Help with TH400 gearbox

[Snake2998]

Hi - my gearbox is making a hissing sound under acceleration when changing from 1st to second gear. The sound is similar to a smallish very high pressure water jet and lasts a second or so then the box changes normally - it seems to go away once the box is hot. Have noticed that the changes are ever so slightly softer but that might be my imagination.

Anybody know what the problem could be?

[Hotfingrs]

If I remember correctly, the TH400 has a vacuum modulator located on the passenger side of the tranny. Some were located at the back of the trans and others on the side. This modulator controls shift points and you can buy an adjustable one. Could be something wrong with the vacuum line.

[Turbonut48]

Its a Cobra !! Cobra' s Hissssss. lol


Otherwise +1 on hotfingrs


The Nut