Oil Pan Replacement

[Aeterna]

I have a 2007 Tahoe z71 4x4, it leaks from the oil pan, oil cooler plate, and I think rear main but not 100%.

Ive done some searching and cant find a definitive answer. In the near future I am going to replace my oil pan gasket and pickup tube oring.

my question is, do you have to put rtv on anything when replacing the oil pan gasket? Ive come across some people saying to put rtv at the corners or edges and others have not said to do that?

i would imagine putting rtv could make the seal uneven and thus leak. I am using ac delco parts for the replacement.

 

[Larryjb]

You must use RTV at the corners or it will leak. BUT, it must be an oil resistant RTV and not too much.

If you follow the instructions properly, it won't make an uneven seal. The rear and front covers meet at the corners of the oil pan, making the mating surface uneven. The RTV actually makes the surface even for a proper seal.

When you remove the oil pan, you will find remnants of old RTV between the rear/front covers and the block. I took a razor blade and cut a tiny bit of this old RTV out because it was protruding below the gasket surface. The new application of RTV would fill in the gaps nicely. I did mine 4 months ago and haven't had any leaks since.

 

[Aeterna]

Gotcha, so this rtv does not go on the oil pan mating surface. instead it goes on the front and rear covers that I assume will hang down a bit once the pan is removed?

 

[Larryjb]

Yes, that's right.

Don't worry, it will be really obvious once you have the pan off. They won't "hang down". They are firmly bolted to the ends of the block. However, because the mating surface isn't one continuous machined surface it absolutely needs the RTV. Again, it'll be obvious when you get it apart.

The hard and frustrating part will be the cleaning of the gasket surfaces. I always hate that part the most.

There was a discussion at the end of March and beginning of April of this when I did mine. We almost got into a heated argument about whether to separate the outer axles from the front differential! For me, it was so easy to pop off the 6 bolts holding the outer axles to the inner axles, then lower the front differential. Many other guys don't bother and just pry the front differential as they remove the pan. But, from your signature, I can't tell if you have 4wd or not.

 

[Aeterna]

Yes, that's right.

Don't worry, it will be really obvious once you have the pan off. They won't "hang down". They are firmly bolted to the ends of the block. However, because the mating surface isn't one continuous machined surface it absolutely needs the RTV. Again, it'll be obvious when you get it apart.

The hard and frustrating part will be the cleaning of the gasket surfaces. I always hate that part the most.

There was a discussion at the end of March and beginning of April of this when I did mine. We almost got into a heated argument about whether to separate the outer axles from the front differential! For me, it was so easy to pop off the 6 bolts holding the outer axles to the inner axles, then lower the front differential. Many other guys don't bother and just pry the front differential as they remove the pan. But, from your signature, I can't tell if you have 4wd or not.

Awesome thanks, i have 4wd. I plan on unbolting the passenger side axle and the passenger side diff mounting bolts to let it hang. I believe with that and removal of the sway bar there should be some wiggle room. But then again, i may drop the diff as the seals on it are weepy.

 

[Larryjb]

I never removed the sway bar. However, if you want more wiggle room, you can disconnect the center link from the pitmann arm. This way you are not affecting the alignment in the end, but doing this needs some good leverage or impact tools.

I know this is titled "Rear Main Oil Seal", but I was trying the oil pan first in case that was the leak. It wasn't, so the entire thread went onto doing the rear main as well. This post in the thread contains a pdf for what I did for the oil pan gasket:

https://www.tahoeyukonforum.com/threads/rear-main-oil-seal.117639/page-9#post-1430691

The discussion begins a few pages earlier, which may give you more insight into what you're getting into.

 

[Aeterna]

Thanks I appreciate it. I will hopefully get to replacing it soon.