trans leak

[Jworks]

2011 Sierra 4x4, 5.3.  139k miles.  I just noticed spots of fresh trans fluid on the concrete in the garage.  Checked the fluid level, looked a little low.  So I drove it about 5 miles, got the trans to 126 degrees and checked it again.  It was just below the "HOT" mark.  So I suppose it hasn't lost much.  Is this likely just a gasket?  Is that expensive to replace.  *I had been in the woods today hunting and I may have dragged bottom in one mud hole - but not bad.  Not enough that I had to engage 4x4. 

[CamGTP]

They have not invented the technology yet for me to teleport through my computer and check under your truck to see where the leak is.

 

So for now I do think it's best that you crawl under the truck to see what you might be dealing with.

[Jworks]

Thanks CamGTP.  I did.  Honestly I'm not a trans mechanic so I am no expert.  There is wetness on the bottom up to the front of it.  Two drops hanging off the back bottom of the housing.  With the bottom wet from back to front I'd say its coming from the front.  I guess I'll just have to take it to the shop and hope its not too expensive. 

[CamGTP]

It's hard for me to grasp the exact points you're explaining without pictures.

 

Most leaks are the pan gaskets, the rear tail housing seal on the transfer case where the driveshaft goes in or possibly the front pump/torque converter seal inside the bell housing. That leak tends to come out of the inspection cover/plate on the bottom, it's roughly 2 inches in size.

[Jworks]

CamGTP, my trans mechanic said its the main rear seal (engine).  He can fix it, but yikes, $575 labor plus parts.