6Spd Trans Fluid Change: Interval and fluid

FL335i · October 2, 2016

Wondering what other members are doing for fluid change intervals on the 6spds. I know the book calls for a 45k interval for "severe" and 90k for "normal". I'm leaning toward splitting the difference and doing it around 65-70k. I have towed, not much though, few heavy loads only. I drive in the city a lot and on the hwy a lot. I have 54k so far on the clock. I did add a external 5 micron spin-on filter kit around 43k. So even at 54k my fluid is crystal clear and pink (filter kit cleaned up the fluid big time). However I want to drop the pan and clean the magnet in there and put a new AC Delco filter kit in it. Fluid wise I'm either using AC Delco, Valvoline or Mobil 1 Dex VI. I'm also probably going to put a PML trans pan on it while I'm there. Need to take some clearance measurements and see if I want to do the low profile or deep pan. Looking like me and this truck are in it for the long haul pending nothing stupid happens. I need to get 10yrs and 250k out of it. Just seeing what others are doing and if there is any advise or tips. Thanks in advance.

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redwngr · October 2, 2016

I'd be following the severe service schedule and forgetting doing the pan modifications.

FL335i · October 2, 2016

^ The main reason I want the PML pan is for the drain plug.... Now that I'm running a large 5 micron external spin-on filter once the internal pan filter is replaced it's basically a secondary filter. The magnet on the PML drain plug (or stock pan) and the 5mic filter would catch just about everything. I've been changing the external filter every other oil change since I installed the system. Similar to the Duramax/Allison external filter intervals those guys are following. All I know is in the city rush hour traffic the trans behaves much better after I installed the filter kit and the fluid got a lot cleaner looking after a few thousand miles. For reference, I looked up the stock allison filter and the one I have is physically larger and flows more GPM, while the micron rating is 5 and the stock filter for the allison is 10mic. I'm a firm believer in external filters for the trans. Reason why my F250 and the allisons have them. I might just do the service at 60k and stick to that interval.

jagabom (Esquire) · October 2, 2016

I changed the trans fluid in my 99 - 4.3 every 2 years. It shifted way better every change.

JIm

amxguy1970 · October 3, 2016

Drop pan, fluid and filter change around 75k for all ours. No flush either...

Tyler

Rkaroll953 · October 3, 2016

did you buy that trans filter in a kit? thats a smart idea i like that. yea il prob pay the dealer to change the filter and re fill at around 50k. i did it on my 04 myself and never again lol. ps my work truck is also a 14 5.3 6 speed and it constantly has around 1200lbs in the bed. it made it to 90k with not even a service before it blew. chevy fixed it though under warranty

redwngr · October 3, 2016

^ The main reason I want the PML pan is for the drain plug.... Now that I'm running a large 5 micron external spin-on filter once the internal pan filter is replaced it's basically a secondary filter. The magnet on the PML drain plug (or stock pan) and the 5mic filter would catch just about everything. I've been changing the external filter every other oil change since I installed the system. Similar to the Duramax/Allison external filter intervals those guys are following. All I know is in the city rush hour traffic the trans behaves much better after I installed the filter kit and the fluid got a lot cleaner looking after a few thousand miles. For reference, I looked up the stock allison filter and the one I have is physically larger and flows more GPM, while the micron rating is 5 and the stock filter for the allison is 10mic. I'm a firm believer in external filters for the trans. Reason why my F250 and the allisons have them. I might just do the service at 60k and stick to that interval.

Allison no longer recommends the filter change at first engine oil change. External filter changes are at trans fluid changes. Internal screen in Allision only needs to be changed at a rebuild.

FL335i · October 4, 2016

did you buy that trans filter in a kit? thats a smart idea i like that. yea il prob pay the dealer to change the filter and re fill at around 50k. i did it on my 04 myself and never again lol. ps my work truck is also a 14 5.3 6 speed and it constantly has around 1200lbs in the bed. it made it to 90k with not even a service before it blew. chevy fixed it though under warranty

I did not buy the filter in a kit. I bought the base kit and then bought the 1269 NAPA Hydraulic filter. Put some proper brass barbs on the base plate. Mounted it o the inside frame rail and cut the factory section of hose going TO THE OIL COOLER and hooked the cut pieces to the barbs with high quality SST clamps. It's been awesome. I think I did an entire thread on it. Around 45k the thing started shifting a bit worse in traffic, threw the external kit on and I'm at 54k and it's so much better. I ran a cheap PH7 napa oil filter for about 2 weeks on the intial cleanup, then went to a 1269 filter. Changing the 1269 every other oil change, which is about 12-15k miles. Oh and the external coolant filter was a great idea also... coolant is clean as a whistle at 54k. Shine a light into the overflow tank it's sterile clean. Before I did that filter kit you could see floaties and all kinds of crap in the tank. The coolant kit worked so well I put the same kit on my '89 Blazer, which also turned out like a OEM install.

sdeeter19555 · October 4, 2016

I'm changing the fluid/filter (pan drop) every 50k, and draining what's in the pan every 15k-25k using a vacuum extractor (whenever it's convenient). I also run a larger cooler.

I'm due for the second filter change (pan drop) probably in the spring...

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afireinside7444 · October 4, 2016

How difficult is it to drop the pan on a 5.3 6 speed? I remember reading it was a pain. I used to drop my 08 every 35k

FL335i · October 5, 2016

Wonder if the pan gasket is re-usable on the '14+ 6spd. After reading all the posts it seems like I'm already out in terrirotry that nobody goes to... I'm at 70% oil so in about 4-5k miles will put right at 60k. Perfect timing. Just not sure if I should spend the money on the PML pan or not...

sdeeter19555 · October 5, 2016

Wonder if the pan gasket is re-usable on the '14+ 6spd. After reading all the posts it seems like I'm already out in terrirotry that nobody goes to... I'm at 70% oil so in about 4-5k miles will put right at 60k. Perfect timing. Just not sure if I should spend the money on the PML pan or not...

Reusable on my 2012...I doubt they changed.

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tnchevy · October 5, 2016

I changed the trans fluid every 30k miles on my 2002 model and when I traded it in at 130k miles it was still shifting great. I only do the pan drop and new filter/gasket, never do the flush.

afireinside7444 · October 6, 2016

Is their a issue of clearence with dropping the pan and the crossmember? In a 2015 6speed 5.3?

GMMediumDutyMQ · October 6, 2016

Wondering what other members are doing for fluid change intervals on the 6spds. I know the book calls for a 45k interval for "severe" and 90k for "normal". I'm leaning toward splitting the difference and doing it around 65-70k. I have towed, not much though, few heavy loads only. I drive in the city a lot and on the hwy a lot. I have 54k so far on the clock. I did add a external 5 micron spin-on filter kit around 43k. So even at 54k my fluid is crystal clear and pink (filter kit cleaned up the fluid big time). However I want to drop the pan and clean the magnet in there and put a new AC Delco filter kit in it. Fluid wise I'm either using AC Delco, Valvoline or Mobil 1 Dex VI. I'm also probably going to put a PML trans pan on it while I'm there. Need to take some clearance measurements and see if I want to do the low profile or deep pan. Looking like me and this truck are in it for the long haul pending nothing stupid happens. I need to get 10yrs and 250k out of it. Just seeing what others are doing and if there is any advise or tips. Thanks in advance.

Legal disclaimer: Do not post anything about recommending flushes or boutique lubricants. Void where prohibited.

Sounds like you're in a similar boat to mine, though mine doesn't have the add-on filter. I drive a very similar duty cycle, but I'm at about the 66k mark.

Since I'm all-in for keeping this truck for a VERY long time, giving serious thought to DIY'ing trans fluid changes going forward. Also thinking about a PML pan as well.

Wonder if the pan gasket is re-usable on the '14+ 6spd. After reading all the posts it seems like I'm already out in terrirotry that nobody goes to... I'm at 70% oil so in about 4-5k miles will put right at 60k. Perfect timing. Just not sure if I should spend the money on the PML pan or not...

Pan gasket is still designed to be re-usable on the 14+. Still a 6L80E...