vacuum modulator??

[ecko614]

so i was at the junk yard looking at a 95 grand am se, i have a 95 grand am gt. i have a 3100w/ a 4t60e in it. I assumed that the se had the same considering it had a 3100 w/ and automatic(didnt get down and check the pan...but automatically assumed) i look at the vacuum modulator on this particular car and saw it was brand spankin new. Gold in color, literally...brand new. I pulled it off and put it in my back pocket and left. Me seeing it was brand new, i took it because you never know when you might need something. I got home to look at it and comparing it to my car and i found out that the new one from the se has a straight part on the end for the hose to hook to, but mine has this big ass cap thing on it and the hose connects on the side rather than straight out the front. The cap and top on my gt look biger than the unit from the se, but the part that goes into the transmission looks the same to me, whats the deal??

[loner666]

Its an adjustable aftermarket replacement

[ecko614]

so....it wont do no harm slappin it on there?? what can i do bout the hose part?? on my gt, there are a nice amount of lil hoses and tubes and shit runnin off the modulator to a cannister type thing under my battery,and on the se, there was just one hose goin to it(the modulator).. didnt really notice if the other tubes and shit had already been ripped out,or notice the cannister but i pulled the hose and bolt off the modulator and took it off myself....>????

[IsaacHayes]

The aftermarket ones are smaller and cadmium plated (brass colored) and have a screw where the vacuum lines goes to make it shift firmer at cruise (tighten does this). It won't do any harm to use it and if your trans was like mine it the stock might be worn out causing sloppy shifts even on WOT due to worn spring inside.

The aftermarket ones come with a rubber elbow to fit on there. You should of grabbed that while there. There is a T that goes from the manifold to the cansiter and also to this trans modulator. Just make it work wiht some rubber line.

[ecko614]

thanks alot man. ill work on that with the rubber hose. thanks again. whats the deal with being able to adjust it?? im not really intrested in doin it, but ive heard of people getting more solid,firmer shifts from adjusting it. what makes that happen? loosening the screw or tightening the screw? ive done some reading up on how the whole vacuum modulator works, but they left that part out.

[IsaacHayes]

Tighten the screw. What it does is restricts the amount that the vacuum pulls back on the modulator spring so that shifts are firmer when driving normally. This prolongs transmission life as the clutches do not slip as much. It might feel "rougher" as it shifts faster/harder instead of slipping and shifting longer. I have poly mounts in my car and the shifts don't bother me. It feels better to me.

When there is no vacuum the modulator has a spring that pushes a piston out that pushes into a part on the trans raising the line pressure and making it shift faster. When there is vacuum on the modulator (cruising) it reduces the amount of the push of this piston keeping the pressure lower and shifts longer/slower/softer.