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Discussion Starter · #1 ·
Anyone had a leak here before? I was crawling around under the truck today to put my hands on things and make sure my rear suspension is still nice and tight after upgrading last year when I discovered wetness from a small ATF leak between the t-case and t-case adapter where there's a rubber gasket. Unsure if it's the trans output or t-case input that is leaking/weeping. 馃
 

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Anyone had a leak here before? I was crawling around under the truck today to put my hands on things and make sure my rear suspension is still nice and tight after upgrading last year when I discovered wetness from a small ATF leak between the t-case and t-case adapter where there's a rubber gasket. Unsure if it's the trans output or t-case input that is leaking/weeping. 馃
You're gonna make me crawl under and look. Either one is gonna make for some work.
 

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Discussion Starter · #4 ·
Still haven't done anything with this, but my assumption is that it's coming from the t-case input seal based on the condition/color of the ATF. My trans fluid isn't that red anymore. I'll try and get some dye and add it to the t-case, then check it after a while to see if the dye shows up.
 
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2017 colorado z71 modified
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My guess which is just a guess is that it's the output shaft seal on the trans leaking. Was the wrong fluid put in by dealership at some point? Do you do alot of heavy towing? Does your truck sit for weeks at a time? Has your truck ever been jumped? And finally what's the mileage?
 

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Discussion Starter · #6 ·
My guess which is just a guess is that it's the output shaft seal on the trans leaking. Was the wrong fluid put in by dealership at some point? Do you do alot of heavy towing? Does your truck sit for weeks at a time? Has your truck ever been jumped? And finally what's the mileage?
I'm doubting it's from the trans simply because my trans fluid isn't that red anymore, even after a relatively recent service. Dex6 fluid was always used, it has done a fair amount of towing (12k miles or so, mostly with a 5k pound travel trailer), truck doesn't sit, never been jumped, and it's at 72k miles.
 

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2017 colorado z71 modified
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I'm at a loss I've not yet seen or heard of anyone having the t case leak or go out on their colorado/Canyon yet especially with that low of miles.
I have 185k on my 2017 and the only leak I've had was a fuel line wear a hole in it because it had sand between it and a wiring harness.
You say your trans fluid isnt that red anymore, over time and use what ever shade of red that you put in will get darker the atf in the tcase probably nearly looks like ginger 10w30 if you don't change it at 30k. The only thing the pic tells is its either the trans output or t case input seal is gone.

Be careful driving it, t cases are known to eat themselves pretty quick if low on fluid atleast check and keep it topped off
 

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Discussion Starter · #8 ·
I'm at a loss I've not yet seen or heard of anyone having the t case leak or go out on their colorado/Canyon yet especially with that low of miles.
I have 185k on my 2017 and the only leak I've had was a fuel line wear a hole in it because it had sand between it and a wiring harness.
You say your trans fluid isnt that red anymore, over time and use what ever shade of red that you put in will get darker the atf in the tcase probably nearly looks like ginger 10w30 if you don't change it at 30k. The only thing the pic tells is its either the trans output or t case input seal is gone.

Be careful driving it, t cases are known to eat themselves pretty quick if low on fluid atleast check and keep it topped off
I service my fluids regularly, the only reason my trans fluid isn't bright red is because my dealer claimed to do a fluid exchange but only does a drain and fill (Trans fluid has been serviced twice since new), never any trans problems just annoyed with my dealer. My t-case fluid color never turned orange, it was always nice and red. The real question is how much fluid is the adapter seal holding inside? That's what I need to figure out along with checking fluid levels this weekend and seeing how difficult it looks like it'll be to drop the t-case. Or maybe I'll just head over to the local shop that I trust and get an estimate for replacing each seal, depending on which one is determined to be leaking. We'll see. Currently, not to worried about it, though.
 
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