Rear main Seal

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lspann3525

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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
 

Geotrash

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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.
 
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lspann3525

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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
 

Rocket Man

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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

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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.
 
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lspann3525

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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

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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.
 
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lspann3525

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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.
 

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