TH350 fluid?

Thread Tools
 
Search this Thread
 
Old May 21, 2025 | 01:22 AM
  #1  
CutlassMarc's Avatar
Thread Starter
Registered User
 
Joined: May 2025
Posts: 236
Question TH350 fluid?

Hello, I am having a hard time finding DEX III automatic transmission fluid. Is the newer all syn DEX VI going to be fine or slowly kill the unit.
Thank you for any insight.
Old May 21, 2025 | 04:44 AM
  #2  
Olds64's Avatar
Moderator
 
Joined: Jul 2007
Posts: 18,221
From: Edmond, OK
The DEX VI is supposed to be backwards compatible. I put it in the TH400 in my 71 98 (it leaks ATF quite a bit).
Old May 21, 2025 | 06:36 AM
  #3  
joe_padavano's Avatar
Old(s) Fart
 
Joined: Mar 2007
Posts: 50,791
From: Northern VA
Dex III is available everywhere, including Amazon. I don't understand why you are having difficulty finding it. I've heard that Dex IV and above is not so backwards-compatible due to friction modifiers in the newer ATF. I've never used it personally, so I have no first-hand experience.
Old May 21, 2025 | 06:42 PM
  #4  
CutlassMarc's Avatar
Thread Starter
Registered User
 
Joined: May 2025
Posts: 236
Originally Posted by joe_padavano
Dex III is available everywhere, including Amazon. I don't understand why you are having difficulty finding it. I've heard that Dex IV and above is not so backwards-compatible due to friction modifiers in the newer ATF. I've never used it personally, so I have no first-hand experience.
No autoparts store in my area carries it. As far as amazon, I don't support companies that force employee's to releave themselves in a bottle instead of goin to a restroom.
I did not ask if the local parts store could order it in as I was on way to work and just stopped to pick up a case of oil I had already online ordered/shopped. (buy online, pick up at store)
There was a line and didn't want to make others wait for the kid to have to find someone that would know.
I'll stop by and ask. It is not listed on the autoparts website or I missed it.
Old May 21, 2025 | 07:38 PM
  #5  
oldcutlass's Avatar
Administrator
 
Joined: Oct 2009
Posts: 42,495
From: Poteau, Ok
Have you tried walmart?
Old May 21, 2025 | 09:05 PM
  #6  
CutlassMarc's Avatar
Thread Starter
Registered User
 
Joined: May 2025
Posts: 236
Originally Posted by oldcutlass
Have you tried walmart?
The walmart near me last few times I was there half the shelves were empty. But no I have not looked there. I try to stay out of that store because of the questionable activity being done in the parking lot.
I might come out and find my car not there anymore.
Old May 22, 2025 | 06:03 AM
  #7  
joe_padavano's Avatar
Old(s) Fart
 
Joined: Mar 2007
Posts: 50,791
From: Northern VA
Originally Posted by CutlassMarc
The walmart near me last few times I was there half the shelves were empty. But no I have not looked there. I try to stay out of that store because of the questionable activity being done in the parking lot.
I might come out and find my car not there anymore.
Wally Mart sells this Valvoline ATF that is supposedly Dex III/Merc compatible. I've used it in GM automatics with zero issues.

https://www.walmart.com/ip/Valvoline...-1-GA/15125788



Old May 22, 2025 | 08:32 AM
  #8  
CutlassMarc's Avatar
Thread Starter
Registered User
 
Joined: May 2025
Posts: 236
Originally Posted by joe_padavano
Wally Mart sells this Valvoline ATF that is supposedly Dex III/Merc compatible. I've used it in GM automatics with zero issues.

https://www.walmart.com/ip/Valvoline...-1-GA/15125788


Thanks.
Old May 22, 2025 | 10:40 AM
  #9  
jaunty75's Avatar
Registered User
 
Joined: Jun 2009
Posts: 15,188
From: southeastern Michigan
Originally Posted by CutlassMarc
No autoparts store in my area carries it. As far as amazon, I don't support companies that force employee's to releave themselves in a bottle instead of goin to a restroom.
Originally Posted by CutlassMarc
The walmart near me last few times I was there half the shelves were empty. But no I have not looked there. I try to stay out of that store because of the questionable activity being done in the parking lot.
I might come out and find my car not there anymore.
Wow, your life sounds like it's sheer hell.

No auto parts store carries what every auto parts store normally carries. Walmarts are bastions of illicit activity.

Tell us where you live so we can make sure to stay away from there.
Old May 23, 2025 | 08:41 AM
  #10  
olds 307 and 403's Avatar
Out of Line, Everytime😉
 
Joined: Dec 2006
Posts: 10,100
From: Melville, Saskatchewan
I have used the newer Dexron fluid in older transmissions. Whether it did damage, hard to say. They weren't pristine and eventually failed, probably due to the right pedal and Oldsmobile torque. It is a bit thinner and may leak more, which these old transmissions love to do as is.
Old May 23, 2025 | 11:41 PM
  #11  
Schurkey's Avatar
Registered User
 
Joined: Feb 2019
Posts: 666
From: The Seasonally-Frozen Wastelands
Originally Posted by CutlassMarc
I am having a hard time finding DEX III automatic transmission fluid.
GM does not license the "Dexron" name for use with fluids older than Dexron VI. There is NO SUCH THING as "Dexron III" any more.

However, there's heaps and piles of ATF advertised as "Dex-Merc" or similar, including ACDelco fluid labeled "III-H" which is Dexron III in everything except the name.

Originally Posted by CutlassMarc
Is the newer all syn DEX VI going to be fine or slowly kill the unit.
Shouldn't be a problem. Dexron VI-J is advertised as backwards-compatible for all "Dexron" ATF varieties IN TRANSMISSIONS--so in effect, back to 1967. NOT in Power Steering pumps, not in transfer cases, TRANSMISSIONS ONLY.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Lyle_STL
Cutlass
8
Jun 14, 2020 10:02 AM
Zacc
Transmission
5
May 5, 2018 08:27 PM
jpc647
Transmission
2
Jun 24, 2014 10:11 AM
ollerich29
Transmission
4
Sep 13, 2013 10:59 AM
Stevec
Transmission
2
May 22, 2012 05:29 PM




All times are GMT -7. The time now is 11:34 AM.