A4ld on last legs

[generalpeon]

Hi, I have a 4.0 2wd with an a4ld and the other day when I was going up a hill out of the blue it slipped out of gear. After I had it towed it home I did a flush (figuring what could it hurt) and now it wont budge when I put it into overdrive, but if I put it in park then to regular drive it shifts fine. Is this a problem with the valve body? shifter problem?

 

[Glacier991]

In terms of what is used to apply first in OD as opposed to D it is the coast clutch. I do not see that this is a meaningful difference in opereation. The fact you have all gears in D (save 4th) more or less confirms everything else is ok.

I would start by looking for issues with linkages and the Z link then the manual valve. You COUDL have a VB issue, but in truth the internal parts that give you first in D also give you 1st in OD..... I am a little mystified myself.

 

[BrooklynBay]

Did you try to adjust the bands? The first one is the overdrive band. The second one is the intermediate band. The third one is the low/reverse band. If you are having overdrive issues, try to adjust the OD band, and see if there is any difference. Check your vacuum line going to the modulator for any signs of ATF. There are servos controlling these bands. The first 2 are really difficult to replace while the transmission is still on the vehicle. The heat from the exhaust dries them out, and could cause engagement issues. Did you replace the transmission filter when you did a flush? Start with the band adjustment. If that doesn't make a difference, then try to retorque the VB bolts.

 

[generalpeon]

thanks for your help guys but I fear that its a lost cause and after 130k hard miles its time for a new tranny