97 transport - need help replacing tranny modulator

[rramos27]

please - need help replacing vaccum modulator - i know that its below the air filter housing (from other AF forom). how do i remove the big air filter housing? i remmoved that big black air hose and air filter but can not go further. experienced tranny trouble on stop light - when changed to green light the van does not move - it just went high rev only - after i step on the brake and its suddenly jump forward after releasing brake pedal. Have tranny oil changed (flushed) 2 week ago then 3 days ago it happened again.

After reading a lot of things in AF. I need some expertise if a tranny is needed to be overhaul. I don't really have the money to spend ($2K) for after reading its just a $20 modulator. I already been to the gasket problem when i bought it in 98. Now its also have this whinning sound when its changed gears. by the way the van have 107K miles on it.

thank you for any assistance on this

rramos27

[Headnsouth]

Here's the vaccum modulator location.



Only advice I can give on the tranny is to try a bottle of Auto-rx.
www.auto-rx.com

[Benesesso]

Whatever is wrong, it isn't the modulator. Make sure the trans. fluid level is slightly ABOVE the "Full" mark.

[LMP]

Originally Posted by Benesesso

Whatever is wrong, it isn't the modulator..

Definitely....looks more like some seal or o-ring is gone and pressure is lost...I'd be just so happy to learn a modulator would fix it....
Justs for a try, I'd disconnect the round plug above the modulator...this will release both solenoid and car will only run in 3rd gear.....not an ideal condition, but just to see if bypassing A and B circuits eliminates the "first" gear hesitation.
...and report how it behaves...
here is the solenoid combinaison for 1,2,3,4 (look OD range first 2 columns )
www.avigex.ca/xport/transmissionranges.jpg

[rramos27]

tranny fluid is fine=above the level full level. will let you guys know of outcome
because its freezing outside. thank you for all the information

[Benesesso]

*If* you have to have the trans. rebuilt, make sure to have the shop install all the heat treated parts that are available. GM should have used them originally, but opted to save a few bucks at OUR expense.

Also have the aftermarket TCC valve kit installed into the soft alum. valve body--I think Sonnax or Trans-Go makes them. I'd even have the shop install the lowest gears available, including the chain drive set and the final drive. I installed the lowest final drive avail. (easy swap), and the van runs much better.

[rramos27]

thanks all of you for the information. job is done

appreciated it and this is the best website

rramos27

[Benesesso]

So, what did it involve?

[rramos27]

yes - it was solve BUT I NOTICE A DRIP OF
COOOLANT IN THE BACK, IT SEEMS LIKE THE EXHAUST MANIFOLD
PROBLEM AGAIN DOWN THE ROAD--- ANY SUGGESTIONS BEFORE IT
GETS WORSE---PLEASE ADVISE

[rramos27]

the problem so far is gone but I notice a drip of coolant coming from the back --- it seems like an exhaust manifold problem--any advise before
it gets worse--please advise

thanks

[Headnsouth]

So.....what did you do to fix your tranny?

[rramos27]

my friend have a lift. changed the oil, clean the pan, changed the filter. I also flushed the tranny w/some solvent to take some dirt off. all these after changing the modulator. so far its running fine--but I notice also the coolant leaking--I was thinking of trading the van for a foreign van (sienna/passport) before I get stuck. I have the exhaust manifold done 2 1/2-3 years ago

[Headnsouth]

I would recommend adding some auto-rx to the trans (it'll really clean it up)then drive it for a 1K miles and change the fluid and filter again. I've got a 98 Transport with 172K miles and the trans is a smooth as it was new.
Even if you don't add any auto-rx do the fluid/filter change anyway. Cheap and well worth it.