99 Taurus Ax4n 1-2 Shift Problem

[mcyork]

I have a 99 taurus vulcan ax4n transmission 1-2 shift problem. Having problems shifting 1-2. Either hesitates or goes into neutral and then 2. Some metal in trans when changing fluid. Changed transmission. Same problem. Speedo seems to be working fine. At this point I'm thinking of changing the VSS even though the speedo seems to be working? TRS seems to work when I checked online data with code reader. Any help would be appreciated.

[gohim]

Are you sure you have an AX4N?

The problem you are having is a classic failed AX4S transmission symptom.

How many miles are on the engine?

A bad CPS (camshaft position sensor) can cause shifting problems. The CPS on a Vulcan engine usually lasts 70K-100K miles.

[mcyork]

Are you sure you have an AX4N?

The problem you are having is a classic failed AX4S transmission symptom.

How many miles are on the engine?

A bad CPS (camshaft position sensor) can cause shifting problems. The CPS on a Vulcan engine usually lasts 70K-100K miles.
[/b]

Yes I have the AX4N transmission. Verified with vin # and the trans is stamped also. Like a said, I changed the transmission (Jasper rebuild) and the problem is exactly the same.

[silvapain]

A floating 1-2 shift is an indicator that the pump is failing in the valve body.

[SamH]

I have a 99 taurus vulcan ax4n transmission 1-2 shift problem. Having problems shifting 1-2. Either hesitates or goes into neutral and then 2. Some metal in trans when changing fluid. Changed transmission.
[/b]

Does it do it all the time or just under "hard" acceleration?

When I really get on it (1999 Taurus LX with Vulcan and AX4N) from a standing start then let off a little to get it to shift into second (or third) mine will "search" for the correct shift sometimes lurching and seeming to go into neutral for a few moments. It's done this since day one (bought it with only 11K on it), it now has 103K on it and it still acts the same way. My solution was not bother attempting to accelerate that hard from a standing stop. I have noticed that if you don’t let off it shifts smoothly into second (under very high RPMs) then when you lift it performs as you would expect (or hope).

[mcyork]

A floating 1-2 shift is an indicator that the pump is failing in the valve body.
[/b]

I have discounted the transmission being the problem again. Like I said I just changed it ($1600 Jasper rebuild unit plus my time) and the same problem.

<div class='quotemain'>
I have a 99 taurus vulcan ax4n transmission 1-2 shift problem. Having problems shifting 1-2. Either hesitates or goes into neutral and then 2. Some metal in trans when changing fluid. Changed transmission.
[/b]

Does it do it all the time or just under "hard" acceleration?

When I really get on it (1999 Taurus LX with Vulcan and AX4N) from a standing start then let off a little to get it to shift into second (or third) mine will "search" for the correct shift sometimes lurching and seeming to go into neutral for a few moments. It's done this since day one (bought it with only 11K on it), it now has 103K on it and it still acts the same way. My solution was not bother attempting to accelerate that hard from a standing stop. I have noticed that if you don’t let off it shifts smoothly into second (under very high RPMs) then when you lift it performs as you would expect (or hope).
[/b][/quote]

It happens whether I accelerate slow or fast. The engine revs to 3-4000 rpms and then jumps to 2nd gear. I put in a new (Jasper rebuild) transmission and the problem is the same.

[silvapain]

I'm glad you think it's funny. However, the transmission itself is your problem.

I have this exact same problem with my SHO, and the tranny in it was recently rebuilt and only has 4000 miles on it. I researched about it as well:

http://www.shoforum.com/showthread.php?t=76827


BTW, asking for help then insulting those with more knowledge than you and talking out your ass won't get you many friends on here.

[mcyork]

I'm glad you think it's funny. However, the transmission itself is your problem.

I have this exact same problem with my SHO, and the tranny in it was recently rebuilt and only has 4000 miles on it. I researched about it as well:

http://www.shoforum.com/showthread.php?t=76827


BTW, asking for help then insulting those with more knowledge than you and talking out your ass won't get you many friends on here.
[/b]

Didn't mean to insult anyone. I'm looking for ideas before I do any major surgery in case I missed something. I have asked two well respected local rebuilders as well as this forum and have recieved several different possible solutions(see above). I'm changing the VSS tomorrow because it is a cheap part and easy to replace. Several forum's have suggested trying this and the local rebuilders I know. I know some of the guys at Jasper and like their products, that's why I bought one. Sorry, but I hope your wrong. Time will tell.

[gohim]

You didn't answer the question about miles on your engine. As I wrote before, a defective CPS (or incorrectly driven one, due to a worn-out Syncro Shaft) will cause shifting and other engine performance problems.

It is entirely possible that the problem is not your tranny. It's unfortunate that you didn't seek advice, before blowing the money on a tranny rebuild/replacement.

You can usually see a defective VSS by looking at the speedo for proper operation. But it is a cheap experiment.

[mcyork]

You didn't answer the question about miles on your engine. As I wrote before, a defective CPS (or incorrectly driven one, due to a worn-out Syncro Shaft) will cause shifting and other engine performance problems.

It is entirely possible that the problem is not your tranny. It's unfortunate that you didn't seek advice, before blowing the money on a tranny rebuild/replacement.

You can usually see a defective VSS by looking at the speedo for proper operation. But it is a cheap experiment.
[/b]

The Taurus has 78,000 miles on it. Would the CPS failure show an error code? I'm surprised there is not a code when the trans acts like it does. I've scanned it and had a friend scan it also. No error codes. I took advice when I changed the transmission. Wrong advice, maybe?