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Old October 5th, 2006, 05:30 PM   #3
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well, you've the notorious A4LD.....that trans blows balls,'s very very week and notorious for blowing the pump seals and sucking in thing that helps these tranny's last is driving in drive unless you actually need OD - this uses a band to hold the overdrive drum instead of a multiple disc clutch which is much stronger...but back to your issue

First, are you sure you don't have OD or is it that you dont have TCC lock up?

TCC lock up is controlled by the following:
# Application of brakes (Brake switch located on the pedal assy)
# Closed throttle (TPS)
# Cold engine (ECT)
# Very heavy/wide open throttle (TPS and MAF)
# Low engine speed to minimize lugging boom
# 23.5 inches of mercury absolute barometric pressure or below in the intake manifold. (calculated from MAF)

Most of these will inhibit OD shifting as well, and other things such as a vacuum leak (if it's large eneough)

If you dont have OD, your no OD shift could be caused either by an electrical problem or mechanical problem (inside tranny)....I can't remember exactly what's needed to allow the OD shift (electronically) without looking at a diagram. Also, the kickdown cable could possibly be stuck inhibiting OD operation as well.....

If it were me, first I'd check the input to the OD solenoid while driving it - you can do this with a DVOM back probing the correct wire on the trans and routing it into the vehcile. If it's getting 12v at the correct time, all the inputs are good and the issue is something inside the trans (solenoid/seal/clutches worn out). If not, it's an elec issue such as a break in the wire down to the trans (unlikely), a bad input to the PCM, etc.....

Basically, I know it sucks, but you need a manual and some good diag skills....

Last edited by chris1044; October 5th, 2006 at 05:34 PM.
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