This is another post in our “Common Questions” series.
For new Turbo Regal owners, or others who aren’t sure of exactly what to use in their Gbody Regals.
The original OEM transmission installed in the Turbo Buicks are named the 200-4R.
Lots of other different transmission types have been swapped in over the years (350, 400, etc.).
New torque converters of different sizes and stall speeds have been implemented as well (9″ – 12″).
Because of these changes, the quantity of quarts needed to fill the trans varies.
There’s lots of different automatic transmission fluid (ATF) available, so what should you use in your 1984-1987 Buick Regal Grand National, Turbo T, T-Type, Limited, or GNX?
Most fluids made nowadays are designed to be backward compatible with earlier transmissions, meaning anything you can buy at the local store (or elsewhere) today, you can use in your older vehicles.
(but you can’t use old fluids in the newer cars)
These newer fluids can last up to 100,000 miles (under normal driving conditions), so you will most likely only have to change the trans fluid once during your entire ownership of your Buick Regal.
(of course, if you race your Gbody Regal on a constant basis, you might consider replacing the ATF on a more consistent basis)
Additives of any kind, are generally not needed, and not usually recommended.
Dex III (Dextron 3) was the original trans fluid used in the 1980s Buicks.
Dexron VI trans fluid has replaced the older style Dexron III type fluid.
For the most part, in most applications, Dextron VI (D6) is recommended, and the preferred ATF fluid for the Buick Turbo Regals.
This is a less costly fluid, and lasts longer than all the rest.
There’s lots of name brands (GM, Valvoline, Mobil, etc.) that make a D6 style trans fluid.
(there’s also many off brand names that make this type of fluid as well, but we prefer something more well known. Do you really want to chance ruining your trans by saving literally just a few bucks?)
The Dextron-VI ATF fluids are for use in high performance (or regular) type applications.
They could be full synthetic or a blended formulation, depending on the maker.
(read the bottle specifics which will tell you what exactly it is)
Type F (used in Ford vehicles) is used by some Buick Regal owners, it supposedly grips better (it provides more positive shifts).
However, some people say that this specific fluid doesn’t last as long (that hasn’t been proven though, a few people stated they have been using it for years with no issues).
It’s also said that Type F fluid can’t handle the heat generated that the D6 can.
For street cars and normal driven cars, Type F is usually fine (and recommended by some transmission builders).
For racing only type Turbo Regals, it is said you should only use Dextron 6.
When changing the fluid in a transmission, via dropping the pan, about 4 quarts are needed to refill (for a stock trans, with stock pan).
If you’re replacing all this fluid, be sure to change the filter as well, since you have this all apart already!
Note: if you are installing a brand new transmission, and torque converter, the converter will hold somewhere around 6 quarts alone, so you will need about 10-11 quarts of ATF to totally fill.
(trans type, pan type, converter size, all play a role in how much actual fluid you will need)
When performing a fluid change, you should fill to the line on the dipstick.
Then start the car, put in in drive for a minute (DON’T actually drive the car), then put it in park, recheck fluid level (while the car is running), add more to bring it up to the line. Then repeat this process several times! Doing so will make sure your transmission has the proper amount of ATF in it to prevent damage.
Once that is done, go drive the car a few miles, and recheck the level again.
(and every so often, you should check ALL of your fluid levels, like the oil, trans, engine coolant, etc! You ARE doing this, right?)
As far as the transmission gasket goes, many say to use a cork gasket, installed dry.
Some people place a small bead of silicone on each side of the gasket.
Either way proboably works just as good.
Others (along with ourselves) use a rubber trans gasket, and they work well too.
We think the specific type of gasket is just a personal preference based on past experience and usage.
Just don’t overtighten the bolts and everything will be fine.