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1966 riviera th400 trans fluid


Rafz66riv

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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...

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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...

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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It's like having a 3G phone that is obsolete when they go to 5G.....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. 

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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.

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  • 1 year later...
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.

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  • 3 weeks later...
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

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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.

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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 by Electra63 (see edit history)
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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.

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Yes to Dexron III/Mercon. 👍

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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.

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