My car is one in a "million", and not in a good way

[shatz]

Well, come to find out my oil pan is leaking from the left side where the front differential meets. Chevy said they have never seen this problem before and someone has a one in a million chance of this happening. I looked up the total time to replace the oil pan on All Data and is said it would take around 4 hrs, Chevy's telling me 2 days:no: .....I'm worried about having it done b/c a)noone in that shop has done it before b)even though they don't have to drop the engine, I still think they will forget to put something back together............Anyone else had this problem or heard of it?:confused:

[bmm354]

Are they sure it's the oil pan that's leaking and not the front diff? The front diff. pinion seal started leaking on my Envoy around 55K miles, and it was hard to tell where it was leaking from at first. A coworker of mine had the same seal problem with his '02 Bravada.

I assume the dealer techs know what they're doing, but if they have any doubt as to where the leak is, they should be willing to add some UV-activated dye to the engine oil (it doesn't hurt anything). This way you can come back in a few days and if the leak glows under UV light then there's no doubt it's engine oil; if it doesn't glow it's likely the diff is leaking.

[Envoy Fan]

Maybe talk to another Chevy dealer in your area:undecided

[Blulytes]

I would be careful when they start saying that they have never seen this problem before.
Its not a year one vehicle... get a second opinion if available.

[shatz]

Well my boyfriend is a mercedes tech who noticed it first, then we took it in and they put in the dye and it was the oil pan.......My bf thinks it is "porous" don't spell check me on that one. He thinks the pan wasn't formed right when it was made....I don't really want to take the tb in, but I don't want anything to happen to my truck either.........

[MA Trailblazer]

My 2005 TB had the same problem and this fixed it. Tell you dealer about this BEFORE they tear it apart.

John


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Lubricant/Oil Leak from Front Area of Vehicle (Install Washer/Shim Between Oil Pan and Front Axle Housing Assembly) #04-04-19-002 - (Nov 18, 2004)
Lubricant/Oil Leak From Front Area of Vehicle (Install Washer/Shim Between Oil Pan and Front Axle Housing Assembly)
2004-2005 Buick Rainier

2004-2005 Chevrolet TrailBlazer, TrailBlazer EXT

2004-2005 GMC Envoy, Envoy XL, Envoy XUV

with 4.2L L6 Engine (VIN S -- RPO LL8) and Four Wheel or All Wheel Drive

Condition
Some customers may comment on an oil leak from the front area of the vehicle.

Diagnosis may show the area of concern is at the axle case/housing half sealing surface adjacent to the pinion seal.

Cause
The front axle case/housing and the engine oil pan are mounted to each other on these vehicles. Casting variations in both the oil pan and the axle case/housing may cause hard contact between these two items where contact is not intended. When this happens, the front axle case/housing may distort when tightened to the oil pan. This may cause a leak path between the front axle case halves.

Correction
Follow the service procedure below to repair this condition.

Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information (SI Document ID #744862).
Diagnose the source of the leak. Refer to Front Axle Lubricant Leak Diagnosis (SI Document ID #700713). • If the source of the leak is something other than the case/housing half sealing surface, continue with the appropriate SI procedure to repair the leak source.
• If the source of the leak is the case/housing halves, continue with the next step.

Important: Observe the position of all the driveline components. Accurately mark the relationship of the components before removal. These components include the propeller shafts, the drive axles, the pinion flanges, and the output shafts. Reassemble all components in the exact relationship to each other as they were before removal. Follow the specifications, the torque values, and any measurements obtained prior to disassembly.


Reference mark the relationship of the propeller shaft to the front axle pinion yoke.
Remove the yoke retainer bolts and yoke retainers from the front axle pinion yoke.
Notice: When removing the propeller shaft, do not attempt to remove the shaft by pounding on the yoke ears or using a tool between the yoke and the universal joint. If the propeller shaft is removed by using such means, the injection joints may fracture and lead to premature failure of the joint.

Disconnect the propeller shaft from the front axle pinon yoke. Wrap the bearing caps with tape in order to prevent the loss of bearing rollers.
Position the front of the driveshaft so that the rear most front axle case/housing bolt can be removed.
Remove the rear most front axle case/housing to oil pan bolt. Upon removal of the bolt, a gap my appear between the front axle case/housing and the oil pan. This may indicate a interference condition between the front axle case/housing and the oil pan.
Loosen the next two forward axle mounting bolts in order to gain proper clearance.



Important: ONLY install ONE washer/shim in the most rearward mounting position as shown above.


Install one washer/shim, P/N 2436165 between the front axle case/housing and the oil pan at the rear most mounting hole as shown above.
Install the front axle to oil pan bolt.

Tighten

Tighten the three front drive axle mounting bolts to 85 N·m (63 lb ft).

Clean the underside of the vehicle with appropriate cleaner.
Remove the tape from the front driveshaft bearing caps.
Align the reference marks made during removal.
Install the propeller shaft to the front axle pinion yoke.
Install the yoke retainers and the bolts.

Tighten

Tighten the front propeller shaft yoke clamp bolts to 20 N·m (15 lb ft).

Remove the front axle oil fill plug.
Fill the front drive axle with the proper fluid SAE 75W-90 Synthetic Axle Lubricant, P/N 89021677 (Canadian P/N 89021678) or equivalent, meeting GM Specification 9986115.

Specification

The oil level should be between 0-13 mm (0-0.5 in) below the fill plug opening.

Install the front axle oil fill plug.

Tighten

Tighten the fill plug to 32 N·m (24 lb ft).

Lower the vehicle.
Parts Information
Part Number
Description
Qty

2436165
Washer/Spacer
1

89021677

(in Canada use 89021678)
SAE 75W-90 Synthetic Axle Lubricant
1


Parts are currently available from GMSPO.

Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

F9703
Washer/Spacer, Frt Axle to Oil Pan - Install
0.6 hr

[shatz]

Thanks for that post, but my tb is 2wd and the oil pan is pre tapped for 4wd.....that's what I'm being told. They ran the tap in to deep and actually punctured the oil pan. I'm going to try and get some pics of it tomorrow, before I take the truck in Tues. Thanks for everyone's help, I just wanted to give you heads up just incase this happens to anyone.