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Replacing trans filter on 6l80

larboc

Limestone cowboy
Joined
May 19, 2020
Member Number
237
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Da yoop
So I decided that 300k miles was a good time to change all the fluids (diffs, t-case, atf) on my '12 1500. I pulled the seal for the trans filter tube with a pair of needle nose and then pushed the new filter in that had a seal on it already out of the box after coating the seal with ATF. I pushed the new filter in and it took a little bit of wiggleing and felt like it went in all the way, and then pan went on fine but I never actually looked to see if the seal was flush with the case. Later on I was closing out all data that I used for torque specs and see that there is a tool for installing that seal and now I'm paranoid that I didn't install the seal before installing the filter. Truck seems to be shifting fine. Any reason to be worried?
 
You'd know if it was sucking air, if it's working it's sealed. If it starts acting up you know where to start. I've done a couple of them and never used anything special to put that seal in, did it the same way you did.
 
Yes you should be worried about disturbing a 300k mi trans. If it is still happy after 300k mi there's no way I would open it and let whatever magic is inside out.

I have no useful response to your question other than GM transmissions seem to live the longest when zero maintenance is done to them.
 
If it wasn’t sealed it wouldn’t be pumping ATF. Your transmission wouldn’t work. You are fine.
 
Yea... 300k miles... that mother fucker is full of coffee grounds. And now you just dumped a bunch of fresh soap in there. Good luck with all that. :flipoff2:
 
I given a bunch of 200K mile transmissions their first fluid change, and never has it resulted in problems that weren't already there, and in some cases new fluid fixed problems that it had.

wives tale is wive's tale.
new fluid > old fluid.
 
I given a bunch of 200K mile transmissions their first fluid change, and never has it resulted in problems that weren't already there, and in some cases new fluid fixed problems that it had.

wives tale is wive's tale.
new fluid > old fluid.

Modern trans- not much going on 0-150k or even pushing 200k.... but 300k?
 
Modern trans- not much going on 0-150k or even pushing 200k.... but 300k?

changed an AW4 at 333K. no idea if it had ever been serviced. Still a 27 spline original unit.

new fluid is better than old.

you ain't gonna change my mind sweetheart
:flipoff2:
 
changed an AW4 at 333K. no idea if it had ever been serviced. Still a 27 spline original unit.

new fluid is better than old.

you ain't gonna change my mind sweetheart
:flipoff2:

No i get it... old wives tale.... i understand the reasoning completely.... but at some point you've got a trans full of brown brake fluid and broken down goop. All of the sudden at 300k you care? You're the dad that left for cigarettes in 1989 and never came back now patting your son on the back for his job promotion. He might thank you and appreciate the effort, but that weekend he's going to be in a speedball coma "under the bridge downtown".

:flipoff2:
 
Modern trans- not much going on 0-150k or even pushing 200k.... but 300k?

Highway miles....
PO said trans was replaced at 180k, I could have mentioned that I guess. Looked mint inside the pan, normal sludge around magnet.

Off topic but thank you GM for going to reusable gaskets. I bought a new gasket scraper and a fresh cartridge of rtv for the diff cover and trans pan and was very happy to not have to break into it or wait for it to cure. Diff cover and trans pan are reusable gaskets, front axle plugs are o-ring. T-case plugs are npt though so I had to use some dope but still the whole process was much easier and faster not having to scrape gaskets or use RTV.
 
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