Rafz66riv Posted March 8, 2022 Share Posted March 8, 2022 I was wondering what’s the best transmission to fluid to use on a 1966 riviera th400? Link to comment Share on other sites More sharing options...
EmTee Posted March 10, 2022 Share Posted March 10, 2022 Dexron III, or more commonly labled "Dexron/Mercon" or "Dex/Merc". Link to comment Share on other sites More sharing options...
PONTIAC1953 Posted March 10, 2022 Share Posted March 10, 2022 On 3/8/2022 at 1:32 PM, Rafz66riv said: I was wondering what’s the best transmission to fluid to use on a 1966 riviera th400? type A was the original, but replaced and superior to A is now type Dexron III. Link to comment Share on other sites More sharing options...
Larry Schramm Posted March 10, 2022 Share Posted March 10, 2022 You can use any Dexron fluid up to and including Dexron 6. All fluids are made to be able to be back used, just not forward in model years. 1 Link to comment Share on other sites More sharing options...
EmTee Posted March 11, 2022 Share Posted March 11, 2022 I would avoid Dexron VII if Dexron III is available. Dexron VI is synthetic based, which is fine, but it is somewhat thinner viscosity and 'slipperier' (if that's a word) then Dex III. For example, the transfer case in my '04 Silverado calls for ATF, which would have originally been Dex III. When I changed it and filled it with Dex VI (thinking it would be 'better') it stopped allowing me to shift 'on-the-fly'. The slicker fluid isn't compatible with the synchronizers. So, I'd be similarly concerned about the friction material used in older transmission clutch packs... 3 Link to comment Share on other sites More sharing options...
rocketraider Posted March 11, 2022 Share Posted March 11, 2022 If you can find Dex III that's what I'd go with, for reasons EmTee stated above. This question comes up every so often on an Olds forum I frequent, with predictable debate. One 40-ish transmission builder says the worst new fluid formulations are better than the best that were available when T400s roamed the earth. I strongly disagree because modern fluids are designed with different friction and detergent properties than the old formulas were. For some reason that boy can't wrap his head around that, even after a couple of people had serviced their older WORKING transmissions with synthetic fluids and then the clutch packs slipped so much the car wouldn't move. There's rumour the Japanese still have a dirty little secret in their transmission fluid formulas. Something called whale oil... Link to comment Share on other sites More sharing options...
Barney Eaton Posted March 11, 2022 Share Posted March 11, 2022 Can snake oil be substituted for whale oil? Or you could wait a while, convert to an electric motor and not need oil. It's like having a 3G phone that is obsolete when they go to 5G..... what's and old-timer to do? My daughter drove 89 miles in her Tesla but used 124 miles of her range, nothing is simple anymore. Link to comment Share on other sites More sharing options...
JACK M Posted March 11, 2022 Share Posted March 11, 2022 4 hours ago, rocketraider said: Something called whale oil... Real Whale oil is easily detected by its odor. This may only be true if its 60 years old. Found some in a couple of antique outboard gearcases. 1 Link to comment Share on other sites More sharing options...
rocketraider Posted March 11, 2022 Share Posted March 11, 2022 That's why the stuff stunk so bad if it got scorched. But yes, Jack, I've read that whale oil is a component of some newer Japanese car transmission fluids. The Japanese never fully abandoned their whaling industry and actually resumed it in earnest in 2019. 1 Link to comment Share on other sites More sharing options...
Rafz66riv Posted March 15, 2023 Author Share Posted March 15, 2023 On 3/9/2022 at 5:01 PM, EmTee said: Dexron III, or more commonly labled "Dexron/Mercon" or "Dex/Merc". Could I also use this for my power steering reservoir? Link to comment Share on other sites More sharing options...
Amateur Posted March 15, 2023 Share Posted March 15, 2023 Dexron 3 for both auto and power steering fluid. 2 Link to comment Share on other sites More sharing options...
EmTee Posted March 15, 2023 Share Posted March 15, 2023 Either Dexron III or power steering fluid can be used for the power steering. 1 Link to comment Share on other sites More sharing options...
joe_padavano Posted March 15, 2023 Share Posted March 15, 2023 10 hours ago, Rafz66riv said: Could I also use this for my power steering reservoir? All my Oldsmobile factory manuals from the 1960s allow the use of ATF as an acceptable replacement for PS fluid for the power steering. 2 Link to comment Share on other sites More sharing options...
Electra63 Posted April 3, 2023 Share Posted April 3, 2023 On 3/11/2022 at 4:25 AM, rocketraider said: If you can find Dex III that's what I'd go with, for reasons EmTee stated above. This question comes up every so often on an Olds forum I frequent, with predictable debate. One 40-ish transmission builder says the worst new fluid formulations are better than the best that were available when T400s roamed the earth. I strongly disagree because modern fluids are designed with different friction and detergent properties than the old formulas were. For some reason that boy can't wrap his head around that, even after a couple of people had serviced their older WORKING transmissions with synthetic fluids and then the clutch packs slipped so much the car wouldn't move. There's rumour the Japanese still have a dirty little secret in their transmission fluid formulas. Something called whale oil... Hello guys. Trying to narrow this down myself... I need to top up my trans on my 63 Electra for the first time and I've found it challenging to find straight Dexron III It seems that the Dexron III/Mercon or 'Dex/Merc' is easy to find (link): https://www.autozone.com/motor-oil-and-transmission-fluid/transmission-fluid/p/castrol-transmax-dex-merc-automatic-transmission-fluid-1-gallon/945221_0_0? But to find 'pure' Dexron III is challenging. Do you consider the Dex/Merc like the stuff linked above at Autozone to be OK?, or should I narrow it down to something that looks more specifically Dexron III like this ACDelco fluid that I found on Amazon, which (helpfully..) says it 'does not fit' my 63 Electra !? 🥴 https://www.amazon.com/ACDelco-10-9240-Professional-Automatic-Transmission/dp/B01EGOR40Y/ref=asc_df_B01EGOR40Y/ I understand that the VI grade might cause slipping and that not everything is backwards compatible to the 1960s! Heck... I'm barely backwards compatible that far thanks Mark Link to comment Share on other sites More sharing options...
avgwarhawk Posted April 3, 2023 Share Posted April 3, 2023 The bottle at Autozone will work just fine. 1 Link to comment Share on other sites More sharing options...
joe_padavano Posted April 3, 2023 Share Posted April 3, 2023 This thread is about a 1966 Riv with a TH400. Your 1963 Riv has a completely different Dynaflow trans, which is why it's not a good idea to resurrect an older thread that may or may not be applicable. Your trans is supposed to use Type A transmission fluid, which can be difficult (but not impossible) to find these days. Dex III is supposed to be backwards compatible. I wouldn't use anything newer than Dex III. Link to comment Share on other sites More sharing options...
avgwarhawk Posted April 3, 2023 Share Posted April 3, 2023 Dexron III is compatible. Link to comment Share on other sites More sharing options...
Electra63 Posted April 3, 2023 Share Posted April 3, 2023 (edited) 53 minutes ago, joe_padavano said: This thread is about a 1966 Riv with a TH400. Your 1963 Riv has a completely different Dynaflow trans, which is why it's not a good idea to resurrect an older thread that may or may not be applicable. Your trans is supposed to use Type A transmission fluid, which can be difficult (but not impossible) to find these days. Dex III is supposed to be backwards compatible. I wouldn't use anything newer than Dex III. OK thanks Joe. Point taken about resurrecting threads This AcDelco product from Amazon appears to be straight Dexron III - do you agree? https://www.amazon.com/ACDelco-10-9240-Professional-Automatic-Transmission/dp/B01EGOR40Y/ref=asc_df_B01EGOR40Y/ Edited April 3, 2023 by Electra63 (see edit history) Link to comment Share on other sites More sharing options...
rocketraider Posted April 3, 2023 Share Posted April 3, 2023 Dexron III/Mercon should be fine for your Dynaflow. ### Time was Type A worked in all automatic transmissions. Then Ford got crazy in early 60s trying to formulate something that would make Cruise-O-Matics shift better and not slip so much. Type F was the result. Then the Japanese and European carmakers came up with their own proprietary formulas, and now every manufacturer has its own proprietary AT fluid- which usually works only in their transmissions and causes problems when used in someone else's. All in the name of keeping an engine in a very narrow powerband to comply with emissions certifications. Link to comment Share on other sites More sharing options...
Electra63 Posted April 3, 2023 Share Posted April 3, 2023 Good to know. I've seen plenty of places selling Dexron III/Merc so that makes things easier thanks Glenn Link to comment Share on other sites More sharing options...
Frank DuVal Posted April 4, 2023 Share Posted April 4, 2023 Yes to Dexron III/Mercon. 👍 Link to comment Share on other sites More sharing options...
PONTIAC1953 Posted April 4, 2023 Share Posted April 4, 2023 7 hours ago, rocketraider said: Dexron III/Mercon should be fine for your Dynaflow. ### Time was Type A worked in all automatic transmissions. Then Ford got crazy in early 60s trying to formulate something that would make Cruise-O-Matics shift better and not slip so much. Type F was the result. Then the Japanese and European carmakers came up with their own proprietary formulas, and now every manufacturer has its own proprietary AT fluid- which usually works only in their transmissions and causes problems when used in someone else's. All in the name of keeping an engine in a very narrow powerband to comply with emissions certifications. No Dynaflow after 1963, Switch Pitch Super Turbine 400 transmission. Link to comment Share on other sites More sharing options...
joe_padavano Posted April 4, 2023 Share Posted April 4, 2023 8 hours ago, PONTIAC1953 said: No Dynaflow after 1963, Switch Pitch Super Turbine 400 transmission. The current discussion that resurrected this thread is about a 1963 Riv. Link to comment Share on other sites More sharing options...
rocketraider Posted April 4, 2023 Share Posted April 4, 2023 9 hours ago, PONTIAC1953 said: No Dynaflow after 1963, Switch Pitch Super Turbine 400 transmission. 19 hours ago, Electra63 said: I need to top up my trans on my 63 Electra Yes, we DID "change gears"!😏 Link to comment Share on other sites More sharing options...
joe_padavano Posted April 4, 2023 Share Posted April 4, 2023 35 minutes ago, rocketraider said: Yes, we DID "change gears"!😏 Link to comment Share on other sites More sharing options...
drhach Posted April 4, 2023 Share Posted April 4, 2023 I'm going to switch over to Type F this year and see if I notice a difference. Supposedly you get a little more positive shifting. I've been running Dexron/Mercon III previously. Link to comment Share on other sites More sharing options...
EmTee Posted April 4, 2023 Share Posted April 4, 2023 I recall back in the '70s people would swap the Dexron fluid in their TH-400 for Type F to get firmer shifts. Link to comment Share on other sites More sharing options...
rocketraider Posted April 4, 2023 Share Posted April 4, 2023 The rumour was that B&M Trick Shift fluid was nothing but Type F dyed blue and priced higher.🙃 2 Link to comment Share on other sites More sharing options...
joe_padavano Posted April 4, 2023 Share Posted April 4, 2023 52 minutes ago, rocketraider said: The rumour was that B&M Trick Shift fluid was nothing but Type F dyed blue and priced higher.🙃 Pretty sure it's more than a rumor. 😉 2 Link to comment Share on other sites More sharing options...
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