I have a 1987 Ford Aerostar XLT, with (amazingly) 640,000 miles on the engine and body. I have had it for a few years, and I am having problems with the transmission.

I recently replaced the vacuum modulator and the transmission shifted beautifully for about a month, but, now, it has to be ran for about a mile and a half in 2nd gear and manually shifted up to third, but, after it finally kicks over....it does great for the rest of the day.

I was wondering if I happen to have a bad vacuum modulator. Sometimes the car also will not go into overdrive, or at least I don't hear or feel it do so.

The car shifted alright before I changed the vacuum modulator, but, jerked going into second gear from first. That problem is now fixed, but, it is not going into third until the car gets good and warmed up.

I have to do this each day and if the car has been setting for 5+ hours. Like I say, the transmission shifted alright before replacing the vacuum modulator.

I also have another problem. My car has digital dash and for some odd reason, the alternator light flashes and dings for about 5 minutes after starting the car. I have taken the car for computer diagnostics, which no codes found. I have checked all of the wires, to the best of my ability, and everything is connected correctly. My alternator puts out the recommended amps and the battery holds the correct charge. The dinging of the dash and the blinking of the light bothers me though. I am just not sure what to do.

If anyone could help me....I would GREATLY appreciate it!

Thanks again!

-J-

Also....my car is on it's third transmission...the motor is original....few issues with it...but.....I will write a story for you all another time....hee hee

 

Just a thought,haven't heard you say anything about adjusting the bands,did mine and feel it helped,more peppy,how long this will last?
Keep us posted.
Mojo Hobo

 

did you say 640,000 MILES??!!!...must be a typo!!! :-).....that's around the earth at the equator like 45 times!!!!...

 

CNAJP,

I have a 1990 with the digital dash. I once had a problem with the thing intermittently flashing the low oil pressure warning at me. The first time it happened, I thought I lost too much oil from its various leaks. But the dipstick showed sufficient oil, and the lack of clattering noises from the engine convinced me that the oil system was fine. One time when the alarm came back, I gave a sharp rap to the top of the dash board, and it stopped. This told me that there was a bad connection in the instrument panel somewhere.

I took the panel apart to find the circuit boards that made up the instrument displays. There are two large scale modules that are clamped onto the main circuit board. I took them off and cleaned their contacts and then covered them with a rust inhibitor before re-assembling. That was a few years ago, and I've never since had a false alarm or reading.

If you want to do this, you should take care to ground yourself to the chassis to dissipate any built-up static charges before touching the circuit boards.

 

When the modulator goes out you can get a lot of debris in the transmission that can cause problems later. A fluid change may help. Install a transmission cooler line filter also. It may be too late but it is cheaper to try that than a rebuild.

Wix transmission/PS filter #58964
200 psi working, pressure relieved, magnetic
change yearly or 12000 miles
Ford equivalent filter kit #XC3Z-7B155-AA
filter alone #XC3P-7B155-BA

 

Is there a short piece of rubber hose on that modulator, and did you change it?

 

Hi

I drove the car today...and yes...it has 640,000 miles on it....seriously....the motor on that car will not die or even lose power. It has been through a couple transmissions though.

I recently changed the modulator...losing the pin....not sure if the one I made is the right length or even width, but, the car drives very well sometimes, and sometimes I have to drive the car a couple miles in 2nd gear and I can give it gas, and it will pop into third....never did that until I changed the modulator....so...I figured that had something to do with it. Also, I bought the 18 dollar modulator at Advance Auto...so...I am not sure how reliable they are.

The problems with the trans that I had before reversed after I changed the modulator.....instead of shifting hard into second..it sometimes doesn't want to shift into third....but...it downshifts well, with very little hesitation, but, once in a while, it jerks back into first.....nothing major though....just a little jerk...at takeoff....rarely happens though.

I am also going to work on the dash problem this weekend...and see what happens....Thanks to everyone for advice on keeping my great car running well

Thanks again!

-J-

 

Go to a junk yard and get one. That pin is hard to make the right length and wieght.

 

Hi,

Can I use this WIX unit as a line filter for my Aero Power Steering?
Thank you

 

You think a modulator from Autozone will be ok or would you recommend I get it from Carquest?

I don't want to run into your issues.. Did you ever replace it to see if that was the problem?

Shawn

 

Hi

I would reccommend Autozone above anywhere else. I have had my best luck with them. I am not currently driving my van....but....instead, in the process of redoing the whole van...because I love it so much. I haven't replace the vacuum modulator yet, but, that is definitely my next project

Best of luck!

Jeremy