00 Mercury Cougar 2.5l, v6, 24Valve D.O.H.C. My L. F Transmission gear is cracked. one of the guys at my job said that my axle is missing teeth. My question is, can the gears be welded?

No. replacing the TCC or the OSS, will not make the transmission work. You can unplug these transmissions and they will still work, less OD. Sounds like you may have stripped the torque converter oil pump gear. Common in these older Mercury/Fords.

Possible your linkage is broken. Look at the linkage where it attaches to the transmission and verify the plastic connections aren't cracked.

With a scanner you can drive the car and watch the data to see what is missing for transmission shifting. But struck by lighting tells me that POSSIBLY the diodes in the computer have been compromised . or a internal mechanical fault inside the transmission . THEORY the car revs to 3000 and goes into neutral this means the shift has occurred by the next gear is not holding by pressure (that solenoid is not working) or a internal leak or the band servo has applied but the band does not hold

This is for the mercury cougar, If the trip and speedo is not working when driving I would bet that the tiny gear conected to the speedo motors is broken, It happened to mine. It's easy to fix if you are mechanically able to under stand. The part is available on ebay for a steel gear or go to your local junk yard the thunderbird and cougar or the same. Take out the instrument cluster and remove the speedo assembly, there is a cluster of gears together, remove the gear cluster carefully and you'll see the tiny gear missing teeth. Remove that gear and do the same at the junk yard but beware others my have to same problem, I search two cougar and three thunderbird before finding one that was not broken, I hope this helps. P.S. the main cause of this gear breaking is pushing the trip button while driving. Or age of the car.plastic gears don't last forever.

Manual Transmission - uses Dextrin II or Mercian type fluid. A 85W/90 gear oil may be used with the T500 trannie in very warm climates or if gear/bearing noise is excessive.

1997 Automatic transmission uses Mercon/Dexron II

This is being caused by the seals in the transmission worn out and the heat is causing them to become to plyable thus losing pressure, an overhual is needed

Hi:
Your manual transmission is most likely leaking from one of the drive axle seals.
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Your transmission shifts are controlled by the PCM, Powertrain Control Module. It can be scanned for transmission fault codes which can guide your diagnostics. Autozone can do this for free. You would have to get the car there or find a technician who will bring their hand held scanner to our car.

But, try this first. Disconnect the battery for 1/2 hour. This will clear all the shift tables and the Keep Alive Memory (KAM). Reconnect battery and see if you now have forward gears.

If no luck with fault codes, this could be a possibility that requires a trans teardown.

MERCURY: 1994-2000 MYSTIQUE
1999-2001 COUGAR
ISSUE: Some vehicles may exhibit no forward gear ranges due to the misalignment of the forward/coast clutch cylinder snap ring with respect to the legs of the forward clutch piston.
ACTION: During assembly of the forward/coast clutch cylinder, the gap in the select fit retaining ring should be located midway (i.e., 45 degrees) between adjacent legs of the forward clutch piston. Refer to the following Service Procedure for details.
SERVICE PROCEDURE

1. Prior to installing the forward and coast clutch plates into the cylinder, note the location of the four (4) forward piston legs ( Figure 1 ).
2. Mark the top of the cylinder with a felt tip marker midway between any two adjacent legs (i.e., 45 degrees or 4 external spline teeth from the center of any leg) ( Figure 2 ). NOTE: THE FORWARD PISTON LEGS WILL NO LONGER BE VISIBLE WHEN CLUTCH PACK AND RETAINER IS INSTALLED.
   
3. Following the Service or Workshop Manual procedure, install the clutch plates.
4. Position the ends of the snap ring such that the gap is aligned with the mark on the top of the cylinder (the 45 degree mark) ( Figure 3 ).
5. Perform end clearance check as required.

usually located at shift linkage on transmission

Check your tranny fluid.