Join Date: Mar 2002
Location: Austin, TX, USA
<BLOCKQUOTE>quote:</font><HR>Originally posted by J early:
Is the vacum modulator the external canister that the vacum line hooks directly onto?<HR></BLOCKQUOTE>
Yes, and THM400 does use a vacuum modulator. If you pull the vacuum line off, you'll be able to insert a small standard screwdriver. Make adjustments about 1 or 2 turns at a time. Turn in to shift later and harder, turn out to shift sooner and softer. Don't over do it though. The adjustment is no substitute for a shift kit. I know several people who tweek the adjustment to get a harder shift which is asking for trouble.
If you can't get the shift adjusted via the modulator within a few turns, you may need to consider modifying the govenor. Also, if tranny fluid drips out when you pull the vacuum line off, replace the modulator.