1981 500 sel 722.3 transmission. I have no forward gears, but have reverse. When I lift the back wheels off the ground I have all gears works fine, anyone have an idea whats wrong ?
Thanks
Doug J
TX

Most likely something having to do with band B2. I noticed you replaced the B2 servo piston in an earlier post. Recheck the B2 servo if you haven't already. Unless the old B2 servo was in pieces or the lip seal had failed, I'd be checking to make sure the fluid level is OK, and if so, use a pressure gauge to check line pressure at the test port on the RH side of the transmission and see if that's OK (most likely is since reverse seems OK, but line pressure increases in R normally so it's wise to check line pressure in D) Either that or the O-ring in the B2 servo bore is leaking (the one that seals the B2 servo cover), but there'd be lots of fluid on the ground in that case. Another possibility, although less likely, is the selective pin that goes in the opposite side of band B2 fell out when you pulled the B2 servo. That can be reinstalled, but the valve body, separator plate, and B2 plastic guide have to come out, but that can be done from under the car in any case.

Without B2 (gears 1, 2, and 3) or K2 (in fourth gear) being applied, no torque can transmit through the rear gearset. However, with the wheels off the ground sometimes just enough torque can make it through the clutches and gearset to turn the wheels. Reverse works since the front gearset is outputting reverse to the rear gearset and there is a one-way clutch there that locks when reverse torque is applied, so no clutch or band needs to be applied in the rear gearset.

__________________
Erich Loepke
2010 Ford Focus
Currently Benz-less

Thanks for the detailed reply, I will do that pressure test you suggested and yes I have installed a new B2 piston (longer pin) seal and sleeve.
I have a few questions:
Can I see the selective pin on the other end or do I have to remove the items you mentioned?
From what I gather your saying since the B2 band initiates the whole process then the problem lies with the band?
Thanks again
Doug J

The pin will fall down to the plastic guide and probably stay there. Anyway, the separator plate is going to stop it from falling into the pan. So, all that stuff will need to come out.

If you have compresseed air and a rubber tipped air gun, you might be able to air test the B2 servo (you'll need the separator plate off to do this) and see if it applies normally, or if there is a leak at the seal. If you do any of this and notice burn marks on the K2 clutch cylinder where the B2 band rides, this is no cause for concern unless the B2 band is somehow damaged. The service manual states that transverse cracks in the B2 band are of no concern. You would have to have the transmission apart on a bench to see this, however. The B2 band has what looks like a high temperature friction material with asbestos or something similar. To make the 3-4 shift, B2 has to unapply at the same time that K2 applies. If for some reason both were applied at the same time, the output shaft would stop turning, which would generate heat at B2 and/or K2 while that was happening unless both were strong enough to bring the car to a skidding stop. Now, the B2 piston can receive fluid pressure at either side so it applies B2 or it moves the other way and unapplies B2. This can be air tested as I described above.

Also, you could have a broken B2 band. If you take off the valve body, separator plate, and the B2 plastic guide, you should be able to use your fingers to compress the ends of the band. If there is no springiness to the band, it is most likely broken.

__________________
Erich Loepke
2010 Ford Focus
Currently Benz-less