dville_gt

iTrader: (5)

The th350 I am running behind the lq9 is a built trans but does not have a manual valve body. I totally forgot to hook up the vacuum modulator. Today when I took it for a cruise it would not shift correctly even with me manually shifting. It did go into second a couple of time part throttle, but sometimes it wouldn't and it never went into third (although my max speed was only 30-35mph so that might have something to do with it)

I was under the impression that the trans would shift fine manually even with no vacuum source (even with a auto valve body), is this incorrect? Does it need vacuum source for part throttle manual shifts?

Fahrenschnell

iTrader: (1)

Simply put....No. You will need a vacuum source or it will not want to shift into higher gears. Only a full manual valve body allows for the lack of vacuum line.

Find a vacuum port and hook it up...

oldgoat69

I second that. Without a vacuum signal a TH350 or TH400 shifts off the governor only.

RATBOX

iTrader: (26)

Ya, that won't work.

stinkybutt

Without vacuum signal the tranny thinks you are at full throttle and shifts later.

Aleck

dville_gt

iTrader: (5)

Yep, hooked up the vacuum line and all seems to be well.