Rubber sealing gasket

[07TrailyLS]

Got under the blazer this afternoon to do some research and found where the transmission bolts to the engine, at the very bottom there is a rectangular rubber large sealing gasket . I noticed that this is leaking transmission fluid or oil can't tell honestly. It's black. My transmission fluid is a good red color at the dipstick but never been replaced that I know of(bought used 2 years ago)Is this gasket something that unbolts and pulls out? Or are we talking about dropping the rear end pulling out the driveshaft and unmating the trans from the engine? thanks guys
Hope the pic shows up. Not mine it's from google but nonetheless that rubber seal is leaking all the way around the outside of it

 

[Mooseman]

That "seal" doesn't really seal anything except possibly dust. Either your engine main seal or the tranny torque converter or pump seal are leaking. If it's black, I'd bet on the main seal.

Is it leaking a lot?

 

[hockeyman]

That rubber seal under there, along with the round metal cap right behind it is what you remove to access and tighten/loosen the torque converter bolts, if needed. You can also use a BFS (Big ******* Screwdriver) to slowly crank the flywheel to access each of the three TC bolts.

My torque converter bolts were loose once I got home from the trans shop a few months ago and I had to remove that rubber seal to access the bolts and re-tighten them. Reinstall the seal once finished...of course.

But as mentioned, I'd guess that you have a rear main seal leak. Not uncommon.

 

[Mooseman]

That rubber seal under there, along with the round metal cap right behind it is what you remove to access and tighten/loosen the torque converter bolts, if needed.

Ah, it has changed since my '02 has two rubber plugs at the bottom for the rear oil pan bolts (green circled) and a round cover towards the front to access the flywheel bolts (blue circled). I guess they wanted to add another way to access the flywheel bolts.

 

[hockeyman]

Ah, it has changed since my '02 has two rubber plugs at the bottom for the rear oil pan bolts (green circled) and a round cover towards the front to access the flywheel bolts (blue circled). I guess they wanted to add another way to access the flywheel bolts.

Actually, I don't think I noticed the forward cover (in the blue circle) when I was retightening the bolts. It might have made the job slightly easier for me, but I may have overlooked it.

The transmission housings on the 4l60 for our platform from '02+ should all be the same... right?

 

[Mooseman]

There could have been some minor changes, like these plugs. On mine, it's two separate round plugs instead of this one piece with the two plugs together. Haven't looked at my 5.3 V8 to see what it has.

 

[07TrailyLS]

I wouldn't say a lot no. No more and no less than what the google image shows. So drop the oil pan and replace the seal on the back of the crank?

 

[Mooseman]

You have to either have to drop the tranny or pull the engine. If it's leaking a lot, you might not have a choice to drop the tranny. I don't think you have to pull the pan for the rear main seal.

This is not an old SB Chevy!

 

[07TrailyLS]

shit... well i"m not one to shy away from an engine problem. i dont have the knowledge you or MRRSM have but 'm sure working on the bottom end of this i6 cant be too bad. only thing that will be hard for me is pulling the engine/trans because of the learning curve involved. it sucks only having one truck. i guess i had it coming by all the manual shifts i do and all the hard launches from 1-2. didnt think it would happen at 85 thousand though. Probably going to let the main start leaking a bit more and procrastinate before fixing it. With my luck ill have the engine and trans out damn near two weeks i just kniow it. thanks moose!

 

[Mooseman]

Main seal leaks like that have nothing to do with how hard it's launched or shifted. It just happens. Dropping the tranny would be way easier than pulling the engine. If it's not leaking a lot, I'd leave it. Both of mine leak and I ain't doin' it!

 

[07TrailyLS]

so its not going to shorten the longevity of the motor? running a google search, theres tons of people with the exact same issue and they just leave it be (including the guys os ssowners). I'm not leaking enough yet for it to matter to me. If it starts making it to the ground, then maybe a replacement. But i think this may be one of those things in my life i finally say "if it aint broke, dont fix it". i'm still tryin to chase down a nasty pop in my left front suspension when i turn the wheel and back out of my driveway. i don't want to have to worry about this just yet.