problem automatic gearbox 412

[ulf rickard]

after service there is a loud "highnote" noise when oil is cold in the automatic gearbox. I learned that there are two different kind of oil possible to use. Which one is the correct one ?

The oillevel is NOT low ..... and the noise is RPM depending

The gearbox has also difficulties to change gear from second to third when cold, the first few minutes after start, it goes up and down up and down ......

Never experienced this before oilchange.

Any suggestions guys ?

Ulf, Sweden

[Ashman]

Sounds as though the wrong type of automatic transmission fluid was used in the change. I'm guessing that the 412 automatic uses the same type as the 400i, which calls for Dexron Automatic Transmission Fluid. The brand is not so important but the Dexron label is critical.

Dexron and its variants (see below) was developed by General Motors for its transmissions, of which the TH400 in the 400/400i/412 is.

Do you have a way to verify that Dexron was used? If not, it might be worthwhile to change the ATF with new Dexron anyway just to make sure.

Good luck!

John

Here is a summary

Dexron -- General Motors original ATF for automatics.

Dexron II -- Improved GM formula with better viscosity control and additional oxidation inhibitors. Can be used in place of Dexron.

Dexron IIE -- GM fluid for electronic transmissions.

Dexron III -- Replaces Dexron IIE and adds improved oxidation and corrosion control in GM electronic automatics.

Dexron III (H) -- Improved version of Dexron III released in 2003.

Dexron III/Saturn -- A special fluid spec for Saturns.

Dexron-VI -- Introduced in 2006 for GM Hydra-Matic 6L80 6-speed rear-wheel-drive transmissions. Dexron VI now replaces Dexron III and II, and can be used in GM or import transmissions that formerly specified Dexron III or II.

[ulf rickard]

Originally Posted by Ashman

Sounds as though the wrong type of automatic transmission fluid was used in the change. I'm guessing that the 412 automatic uses the same type as the 400i, which calls for Dexron Automatic Transmission Fluid. The brand is not so important but the Dexron label is critical.

Dexron and its variants (see below) was developed by General Motors for its transmissions, of which the TH400 in the 400/400i/412 is.

Do you have a way to verify that Dexron was used? If not, it might be worthwhile to change the ATF with new Dexron anyway just to make sure.

Good luck!

John

Here is a summary

Dexron -- General Motors original ATF for automatics.

Dexron II -- Improved GM formula with better viscosity control and additional oxidation inhibitors. Can be used in place of Dexron.

Dexron IIE -- GM fluid for electronic transmissions.

Dexron III -- Replaces Dexron IIE and adds improved oxidation and corrosion control in GM electronic automatics.

Dexron III (H) -- Improved version of Dexron III released in 2003.

Dexron III/Saturn -- A special fluid spec for Saturns.

Dexron-VI -- Introduced in 2006 for GM Hydra-Matic 6L80 6-speed rear-wheel-drive transmissions. Dexron VI now replaces Dexron III and II, and can be used in GM or import transmissions that formerly specified Dexron III or II.

Thanks for oil summary, i am going to squeze my mecanic some more. Initially he told me that he used the correct oil,

future will tell !