[-qaz-]

My car has started to loose overdrive i think. It does this odd thing sometimes when im crusing on the hiway at about 60 when it starts going in and out of overdrive and after a while i think it stays out of it. I cant recreate the problem, it seems to happen randomly, happened 3 times now. I'm sure loosing a gear is not a good thing, might be a sign of trannys upcoming death? It shifts ok otherwise , not that great does the long ford granny shiftls like it always did and acts crappy when its cold. car has about 165k miles on it its a 94gl with a vulcan and its an ax4s tranny.

So what you guys think? some stupid little solenoid issue or tranny is dropping dead? The fluid is nice and clean and synthetic i changed it every year which was about 10- 15k miles apart . I'm not going to invest gobs of money in this car honostly we all know its cheaper to buy a new taurus or something similar.

So what do you guys think?

 

[-qaz-]

Update: I found a pattern it seems to only happen on small hills and such. Definitely goes out of OD and into D back and forth on little hills or bridges at about 60 mph. Any ideas what can be causing this? What tell the transmission that its on a hill? Is there a sensor for that or something?

 

[socom58]

I think it would just sense the engine load on the hill and downshift. Then, it might upshift when the load decreases (hill gets flatter, etc.) and so on. Never heard of it happening at 60mph though. :headscratch:

 

[-qaz-]

Yeah I know what you mean, I was thinking that too. But a long time ago when I had an idea to control A/F mixture by feeding the EEC my own data rether then sensor inputs Alberto from americanmotorsport explained to me a lot at the EEC tuning section. He mentioned that load is calculated based on a few sensor inputs (maf and something else), he also noted that if this calculation is wrong (as it would be if i would mess with sensor inputs) that error in the calculation can manifest itself in some wierd ways even the transmision shifting wierd or feeling weird. I'm going to try and unplug the maf and take her for a spin on the freeway, see what happens when the computer is guessing what its doing rether then knowing. Maybe the maf is bad or something, I think I'm grasping at straws though... but its worth a shot.

 

[maceslin]

I get the same problem with a SES code that tells me "shift solenoid c inop or stuck open" are you getting any codes

I also will occasionally come to a stop and when I try to accelerate it will not shift out of "neutral" if not careful as stepping on the gas it will slam into gear- this is not good. I found the best way to save the gears when this happens is to shfit from d to 2- this doesn something to the electronics that I am assuming resests or bypasses shift solenoid c which I believe is the one that controls teh overdirve function.

A new shift solenoid is only about $25, the problem is getting to it, I don't think you need to pul the tranny but you would hav to pull alot of other things to access the cover plate.

Keep the board posted as I will when I eventually make repairs- this weekend I am replacing the front crankshaft bearing seal

 

[-qaz-]

I have no check engine light, so i dont think it has codes. I didnt look because the light isnt on. Is the shift solenoid c a problem with ax4n only or is it also commmon to ax4s.

maceslin, you have a duratech so its ax4n I have the ax4s so they arent quite the same, also you have the newer OBD-II computer my car has the OBD-I. So maybe my computer doesnt know that much and thats why there is no code.

Still havent done my maf-less road test, will try to tonight.

 

[J Rod]

my ax4n had the same problem at 81K but I also had a SES light and the OD off light was flashing.

Had the trans rebuilt, clutches were good. A lot of hard parts were discolored from heat but still in good condition. The culpruit at least in my case was a poppet valve in the valve body seizing in its bore.

The fix even though a full rebuild was done was, that the valve was replaced with the same valve from a AXOD non electronic trans because the ax4n's valves were made from a different metal than that of the valve body and as different metals do they corrode each other and it caused the valve to seize. Valve from donor trans is the same as the valve body and it has worked flawlessly for 18k miles.

 

[-qaz-]

Well, just took her for a spin on the free-way. Disconnecting the MAF makes the car not use overdrive anymore. Disconnecting the MAF also makes the check engine light come on as it should. I jsut had the VSS replaced a few month ago so that should be good. The car works fine if I use D instead of OD but i dont like how it feels, cruising at 3k rpm sucks. I know it can go in OD because it does and it stays there and works fine until a tiny hill or bridge or something, also I can confuse it by letting go of the gas and then pressing the gas slightly sometimes, but the latter isnt fair because thats with all atx transmissions. So I'm stumped...

When you guys had your problems were they intermitent or constant? I dont see how it can come and go sometimes and work fine at other times when its a real mechanical transmission issue. What about that shift solinoid, does that come and go also or does it just not go to overdrive? Damn atx... guess this is the price it costs not to ahveto shift and clutch all the time.

 

[-qaz-]

So nobody know if the shift solenoid c is specific to ax4n or not? Poo

 

[J Rod]

mine intermittently would shift into OD, at almost 100k i have not had the solenoid got out ever.

 

[maceslin]

sorry for delay in repsonse, been picking up daughter in college.

I can not imagine that the AX4S doesn't have shift solenoids, everything is electronic now.

My problem is intermittent and goes away when I turn off the ignition which tells me the problem is electronic.

This is a very, very rough guess at trouble shooting theer are probably so many other things it could be and you may want to tkae it to a reputable tranny shop to have them performa a diagnostic and give you a quote

Dave