What’* up all! Hey, I’m looking at my vacuum line that’* supposed to go into my tranny. Now I see that the diagram at my hood catch of how my vacuum lines are supposed to route through particular connections on the engine. The one vacuum line that is supposed to go into the tranny coming from the canister on the driver’* side at the fender wall has a screw in it which is the same as capped off. Right? I see that it’* supposed to also go to the thing on the top of the engine where all the other lines go to. Don’t know what it'* called, maybe the PCV valve? Does this make a big difference that the vacuum line is not going into my tranny? My tranny is shifting hard in first gear and taking along time to shift over to 3rd but when I checked the fluid it’* still nice and red so I know I’m not burning my tranny up. Does anybody know what’* up with this whole picture?

That'* the vacuum modulator that controls line pressure and shifting. It will shift very hard if disconnected and plugged. I suggest hooking it back up.

thanks willwren that did the job! i went to Advance Auto and got a 3-way adpter for the hoses. the screw in the hose was actually done like that when the shitt mechanics install what i think is a new, used engine. it'* shifting perfect nice and smooth now from first to second and not really hanging in high second gear before shiting to third. still acting a liltte hasitate when shiting to third though . what suggestions do you have next for this one?

Hey, my bonne shifts kinda hard, could this be the same problem?? If so, where is this vacuum line??? Can some post a diagram or a pic?

Sallan, we don't know if you even have the same transmission. Please put your year and model in your signature by editing your profile. We all do this for that very reason.

Assuming you DO have the same trans, look at this pic:


On the far right bottom of the pic, do you see the trans wiring harness connector? Then right below it a little thingy ^^RIGHT THERE^^that looks gold with red lettering? That'* the modulator (stock looks bigger and gray, this is an adjustable replacement modulator in this pic).

Make sure the vac line is connected and not leaking/cracked, etc.

87-97 NON-supercharged get the 4T60 or 4T60E.
91-96 SUPERCHARGED also get the 4T60E (HD).

Everything newer than these two groups will have NO modulator.

I have tried to put my make and model in the box but it wont save???? I have a 1993 bonneville ssei (canadian version). Now, that pic helped a little, but I cant really see what you talking about, is there anyways to get a better pic??

My vac line was cracked going into the tranny, I ended up getting a roll of vac line and replacing everything I could find in that size.

I figured they all could be freshened up, as they were all nasty.

All is well now!!

Bob

I'm having the same 1-2 hard shift problem. I'll have to look in to this vacuum line thing.

will i found the vacuum modulator last night, and the line going to it looked like it had a small crack in it. I'll try replacing it today.
How can you tell if the vacuum modulator is bad?