Tranny fluid?

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jmikulec
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Tranny fluid?

Unread post by jmikulec » Thu May 18, 2017 9:04 pm

I have a 65 powerglide and need to know what the best oil for it is?
Also, how do I change the gear oil or do I even need to? What oil is best?


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bbodie52
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Re: Tranny fluid?

Unread post by bbodie52 » Fri May 19, 2017 6:25 am

jmikulec wrote:Thu May 18, 2017 11:04 pm

...Also, how do I change the gear oil or do I even need to? What oil is best?
The 1965 Corvair Chassis Shop Manual (section attached) specifies using SAE 80 GL Multi-purpose Gear Lubricant. Gearbox oils are classified by the American Petroleum Institute using API GL ratings. Gear lubricant is now available in both GL-4 and GL-5.
:link: https://en.wikipedia.org/wiki/Gear_oil
The difference between the two standards is discussed in the attached technical paper. The main thing you need to know is that either GL-4 or GL-5 can be used in a Corvair differential THAT IS ATTACHED TO A POWERGLIDE TRANSMISSION ONLY! GL-5 is not compatible with the '"yellow metals" found in the manual transmissions. Since the gear lubricant in a manual transmission Corvair transaxle is shared between the transmission section and the differential section, ONLY GL-4 GEAR LUBE SHOULD BE USED IN A CORVAIR MANUAL TRANSMISSION-EQUPPED TRANSAXLE.

According to the SPECIFICATIONS section (attached), the Rear Axle has a capacity of 4½ pints. The 3-speed Manual Transmission has a capacity of 2.2 pints, and the 4-speed has a capacity of 3.6 pints. (In 1966 a different manual transmission was introduced — I don't have the capacity for that unit, but all manual transmissions and differentials should be filled to the bottom of the threads in the fill plug). The Powerglide Automatic Transmission has a DRY CAPACITY of approximately 13 pints, and an oil pan drain/refill capacity of approximately 6 pints.

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:link: http://corvaircenter.com/phorum/read.ph ... 145,115145
keitho64 - Date: January 06, 2008 09:08AM

Hello, time for another stupid question. I was going to drain the oil on my transmission and differential this weekend since I was changing the shifter seal, backup switch and shift coupler. In all my manuals they show a drain plug on the transmission and the differential. On my car there is a flat boss where the differential drain plug should be and I cannot find anything on the transmission. The car in question is a 1964 Monza, 110, 4-speed car.

Am I missing something or were some cars made without drain plugs? Or is there some other way to drain the oil? Outside of siphoning out the oil I do not know what to do.


steve goodman - Date: January 06, 2008 09:35AM

After 1963 the drain plugs were left out of all stick trans and diffs and pg diffs too.

There have been tech tips written about drilling and tapping the bottom of the diff but that is iffy, not much ground clearance. If the diff was apart you could drill and tap the boss for a drain plug but not in the car, the casting is about an inch thick right there.

The typical way is to use a suction gun to pull the old gear lube out. Remember not to overfill when you are done.
66vairguy wrote:Sat Feb 04, 2017 11:53 am

You won't find any statement in the Shop Manual to change the transaxle lube, but it should be changed about every 30K miles depending on use.

Yes you have to pump the lube out - Brad's electric pump looks handy. I've used a wastewater/oil pump that a drill drives sold for restaurants you can find at some hardware stores. A number of cars don't have drains, not just a Corvair thing.

BTW - The number one cause of Corvair transaxle failure is lubricant that is NEVER changed. Even today the local transaxle rebuilder gets units in that have the original factory lubricant (and whatever was used to top them off).

DO NOT USE GL-5 lubricant in a Corvair manual transaxle. The transmission synchros won't like it. Use a GL-4 (no GL-4/5). Some synthetics are rated safe for "yellow metal" transmission parts and have the proper "lubricity" to make the synchros work. Redline makes two, but ONLY one is rated safe for BOTH the transmission AND differential
jmikulec wrote:Thu May 18, 2017 11:04 pm

I have a 65 powerglide and need to know what the best oil for it is?
Maintaining the proper fluid level in the Corvair automatic transmission is critical to its operation and longevity. Fluid levels should be checked regularly, and any detected loss of fluid should be investigated to correct the cause. Also, be sure to avoid over-filling, as this can cause rotating internal transmission components to be partially immersed in oil and can cause oil foaming (air entrainment), which can also be damaging to an automatic transmission.

Clark's indicates that the vacuum modulator on the side of the transmission has a limited operational life of about 10 years or so. They cannot be repaired, so if you discover transmission fluid in the vacuum hose that connects your Powerglide transmission to the engine, replacement of the vacuum modulator is likely indicated.

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Valvoline DEXRON® VI ATF
Designed to meet the specific requirements of GM transmissions

Officially licensed and GM approved
Provides consistent shift performance for new and old GM transmissions
Outstanding sludge resistance provides superior transmission life
Provides excellent oxidative stability under severe conditions to keep your transmission shifting smoother longer
For all General Motors cars and trucks that require DEXRON®-VI, DEXRON®-III and DEXRON®-II

DEXRON Automatic Transmission Fluid is appropriate for use in Powerglide transmissions. There have been variations in the fluid over the years, with the current designation being DEXRON VI. The changes in the fluid are discussed at the following website...

:link: http://en.wikipedia.org/wiki/DEXRON

The following Clark's Corvair Parts Tech page discusses several issues with Powerglide transmission in Corvairs, including the proper length of the transmission fluid dipstick...
:link: http://www.corvair.com/user-cgi/catalog ... ge=TECH-16
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Attachments
1965 Corvair Chassis Shop Manual - SECTION 0 - GENERAL INFORMATION AND LUBRICATION.pdf
1965 Corvair Chassis Shop Manual - SECTION 0 - GENERAL INFORMATION AND LUBRICATION
(2.94 MiB) Downloaded 2 times
1965 Corvair Chassis Shop Manual - SECTION - SPECIFICATIONS.pdf
1965 Corvair Chassis Shop Manual - SECTION - SPECIFICATIONS
(2.83 MiB) Downloaded 2 times
The Difference Between GL-4 and GL-5 Gear Oils.pdf
The Difference Between GL-4 and GL-5 Gear Oils
(813.25 KiB) Downloaded 3 times
Brad Bodie
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jmikulec
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Re: Tranny fluid?

Unread post by jmikulec » Sat May 20, 2017 2:45 pm

Would this work?Image


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bbodie52
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Re: Tranny fluid?

Unread post by bbodie52 » Sat May 20, 2017 3:28 pm

All of these transmission fluids are of high quality. Valvoline states that their MAXLIFE product meets or exceeds the car manufacturer's specifications, but that the manufacturer has not certified this. They also produce a DEXRON VI synthetic that is certified by the car manufacturer. Non-synthetic versions from various manufacturers can probably be purchased at a lower price and they will still meet the DEXRON VI specification.

Much of the fluid in the Powerglide transmission is stored in the torque converter. It is not easy to completely drain or flush the transmission and torque converter to achieve a complete change of the fluid. I don't know how well the synthetic and nonsynthetic versions mix, or how much of the claimed benefit of the newer formulations would be lost by mixing the old fluid with new fluid that is only added to the oil pan. As long as your transmission fluid is clean and does not have a brown discoloration or burned smell I would suggest sticking with a high quality standard DEXRON VI product instead of paying extra for the synthetic. (If I had just rebuilt a Corvair Powerglide transmission I would likely choose the DEXRON VI synthetic for a complete refill of the transmission and the torque converter).
MAXLIFE™ Multi-Vehicle ATF

Valvoline™ MaxLife™ Multi-Vehicle ATF is a full synthetic formulation with advanced additives to prevent the major causes of
transmission breakdown and help extend transmission life. Developed to help prevent leaks, maximize transmission performance,
reduce transmission wear, and maintain smooth shifting longer than conventional fluids. It is suitable for use in a broad range of
ATF applications including most Ford, GM, Toyota & Honda models as well as Dex/Merc, Mercon LV and many more applications.

Valvoline has conducted extensive in-house testing, independent lab testing, and field-testing to support MaxLife™ Multi-Vehicle
ATF performance in the broadest range of transmissions; however, it should be noted that MaxLife™ Multi-Vehicle ATF is not an
OEM licensed product. The respective vehicle manufacturers have neither evaluated nor endorsed MaxLife™ Multi-Vehicle ATF in
these applications. If an OEM licensed product is preferred we recommend Valvoline DEXRON® VI
, Valvoline ATF+4® and Valvoline
MERCON®V for the corresponding applications.
:link: http://content.valvoline.com/pdf/maxlife_atf.pdf
Valvoline Maxlife ATF.pdf
Valvoline Maxlife ATF
(433.54 KiB) Downloaded 2 times
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:link: https://www.amazon.com/Valvoline-DEXRON ... axlife+atf

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:link: https://www.amazon.com/VALVOLINE-VV3246 ... axlife+atf
Brad Bodie
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wbabst
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Re: Tranny fluid?

Unread post by wbabst » Sat May 20, 2017 10:14 pm

Being an Amsoil guy I am using Amsoil transmission fluid and oil in my restoration project. Amsoil offers part number OTFQT which is their Dextron II compatible transmission oil.

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I chose to go with their product part number ATLQT which is compatible with Dextron III on up.

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What ever you choose it needs to be either matching original compatibility or backwards compatible to the original oil. As time goes by it will become more difficult to find original Dextron and Dextron II. Just pay attention to the labels. Dextron VI is of a lighter viscosity and I chose to avoid it for my application.
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cnicol
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Re: Tranny fluid?

Unread post by cnicol » Sun May 21, 2017 7:02 am

Dex VI is said to start out at a higher viscosity and not "shear down" (get thinner) with age.
This thread might make good reading for those interested in such things:https://bobistheoilguy.com/forums/ubbth ... er=2600620
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