Shifting into gear does not engage auto trans

[Evilsmith]

I had to rebuild my motor due to the engine repeatedly blowing head gaskets. Prior to removal the transmission was very strong and ran great. I just got everything together and attempted to take it for a test drive, but when I shift into gear the trans makes no attempt to engage. I made sure it was full of fluid, but I did notice that some of the fluid in the torque converter spilled out when I was installing the motor. The Bently is somewhat misleading and eludes to the torque converter being filled by filling the transmission. However, im somewhat at a loss as to how it would do this when its on the outside of the input shaft. Also, the shift linkage is slightly off, but not enough to cause the motor to not engage at all. My question is this:

1. If it is due to a lack of fluid in the torque converter, how easy it is to manually fill it (Quick rundown of steps if possible would be appreciated)

2. If its not due to a lack of fluid in the torque converter, what could be some other possible culprits?

Again, keep in mind that this transmission showed absolutely no signs of wearing out, although I did take the pan off to put in a filter and new pan gasket. Any help would be greatly appreciated, its crunch time for my Bimmerfest project :(

[whodwho]

If the fluid is showing on the dip stick then you most likely didn't have the torque converter fully inserted and broke the front pump gear. It is a REALLY common problem if you don't know about it.

Did you have to pull the engine and trans together with the bell housing bolts?

[Evilsmith]

When I put the torque converter on it clicked in three times, I tried to click it in a fourth but it really didnt look like it could go back any further. When I put the engine and trans together I first tried to tighten it with the bell-housing bolts, torque converter on the engine, turning the output shaft to click it into place. It didnt work so I put the torque converter on the trans and shook it till it mated to the engine, but I felt through the starter hole and inspection cover hole on bottom to make sure it wouldnt click in anymore.

[Evilsmith]

Got the transmission out in about 5 hours after taking off the pan and checking the filter, the oil pump teeth were sitting in the bottom of the shaft. I have a couple additional questions for you if I may pick your brain:

1. When I unbolted the torque converter from the torque plate (When the trans was still in the car), I took a screwdriver and pushed on it, and it moved a couple inches forward. I know I put it in three clicks the first time because I took it off and checked twice. This means that there is somehow about 1/4 to 1/2 an inch of play between the torque plate and the torque converter. Is it possible that I put something on wrong? (Such as the flywheel on backwards?)

2. Since the pump wasnt pumping oil to engage the clutch disks, is it safe to assume that the clutches are still good since there was no oil pressure to run the transmission at all?

[whodwho]

It is very easy for the TC to slip back out when wrestling the tranny back in. just put the new pump gear in and the TC back in making sure to insert it far as it goes.

Make sure that when you are putting the tranny back in that the motor and trans go together flush without any gap and without pulling together with the bolts. You can verify the TC is fully in by making sure that it can still turn when the tranny is bolted up and has a gap from TC to flex plate like when you first unbolted it and pushed on it with the screwdriver when it was still in the car the first time.

[Evilsmith]

Thanks for your reply. I managed to find a trans mechanic who showed me hwo to break it apart and check everything. Changed out the oil pump in about two hours for $100, worked till 3AM to get the trans installed. Car isnt on the ground yet but the tires are spinning and its taking fluid. Fingers crossed.

[gasgasrider]

Sorry for the late reply but these ZF automatics are known for weak input shaft seals, which when [not if] they fail will cause low pressure to the first gear clutch pak and result in burning it up from slippage. They are easy to change, when the tranny is out of course, and will make a much bad mouthed but good trans into a better one. Every time I take an auto out it gets the seal kit and new fiber plates for that clutch pak need it or not. Cheap insurance...