What transmission fluid are you using in your turbo 400 transmission

[HeavyHauler]

What tranmission fluid do you guys use in your Chevy turbo 400 transmission?

[siggyfreud]

I used a synth blend of Dexron VI for a filter/refill of a 69 Elky I was working on.

[72c20customcamper]

Older transmission require dextron III. Dont use new VI in older transmissions.

[KQQL IT]

Type F

[siggyfreud]

Originally Posted by 72c20customcamper

Older transmission require dextron III. Dont use new VI in older transmissions.

You can use Dex VI in older transmissions just fine.

From a GM tech bulletin:

Although DEXRON-VI (fig. 1) was introduced into production starting with 2006 model year vehicles (see bulletin 04-07-30-037D), there are still some misunderstandings about it. Here are some facts to help clear up these misunderstandings.

Since GM introduced the first service-fill specification for automatic transmission fluid (ATF) in 1949, it has been necessary periodically to upgrade the specification as part of a continuous improvement strategy. The upgrading process ensures that available service fill fluids are of an appropriate quality for use in transmissions that have been designed around the improved factory fill fluid performance.

IMPORTANT: As with previous upgrades, DEXRON-VI fluids are designed to be backward compatible with earlier transmission hardware. But more important, earlier type fluids are NOT FORWARD COMPATIBLE with transmissions that were designed to use DEXRON-VI.

DEXRON-VI can be used in any proportion in past model vehicles equipped with an automatic transmission, in place of DEXRON-III (for instance, topping off the fluid in the event of a repair or fluid change). DEXRON-VI is also compatible with any former version of DEXRON for use in automatic transmissions.

TIP: Simply topping off the fluid is adequate, but a full drain and replacement is preferred, to obtain the full benefit.

[aerotest]

Dex III

[71CHEVYSHORTBED402]

Rebuilt 400TH and am using Mobil-1 Delvac. Most transmission shops would recommend the familiar route, which is Dexron III. I've heard from a few with solid experience that Delvac is a step-up on a rebuild, so giving it a go.

[Slowboat]

Type F. It is what was suggested with my new B&M torque converter

[Getter-Done]

Type F






.

[54blackhornet]

I put Type F in my TH350 big improvement in shifting over Dextron

[Ol Blue K20]

Type F as per B&M shift kit recommendations. Shifts good....and has held up for many years.

[kwmech]

Type F here also

[68Gold/white]

Originally Posted by 71CHEVYSHORTBED402

Rebuilt 400TH and am using Mobil-1 Delvac. Most transmission shops would recommend the familiar route, which is Dexron III. I've heard from a few with solid experience that Delvac is a step-up on a rebuild, so giving it a go.

LOL, maybe you can post a link to the thread you started about Mobil-1 Delvac!!!

[72LB]

Type F here too.

[71CHEVYSHORTBED402]

Originally Posted by 68Gold/white

LOL, maybe you can post a link to the thread you started about Mobil-1 Delvac!!!

.....

Use at your own risk (rebuild & new only). Two educated presented opinions say if it meets Allison TEF-295 then it makes for a very cool, smooth & happy 400.

Safe route is Dexron III

[demian5]

I have a recently rebuilt TH350 trans and was told to get ATF 4+