Tranmission Fluid Replacement

Hey All,

I bought my 2001 Yukon originally at 108k miles back in 2010. I currently only have 140k on it, as the first half of ownership was finishing college and grad school and I haven't had to drive much since then either. I started doing my own work on my vehicles in the past 3 years using the Yukon to learn on, and I've come to realize that I have no idea if the transmission fluid was changed out at 100k from the previous owner. I really don't know anything about the maintenance that he did (I bought the truck on Craiglist private party).

From looking on this forum and on some others, I have seen the recommendation NOT to change the transmission fluid if you are way past 100k miles and haven't had any problems. I don't fully understand why, though I think I read something about different seals.

The transmission fluid is definitely brown, though not as brown as I would think it would be having gone through 19 years and 140k miles if it wasn't changed at 100k.

So my question is, do I go ahead and change it under the assumption that it wasn't changed at 100k? Or is there some risk to changing it now that it is so far past the time and I should just ride it out?

I've read of dropping the pan and replacing the filter, not flushing, so that's what I was thinking of doing.

Any help is appreciated.

Yes I would drop the pan and change the filter but don’t flush it. That’s what I did to mine when I bought it at 140k. Also consider changing the fluid in the differential(s) and transfer case if you have one.

Inspect the fluid. Is it just dirty, or is there particulate and floaters in it? If it's the latter, start shopping for a trans. If it's just dirty, change it and sleep easy.

Drop the pan, change the filter. If you need to cycle fluid again, find a mityvac and suck fluid out through the dipstick, or install a pan with a drain. Don't buy into this nonsense about disconnecting the cooler line and starting the vehicle

Thanks for the replies. I'll plan on moving forward with the pan drop and filter replacement.

Is DEXRON VI good for 00-06 Yukon? Looks like it should be from being on Advanced but just want to make sure before I go with it.

How much would you expect to replace with just a pan drop?

Sub'd

01YukonSC said:

Thanks for the replies. I'll plan on moving forward with the pan drop and filter replacement.

Is DEXRON VI good for 00-06 Yukon? Looks like it should be from being on Advanced but just want to make sure before I go with it.

How much would you expect to replace with just a pan drop?

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Yes and I think it’s about 6 quarts iirc.

The Dexron VI will be correct. The amount of fluid can be a little different depending on pan depth. I would have at least 7-8 quarts there and add as needed while checking the dipstick as you go with engine running, no matter how many times you have to check it. The fluid left over, if any, is great for top offs if needed. Never hurts to have a little extra around. After you top off, with the engine running by the way, roadtest and recheck and add as needed. Make sure when you change the filter that you coat the seal with trans fluid when install.

01YukonSC said:

Thanks for the replies. I'll plan on moving forward with the pan drop and filter replacement.

Is DEXRON VI good for 00-06 Yukon? Looks like it should be from being on Advanced but just want to make sure before I go with it.

How much would you expect to replace with just a pan drop?

Click to expand...

Pan drop and filter would be a cunthair over 4qts. Pans on these aren't all that large. Normal suck-fill with a mityvac is 3.3ish


FWIW my rig seems to like the amsoil multi vehicle atf (not the fuel saver stuff). Seems to feel the best out of what I've tested; fuel effecient amsoil atf, torque drive, valvoline maxife, redline D4, parts store bulk stuff from oreillys and some leftovers from the subaru dealership (bite me). Maxlife is a close second feel-wise but the thing seems to run a few degrees warmer with it.

Sounds great. Thanks for all of the feedback and tips. Planning on knocking it out this weekend.

01YukonSC said:

Sounds great. Thanks for all of the feedback and tips. Planning on knocking it out this weekend.

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Just gonna leave this here....

https://blog.oregonperformancetransmission.com/