NEED HELP DEXRON VI Mixed with Nasty Old DEXRON III?

SLiNv_Vic

Original poster
Member
Jun 30, 2015
19
I am going to do a pan drop, I know that I can upgrade to the new DEXRON VI tranny fluid. HOWEVER, the fluid now in the transmission is BLACK as hell. When I pull the dip stick out it carries out small metal pieces. I would say the fluid in there is really bad... So I don't want to flush it in case when the brand new fluid "cleans" all the gunk in the valve body and clogs it up. And also the slippage of clutches...

So the question is, can/should I put 5 quarts of DEXRON VI fluid in, along with old DEXRON III fluid when I do the pan drop?? I am so thirsty let me drink some ATF first:tequila:
 

Sparky

Member
Dec 4, 2011
12,927
Metal pieces?

With black fluid and metal in it I'd be more concerned that the trans is about ready to blow than whether mixing the fluid is a problem. When you say metal pieces is it just like extremely fine powder sludge or actual gritty bits/chunks?

How many miles on the vehicle?
 

MAY03LT

Member
Nov 18, 2011
3,412
Delmarva
can/should I put 5 quarts of DEXRON VI fluid in, along with old DEXRON III fluid when I do the pan drop??

Maybe I'm reading this wrong but do you mean pour the old fluid back in? Or mixing 5 quarts of 6 with the rest of the old 3 that's still in the trans?
 

SLiNv_Vic

Original poster
Member
Jun 30, 2015
19
Metal pieces?

With black fluid and metal in it I'd be more concerned that the trans is about ready to blow than whether mixing the fluid is a problem. When you say metal pieces is it just like extremely fine powder sludge or actual gritty bits/chunks?

Oh no, let me clarify. I was thinking little metal pieces, more like metallic specs, but not big pieces... idk why I typed just metal piece(I am having a Monday panic and my brain is not thinking:bonk:) but, again, there was a a little bit bigger "tiny pieces"(not powder sludge) that came out with the dip stick that concerns me, I should probably take a picture later once I pull the dipstick again.

Maybe I'm reading this wrong but do you mean pour the old fluid back in? Or mixing 5 quarts of 6 with the rest of the old 3 that's still in the trans?

I meant putting 5 quarts of new DEXRON VI in after the pan drop, but I am not sure if I should stick with DEXRON III since there's old DEXRON III inside because I am not doing a flush. So, "mixing 5 quarts of 6 with the rest of the old 3 that's still in the trans?"
 
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Sparky

Member
Dec 4, 2011
12,927
Here's what I'd probably do. I'd probably follow May03LT's video to pump the trans empty of ALL that Dex II fluid, drop the pan, put a new filter in, reinstall, fresh fill, run the engine and shift through all the gear selector modes, then take it for a short drive. Check the fluid after that, and if it is looking discolored then I'd repeat the process.

My brother had an old car that the trans fluid had never been serviced on and the fluid was literally mud brown in color and the trans started slipping, not just changing gears but it wasn't even holding gears well. Flushed that sucker out (what to lose at this point) and it took effectively a double change, but with fresh, clean fluid in there that trans started working again and even a couple years later it is still going just fine.
 
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Mooseman

Moderator
Dec 4, 2011
25,260
Ottawa, ON
Dex VI is backwards compatible with Dex III so you could add Dex VI to a tranny that has Dex III in it BUT, as Sparky said, if your fluid is that nasty, I would do a full fluid exchange, as per @MAY03LT 's video:


This is not a flush, like in oil change places with a machine. This process is completely safe to do.
 

SLiNv_Vic

Original poster
Member
Jun 30, 2015
19
Oh no, let me clarify. I was thinking little metal pieces, more like metallic specs, but not big pieces... idk why I typed just metal piece(I am having a Monday panic and my brain is not thinking:bonk:) but, again, there was a a little bit bigger "tiny pieces" that came out with the dip stick that concerns me, I should probably take a picture later once I pull the dipstick again.
Here's what I'd probably do. I'd probably follow May03LT's video to pump the trans empty of ALL that Dex II fluid, drop the pan, put a new filter in, reinstall, fresh fill, run the engine and shift through all the gear selector modes, then take it for a short drive. Check the fluid after that, and if it is looking discolored then I'd repeat the process.

My brother had an old car that the trans fluid had never been serviced on and the fluid was literally mud brown in color and the trans started slipping, not just changing gears but it wasn't even holding gears well. Flushed that sucker out (what to lose at this point) and it took effectively a double change, but with fresh, clean fluid in there that trans started working again and even a couple years later it is still going just fine.

I am back with a pic, I think I was too pessimistic last time. It doesn't look so bad this time. So you say a complete fluid change.
IMG_0364.JPG
 

SLiNv_Vic

Original poster
Member
Jun 30, 2015
19
Dex VI is backwards compatible with Dex III so you could add Dex VI to a tranny that has Dex III in it BUT, as Sparky said, if your fluid is that nasty, I would do a full fluid exchange, as per @MAY03LT 's video:


This is not a flush, like in oil change places with a machine. This process is completely safe to do.

Okay, I see, I was just trying to make up my mind if I want to do a pan drop or a complete fluid change.

I've watch this couple of times before. Actually I've watch almost every video of MAY03LT:2thumbsup:
 

Mooseman

Moderator
Dec 4, 2011
25,260
Ottawa, ON
That don't look like tranny fluid, more like engine oil! I don't see no red there at all.
 
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SLiNv_Vic

Original poster
Member
Jun 30, 2015
19
That don't look like tranny fluid, more like engine oil! I don't see no red there at all.

Well, this is my friend's car and he knows nothing about it, I don't think he never serviced it in the pass two years. Now I drive this car a lot so I am going to catch up with the maintenance for this car...
 

Sparky

Member
Dec 4, 2011
12,927
Okay, I see, I was just trying to make up my mind if I want to do a pan drop or a complete fluid change.

I've watch this couple of times before. Actually I've watch almost every video of MAY03LT:2thumbsup:

Still drop the pan and change the filter regardless (I figure you know that but just making sure!).

That don't look like tranny fluid, more like engine oil! I don't see no red there at all.

It looks like really, really worn out trans fluid to me. Only slightly worse color than the trans fluid was in my 02 when I bought it at 112k. That trans is at 215k by the way.
 

MAY03LT

Member
Nov 18, 2011
3,412
Delmarva
I got you now it would be fine with 5 quarts of 6 mixed in with the old stuff. When I first did the trans filter on mine (at around 50K) it was recommended to add dex6 and it didn't give me any problems (now at 190K).
 
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Paul Bell

Member
Aug 16, 2014
460
I would definitely drop the pan, clean it up really well and get it back up with a fresh filter. Make sure you clean the pan and magnets real good. THEN I'd do the full flush. This transmission takes 13 quarts so you'll need at least 20 quarts.

I wouldn't worry too much about which fluid to use. I usually go for the cheapest brand name (Penzoil, Castrol, etc.) fluid. Stay away from store brands like Pep Boys or AutoZone fluids.
 
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SLiNv_Vic

Original poster
Member
Jun 30, 2015
19
Yeah, I already booked the shop hours for the coming Saturday and I will do a full fluid change. Just bought ACDelco DEX 6 from amazon, didn't even have the process of choosing which brand lol, I trust acdelco too much
 

seanpooh

Member
Jan 24, 2012
461
I used Amsoil Torque Drive (2.5 gallon $93) which is still DEX III but fully synthetic. Along with that I have a external cooler along with a remote transmission filter (size of a Ford V8 filter) with a hard drive magnet on it which extends the life of the fluid while cooling it further.

Stay away from the castrol tranny fluid, I think it's junk/generic and obviously store brands. I mean, if mobile1 is around, atleast get that.

10 quarts was enough for me to do a complete flush and fill up the tranny.

I had to rebuild my tranny twice, I'm a little protective now. Paying over $1K everytime isn't worth it.
 

mrrsm

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Oct 22, 2015
7,640
Tampa Bay Area
Please view Post #15 (and beyond for related Tool Images) for information on "How to Reverse Flush your Transmission Fluid Cooler" as well... to eliminate a "Black Mung Well of Gunk" that ordinarily is inaccessible. This action MUST be done with the transmission lines disconnected from the passenger side of the 4L60E Transmission and you should NEVER Reverse Flush INTO the Transmission:

http://gmtnation.com/forums/threads/transmission-issues.15608/#post-504609
 
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