In cold weather, my 94 explorer has shifting problems. In order for it to upshift, I need to get it revved over 4000 rpm, then release the accelerator. If I would continue to rev, it will not upshift.

I've changed the fluid and filter, then added a pint of seafoam additive. This seems to have made it a little better, but not much. It has about 120k miles on it. I don't have problems in warm weather.

 

I'm going to guess that after some drivig time, this goes away.....

my bronco 2 does the same thing......I think it's just a matter of the fluid inside the tranny being thick from the cold, and having trouble getting around inside the passages inside the trans.......I've had ALOT of fords that acted like this, but never really bothered with it much

 

there are two servos on the passenger side above the exhaust that harden and and dont seal. Cold weather seems to bring out the worst in these servos. Ford has updated these servos. They are the intermediate and OD servos. I would replace them. You should also check the vacuum diaphragm at the rear of the trans on the passenger side. Pull the rubber vacuum hose off of it and see if there is trans fluid in it, if so replace that also.

 

Where are these "servos" and what are they?

 

like I said they are on the outside of the trans on the passenger side above the exhaust. They are the intermediate and OD servos. Make sure and check the vacuum diaphragm on the rear passenger side of the trans.

 

Do you have to remove the exhaust piping to access the vacuum diaphragm? I can't see it or the servos.

 

No, the vacuum diaphragm is just above the cross member at the rear of the trans pan and you are only going to pull the vacuum hose off of it and see if any trans fluid drips out, if not then it is ok. the servos are above the catalytic converters and yes you do have to remove these to access them. Be sure to spray the exhaust bolts with a break free spray and let is sit awhile.

 

I've looked at it several times and I just don't see the vacuum modulator or any vacuum hose anywhere near the tranny. Does anyone have a diagram, photo, etc?

 

oh sorry silly me I was thinking C4/C6, The modulator is just behind the servos on the passenger side behind a heat shield.

 

Successfully replaced the vacuum modulator. The old one was allowing tranny fluid to get past it. Still need to let off the gas in order for it to upshift. Any other suggestions?

 

when you replaced the modulator did you see the little rod behind it and reinstall it?

you might disconnect the battery for 10-15 minutes then reconnect and drive, but if that dont do it, check out those two servos I was telling you about.

 

I'll try the battery cable. I was hoping the VM and these "servos" were the same thing. Are the servos accessible from the top panel under the carpet? From your earlier post, it sounds like I need to remove the exhaust piping to get to them.

 

no you will need to remove just the catalytic converter only to access the servos. did you see a short rod when you removed the VM and reinstall it?

 

Yes, there was a short pin inside the VM. I made sure not to lose it.

So, it sounds like I need to access the servos from underneath. Is there any reason to open the top hatch also when trying to access the servos?

By the way, what do these servos look like? What are they attached to?

 

go to this thread and check out post #8 there is a pic of a C6. your trans has two servos side by side on the same side in approximately the same location.
https://www.ford-trucks.com/forums/s...d.php?t=337732

there is no access top hatch in an explorer.

the servos look similiar to a mini toilet plunger. there is a rubber top hat with a metal rod in the middle. behind that is a spring. there is a heat shield that protects these servos you will need to remove it has a 10 mm nut that is in a blind spot to remove. they have a retaining ringed cover with an O-ring seal that need to be replaced. the parts at ford should be less that 80 bucks and I would suggest using ford parts and make sure and ask for the o-rings and servos(two of each). You will want to do both of these servos since they are side by side. keep the caps and springs with the correct servo, do one at a time. you might also pick up a new exhaust gasket that goes between the front of the cat assembly and the Y pipe.

the covers can be hard to remove after the retaining ring is removed. you may need to gently pry with two screw drivers from to different directions to get them out. there will be some fluid loss. when installing the new servos, use petrolium jelly to lubricate the inside of the covers, the servo, the bore and the o-ring gasket. there will be resistance because of the spring, you can use a pry bar against the sheet metal and the cover to GENTLY push the assembly straight in and install the retaining ring.

here are the words from the manual.


O/D and Intermediate Servos


Removal

NOTE:
Procedures are the same for both O/D and intermediate servos.

1. NOTE: Catalytic converter(s) may have to be removed.

Remove heat shield, if equipped.

2. CAUTION: Servo is under spring tension. Use caution when removing.

Compress servo cover and remove retaining ring.

3. Remove servo assembly.




Installation

1. CAUTION: Do not damage O-ring during installation. Do not press servo cover and O-ring past relief hole in case, or O-ring damage may occur.

Install servo assembly.





2. Carefully compress servo cover and install retaining ring.

3. Install heat shield, if equipped.

4. Install catalytic converter if removed.


let me know if you need any more help!!