being revised to update vehicle applications, part numbers and fluid fill information. Please discard Corporate Bulletin Number 03-04-19-001A (Section 04 -- Driveline/Axle).

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

Important: This bulletin is intended for vehicles sold in very cold weather climates, especially those in Alaska and certain regions of Canada.
Important: This bulletin DOES NOT apply to vehicles built after April 1, 2004. Vehicles referenced above that were built after April 1, 2004 were manufactured with front axles containing synthetic axle lubricant and do not need to have the front axle fluid inspected or changed.
Front axles in the above-listed vehicles built before April 1, 2004 are manufactured with mineral-oil base axle fluid. Because of the 9.25" front axle assembly's internal design characteristics, there may be insufficient lubrication flow at very low ambient temperatures (-24°C (-12°F) or below). This may contribute to premature pinion bearing wear if a vehicle is driven extensively in very low ambient temperatures.
Important: Please be certain that PDI personnel know to perform the drain/refill procedure all year round (not just in the cold weather months).
New vehicles that are expected to operate extensively in 4WD in temperatures below -24°C (-12°F) should have their front axle fluid drained and refilled with synthetic axle lubricant during PDI or before delivery to the first retail customer.
Follow the Front Drive Axle Lubricant Replacement procedure found in the Service Manual (SI Document ID #673354). It is not necessary to flush the front axle assembly. Use Synthetic Axle Lubricant, P/N 12378261 or P/N 89021677 (Canadian P/N 10953455 or P/N 89021678 ). Each of these part numbers is the same axle lubricant, with differences in packaging only. Fill to a level between 6 and 9 mm (0.25 in to 0.375 in) below the bottom of the fill plug.
For vehicles that have the axle lubricant changed, the front axle vent hose connector assembly will need to be inspected.
Important: Front axle assemblies with a vent hose connector assembly that is white in color do not need to be changed.
If the vent hose connector is black in color, it will need to be changed so that the O-ring seal is compatible with the synthetic lubricant. Install vent connector, P/N 12479390 . Follow the Front Drive Axle Vent Hose Connector Replacement procedure in the Service Manual (SI Document ID #843184).
Parts Information
Part Number Description Qty
12378261 or 89021677
(Canadian P/N 10953455 or 89021678 ) Oil, Synthetic Gear 2
12479390 Connector, Axle Vent 1

Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Description Labor Time
*F0011 Fluid, Axle and Differential (Front) - Drain and Fill 0.5 hr
Add To Replace Front Axle Vent Hose Connector 0.1 hr
*This is a unique labor operation number for use only with this bulletin. This number will not be published in the Labor Time Guide.

It was upright the whole time. But I did replaced it with synthetic oil. I will try to get the new vent for it. And see if it helps.

Thank you for the reply

 

[afpj]

Just to clarify, is it leaking at the little end cap of the vent tube, or at the differential screw in vent cap? The TSB I think really is for those that leak at the screw in vent cap area on the diff itself. I may have misinterpreted your original post.

 

[Dan2002]

Just to clarify, is it leaking at the little end cap of the vent tube, or at the differential screw in vent cap? The TSB I think really is for those that leak at the screw in vent cap area on the diff itself. I may have misinterpreted your original post.

Its leaking from the little black end cap on the hose that goes to the front differential. It is attached on the driver fender and it's leaking to my suspension and getting it all over the place

 

[afpj]

Ok got it. Is it still leaking with new oil? If so, is the level correct? Iirc, again may not apply to Denali, but my diff calls for level up to fill hole only when warm. Cold level is like 0.5 in (or something like that)

 

[Dan2002]

Ok got it. Is it still leaking with new oil? If so, is the level correct? Iirc, again may not apply to Denali, but my diff calls for level up to fill hole only when warm. Cold level is like 0.5 in (or something like that)

It is still leaking. And I filled it up untill it came out of the fill hole. Even if I overfilled it a little bit. It should have stopped by now. I been driving it every day for over 60 miles and keeps leaking every time

 

[Rocket Man]

Following. I want to see if it quits leaking after a new vent cap. I changed to synthetic in mine but I don't have this problem.