Rear main Seal

[lspann3525]

I have a 2008 Tahoe Z71 4WD that has a oil leaking coming from between the engine/transmission. Over the years I have changed the oil pan gasket several times thinking that was the problem but it seem to be the rear main seal. The valve cover gaskets have been changed recently and while doing them I tried checking the valley cover pan but didn't see anything.

So that only leaves me to believe the rear seal is the problem. Ive watched several videos on moving the transmission back to get access. But im kinda discouraged because this is a 4x4 and the transfer case and transmission look huge together. I have a transmission jack that I will be using and maybe a floor jack for the transfer case.

My question is can the transfer case be removed to make it easier for me?? Are there any kind of special seals between the transfer case and transmission that could be damaged during removal.

And also anyone have an easy way of doing this?? I know the exhaust is going to give me hell

 

[donjetman]

I did the rear main seal 4+ yrs and 55k miles ago. No regrets.
https://www.tahoeyukonforum.com/threads/rear-main-seal-job-pan-etc-07-yukon-denali-6-2.108334/
and
https://www.tahoeyukonforum.com/thr...tor-oil-consumption-tsb-10-60-10-008m.108493/
and
https://www.tahoeyukonforum.com/threads/engine-oil-pan-gasket-change-6-2-yukon-l92.108487/

 

[Geotrash]

I have a 2008 Tahoe Z71 4WD that has a oil leaking coming from between the engine/transmission. Over the years I have changed the oil pan gasket several times thinking that was the problem but it seem to be the rear main seal. The valve cover gaskets have been changed recently and while doing them I tried checking the valley cover pan but didn't see anything.

So that only leaves me to believe the rear seal is the problem. Ive watched several videos on moving the transmission back to get access. But im kinda discouraged because this is a 4x4 and the transfer case and transmission look huge together. I have a transmission jack that I will be using and maybe a floor jack for the transfer case.

My question is can the transfer case be removed to make it easier for me?? Are there any kind of special seals between the transfer case and transmission that could be damaged during removal.

And also anyone have an easy way of doing this?? I know the exhaust is going to give me hell

An oil leak at the oil cooler block off plate/cooler line manifold above the oil filter is often mistaken for a rear main seal leak and is mulch more common.

 

[lspann3525]

I checked the block off plate it looks ok. The oil pan and gasket was just changed last year. Today while doing an oil change I noticed a constant oil drip coming from above the starter motor. Is there anything above the starter which could leak oil?

I

 

[Fless]

Crankshaft position sensor is behind the starter. After replacing, a crank variation relearn is recommended.

 

[Rocket Man]

The transfer case is always removed first, then the transmission. I found it harder to remove the transfer case due to the fact I pretty much had to do it with my arms- the trans jack wouldn’t work for it because there’s a crossmember in the way and it needs to be rotated as it comes down. That was a NBS though, never done a NNBS.

 

[89Suburban]

The transfer case is always removed first, then the transmission. I found it harder to remove the transfer case due to the fact I pretty much had to do it with my arms- the trans jack wouldn’t work for it because there’s a crossmember in the way and it needs to be rotated as it comes down. That was a NBS though, never done a NNBS.

Try bench pressing a cast iron full time NP203 into place fuggin SUCKS did it many times YEARS AGO. DOnt missit.

 

[lspann3525]

Crankshaft position sensor is behind the starter. After replacing, a crank variation relearn is recommended.

How is this done???

I have one of them Advanced Scan tools.

Is there a program out there similar to Forscan for Chevys?

 

[Fless]

How is this done???

I have one of them Advanced Scan tools.

Is there a program out there similar to Forscan for Chevys?

AFAIK all you need is a bi-directional scan tool that has the procedure in the software. Most of the simple code readers aren't bi-. The GM tool (Tech 2) will do it, as will many of the shop scanners.

Usually they'll run okay without the correlation, but sometimes they don't, and could have intermittent misfires. You could replace the sensor and have it done at a shop; it's a 5 minute process and shouldn't cost much to have done.

For Android code readers that work with Bluetooth dongles, a lot of us use Torque Pro (Ian Hawkins), and add the extended GM PIDs once the app is running on the phone or tablet. Torque Lite is free; Pro is $4.95.

Torque Pro (OBD 2 & Car) - Apps on Google Play

Measure BHP, Torque & 0-60 Clear car OBD faults View engine data in Google Earth

play.google.com

 

[lspann3525]

This morning I removed the starter to inspect the crankshaft position sensor. There was oil on the block where the 2 starter bolts go but the sensor wasnt wet. I went ahead and replaced it and added some rtv on the o-ring.

Sort of leaning toward my issue being the rear seal. Since the transfer case has to be removed it doesn't look so hard.

Is there a gasket between the transfer case and the transmission??

Im just trying to see what all parts I need before I dig into it. I already have the dorman rear seal with gasket laying round.

 

[Rocket Man]

This morning I removed the starter to inspect the crankshaft position sensor. There was oil on the block where the 2 starter bolts go but the sensor wasnt wet. I went ahead and replaced it and added some rtv on the o-ring.

Sort of leaning toward my issue being the rear seal. Since the transfer case has to be removed it doesn't look so hard.

Is there a gasket between the transfer case and the transmission??

Im just trying to see what all parts I need before I dig into it. I already have the dorman rear seal with gasket laying round.

I would not install a Dorman part in any location that isn't easily accessible because they are cheap and will fail quickly in most instances. Definitely would not use their rear main seal- you are basically doing $1000 worth of labor to replace an inexpensive part. Use the best part possible. I went with OEM on mine.

 

[donjetman]

@lspann3525
I used the Dorman RMS kit 4+ yrs ago and 56k miles ago. No regrets. Mine is still dry as a bone.
I don't remember changing a seal between the tranny and tranfer case.
https://www.tahoeyukonforum.com/threads/rear-main-seal-job-pan-etc-07-yukon-denali-6-2.108334/

 

[Rocket Man]

@lspann3525
I used the Dorman RMS kit 4+ yrs ago and 56k miles ago. No regrets. Mine is still dry as a bone.
I don't remember changing a seal between the tranny and tranfer case.
https://www.tahoeyukonforum.com/threads/rear-main-seal-job-pan-etc-07-yukon-denali-6-2.108334/

I’m glad it worked out for you. My experience with Dorman has been hit or miss and considering how hard it is to replace a rear main, I won’t be taking a chance myself. My OEM was in for 150k and still not leaking when I replaced it with the same as preventive maintenance.

 

[lspann3525]

The Dorman kit I have comes with a new cover,bolts,seal and gasket. It's suppose to be an improved designed. All the other brands came with just the seal.

 

[Rocket Man]

The Dorman kit I have comes with a new cover,bolts,seal and gasket. It's suppose to be an improved designed. All the other brands came with just the seal.

AC Delco and other brands sell the same setup with the seal already installed in the cover. That’s all I’ve ever used. If you trust Dorman, then you trust Dorman. I don’t. They’re the cheapest aftermarket brand there is, and they have a high failure rate. Ask anybody on this forum. I’m sure as hell not using their stuff on something as hard to get to as a rear main seal. OEM lasts 150k or more.

 

[Geotrash]

AC Delco and other brands sell the same setup with the seal already installed in the cover. That’s all I’ve ever used. If you trust Dorman, then you trust Dorman. I don’t. They’re the cheapest aftermarket brand there is, and they have a high failure rate. Ask anybody on this forum. I’m sure as hell not using their stuff on something as hard to get to as a rear main seal. OEM lasts 150k or more.

I find them to be hit and miss but generally trending better. I've used a Dorman throttle body and a Dorman suspension compressor on my '07, and both have been working great for 3-4 years so far. And the Dorman bushing for the transmission shift linkage is superior to OEM, in my opinion. That said, if I can get ahold of the OEM part, I generally do unless the Dorman part incorporates a meaningful improvement, as was the case with the throttle body.

 

[89Suburban]

the Dorman bushing for the transmission shift linkage is superior to OEM,

You have a link for that?

 

[Rocket Man]

I find them to be hit and miss but generally trending better. I've used a Dorman throttle body and a Dorman suspension compressor on my '07, and both have been working great for 3-4 years so far. And the Dorman bushing for the transmission shift linkage is superior to OEM, in my opinion. That said, if I can get ahold of the OEM part, I generally do unless the Dorman part incorporates a meaningful improvement, as was the case with the throttle body.

Dorman is probably getting better, who knows. But I’ll stick with my criteria- if it’s easy to get to in case it fails, or if it’s a better design and is easy to access also, I’ll consider it. But if it’s in a place that requires a lot of labor to access it, never Dorman for me. I’ve been burned before on their stuff. They do have a couple good designs, I’ll admit it and I will use them for that.The rear brake dust shield/ backing plates are one. The OEM design requires the axles to be removed, Dorman designed 2-piece ones that can be installed with the axle in place. The overall quality is typical Dorman though- about half as thick as OEM but if they rust out again, they’re easy to replace. They fit my criteria for easy to access. They also make a oil pan for the 4l60 trans that has a functioning drain plug where the OEM pans don’t. I use that, it makes it easier to drain the trans. It lined up good and didn’t leak. I still don’t trust them for a lot of stuff though, like seals etc or anywhere close tolerances are necessary.

 

[Geotrash]

You have a link for that?

https://a.co/d/6zylvzC

 

[JonnyTahoe]

Crankshaft position sensor is behind the starter. After replacing, a crank variation relearn is recommended.

Replaced my crankshaft position sensor when I replaced my starter. Replaced it with a oem AC Delco sensor. Delco P/N; 213-354 GM P/N; 12560228. After replacing it Engine would not start tried several times. Removed my brand new starter and pulled the brand new Delco Sensor out of the engine. Re-installed the Original Sensor and the engine started right up nothing was wrong with the original sensor I only replaced it because it was 20 years old. Original sensor did not leak a drop of oil. I was lucky enough to be able to re-install it as I almost damaged it trying to remove it. No re-learn required it started right up like it was never removed and years later still running perfectly.