[jgsarasota]

It took me hours of searching online to find this info so I thought I’d compress. I had 2 dealers tell me I can only pump trans fluid back through drain plug due to the fact that the 6L50 lacks a dipstick and fill plug. This is false!


Attached below is a diagram showing the location of 6L59 fill plug assembly.

 

[jgsarasota]

Also attached is a picture of what the drain plug assembly actually looks like. It is located at top of trans on passenger side tightly near the exhaust.

 

[DJS54]

Thanks great to know.

 

[jgsarasota]

I have a 2016 All Terrain just shy of 73k miles. K&N intake, RC leveling kit and add-a-leaf. Mostly highway but plenty of towing and I admittedly have an iron foot. Only issue has been 4x4 actuator which was replaced. Motor is solid! I change oil and oil filter as well as fuel filters as per owners manual.

 

[Burgess159]

When you change the trans fluid, pull the “drain plug.” You won’t get all that much out. To get the most out (without a pump machine), you need to drop the pan. You’ll get about 6 qts. out I believe. I changed my internal filter and fluid (what the pan holds) at 45k miles with AMSOIL OE Fuel Efficient Synthetic fluid. Put the pan back together and then commenced to filling.

I didn’t learn this until after I filled it. I had seen this info somewhere, but had forgot about it, so I’ll share it now. Pull the fill plug (on top of the trans, little black plastic plug which you have in your diagram) and also pull the “drain plug.” If you pull the pan off, you’ll see it’s not a true drain plug as there is a tube that goes up. That drain plug is more like a ‘fluid full check.’ If you start filling with fluid, nothing will come out the drain plug until it’s “full.”

Make sure to be on flat ground, fill it, and when it starts coming out, it’s full. Go drive around and get the transmission fluid up to at least 123 degrees which is operating temp for it, then go back and check the fluid again. Pull the drain plug. Some fluid should come out as the fluid will expand as it gets warm. Once it pretty well stops, put the plugs back in and you should be good. Ran mine for 20k miles now since doing this and it’s still together so I figure I did it the right way

 

[jgsarasota]

Good advice! I pulled “drain plug” and once the fluid stopped flowing I pulled the pan and replaced the filter (about 6.7 quarts), then installed everything back in place and pumped new fluid back in through the “fill plug assembly” with a hand pump, no issues so far and she shifts like a dream.

 

[Burgess159]

Sounds like you did it the right way. Good deal

 

[Torch]

Also attached is a picture of what the drain plug assembly actually looks like. It is located at top of trans on passenger side tightly near the exhaust.

By chance, is there an after market drain fill tube with a dip stick to check the tranny fluid?

 

[Burgess159]

By chance, is there an after market drain fill tube with a dip stick to check the tranny fluid?

Yea there is. It’s posted on here somewhere I think.

 

[Slothman]

It took me hours of searching online to find this info so I thought I’d compress. I had 2 dealers tell me I can only pump trans fluid back through drain plug due to the fact that the 6L50 lacks a dipstick and fill plug. This is false!


Attached below is a diagram showing the location of 6L59 fill plug assembly.

View attachment 8269

what was the torque specs for the transmission pan bolts

 

[Duken4evr]

what was the torque specs for the transmission pan bolts

7.5 ft. lbs, or basically "lightly snug". Don't test your grip strength on them.

 

[Vinolush]

By chance, is there an after market drain fill tube with a dip stick to check the tranny fluid?

Lokar 36".

Change your Transmission, Transfer Case & Diff Fluids!

I finally got around to changing the transfer case and front differential fluids in my truck. The transfer case fluid came out looking decent, but the front differential was absolutely awful looking. There was a good amount of gunk/ metal shavings stuck to the drain plug that has the magnet on...

www.coloradodiesel.org

 

[turbodiverart]

Here's a dumb question. After getting trans to operating temp after a fluid/filter change, do you check the "drain plug" level with the engine running? I know the older transmissions with a dip-stick say check running in park but I'd sort of be surprised that GM would have you check the level under the vehicle while running. Usually when you turn off the engine and the trans stops pumping, fluid drains back into the pan over time so not sure if GM took this into consideration when designing the full tube. I looked on YouTube and of course I find video's being done both ways.

 

[DieselDrax]

Here's a dumb question. After getting trans to operating temp after a fluid/filter change, do you check the "drain plug" level with the engine running? I know the older transmissions with a dip-stick say check running in park but I'd sort of be surprised that GM would have you check the level under the vehicle while running. Usually when you turn off the engine and the trans stops pumping, fluid drains back into the pan over time so not sure if GM took this into consideration when designing the full tube. I looked on YouTube and of course I find video's being done both ways.

Yup, level is checked by removing the level check plug with the trans within the temp range listed (88F-118F or something?) and with the engine running.

 

[the_uglydog]

I noticed a cover plate on the torque converter housing. Is there a drain plug on the torque converter like the old vehicles had? Also, that plug on the side, I pulled mine loose but it won't come out. It wiggles around loose but it seems to be attached inside. Do I just pull harder? Could you refill the trans from the cooler return line using a pump. It seems like it would be easier to get to.

 

[turbodiverart]

I noticed a cover plate on the torque converter housing. Is there a drain plug on the torque converter like the old vehicles had? Also, that plug on the side, I pulled mine loose but it won't come out. It wiggles around loose but it seems to be attached inside. Do I just pull harder? Could you refill the trans from the cooler return line using a pump. It seems like it would be easier to get to.

While I have not removed the shield in question I suspect it's an access panel so you can remove the converter bolts if you needed to remove the transmission. Just like the "dust cover" the old transmissions had except the bell housing on the newer transmissions go 360-degrees around, I assume for added strength vs, the half-bell of old.

 

[turbodiverart]

Yup, level is checked by removing the level check plug with the trans within the temp range listed (88F-118F or something?) and with the engine running.

For some reason I think I remember seeing a sticker that says 122-degrees, strange odd number but that's GM for ya!

 

[the_uglydog]

It used to be the automatic transmissions were the best most reliable part of most cars especially everything from GM. Now, most brands have transmissions as the weak point in almost every car and truck. Over here in PH they can't repair automatics, especially these new ones, you have to replace the transmission if a fluid and filter change isn't done soon enough or there is something else going on. Ford has a parking lot full of new Ranger Raptors with bad transmissions. One new car we bought shifted way too low in every gear. The dealer had no idea what to do, all they did was check the electronics and said it was OK. I finally got the factory to make them do a pressure check since I thought the valve body was stuck. The valve body was stuck. I suggested they remove it and retorque it in the correct sequence but with 1/2 of the torque applied each time, then change the fluid and filter. Fixed! Years ago I had some Allison and Torqueflite automatics that went over 1million miles each with just normal maintenance. I guess now, newer isn't better like it used to be.

 

[SFLTruck]

I noticed a cover plate on the torque converter housing. Is there a drain plug on the torque converter like the old vehicles had? Also, that plug on the side, I pulled mine loose but it won't come out. It wiggles around loose but it seems to be attached inside. Do I just pull harder? Could you refill the trans from the cooler return line using a pump. It seems like it would be easier to get to.

Short answer yes.
That plug has a center part that lifts, once lifted it release the outward pressure on the plug. Once you do this you still have to pry it out a bit, it's rubber it's pretty durable. Then you can pump fluid back into that hole.

 

[the_uglydog]

Thanks! Boy, it sure seems GM hates it's buyers......... This has to be one of the most insane things I've seen done.