How do you replace a transmission in 1997 Chevy Venture?

Answer 1

This is a very big job, and possibly beyond the scope of many shadetree mechanics. You'll need two floor jacks, lots of 1/2" drive metric tools and other special tools, and I recommend investing in a Haynes manual, or the GM service manual. A transmission jack is helpful also. It can be done without an engine support fixture with a little careful planning and work.

Remove the air intake tube and filter element. Disconnect the shifter cable and mount. Disconnect the wire harness from the top of the transmission, and unplug the wire terminals from the selector switch. Remove all the bolts from the transmission case from above. The front two are studs with nuts on them, also used to attach the negative battery cable and other grounds. Remove the nuts and then the studs. The other bolts are felt rather than seen, and they are located up high underneath the exhaust crossover pipe.

The fun part begins: Use a 4 x 4 piece of lumber cut to length, or a very heavy length of steel pipe or square tubing, and a couple of 2 x 4 scraps cut at angles, to run the 4 x 4 across in between the fenders, being careful not to damage the paint on the fenders. Attach a heavy chain to the left rear engine lift hook, loop the chain over the 4 x 4, and bolt it to the right front engine lift hook, making the chain as tight as possible. The engine will hang from this, so it needs to be sturdy. It would possibly be easier to run a much shorter scrap of 2 x 4 from front to back instead of a 4 x 4 from side to side, but I wanted to be sure not to damage the top of the cowl, at the center of the lower edge of the windshield.

Remove the large nuts from the drive axles. Remove both front wheels. Support the van securely on jack stands or blocks. Remove the front valance, and the panels inside both wheel houses. Disassemble brakes, leave the lines connected, use a coat hanger wire to tie the calipers up high out of the way, to the strut on each side. Unplug the ABS wire connectors. Remove the two large nuts from the top of the steering knuckle on each side. Do not remove the bolts yet. Remove cotter pin and nut from tie rod, use ball joint separator, pickle fork and a hammer, or other tool to separate the tie rod from the knuckle. Turn the knuckle, remove cotter pin, nut, and separate lower ball joint. (a spring compressor or strut compressor is not necessary). Using a big hammer and a punch, knock the bolts out of the top of the steering knuckle for removal.

Use a large screwdriver to pry between the transmission casing and the yoke to remove the drive axle. The passenger side is not easy to pry out, but a hammer can be used on the clover-shaped CV yoke to gently tap it out of the passenger side. Note the condition/location of the drive axle retainers, the passenger side retainer stays on the axle, and the driver side stays on the spline shaft in the transmission. Make sure you know if these are in place before re-installing the drive axles later. It'll go together without them, and actually stay that way-for a very short time.

Remove the two bolts and nuts that attach the steering rack to the front subframe. Use the heavy wire to tie the rack up underneath to leave it attached to the van, the hoses and steering shaft shall remain connected. Disconnect the transmission cooler lines, drain. Remove the pan and drain. Re-install the pan with a couple of bolts to make the transmission easier to handle on the jack.

Remove the dust shield from the torque converter access area. Remove the starter. Remove the three bolts from the torque converter.

From the passenger side, remove the mount from the transmission case to the engine. Remove both nuts from the bottom of the sub frame under the engine mount. Remove both nuts from under the driver side transmission mount.

Remove the heat shield from the rear center of the sub frame. Double check for any wire connectors. Disconnect the Power Steering cooler line mounts from the sub frame, (don't disconnect the lines themselves).

Using one floor jack on each side to support the sub frame, remove the four 18mm bolts from the front and back of the sub frame on both sides. A helper comes in handy for this stage. Lower them slowly, watching for anything that might still be connected.

Install the transmission jack in the center area of the pan. Raise just slightly. Remove the last bolt that attaches the transmission to the engine block, this is located behind the passenger side transmission mount, the bolt is reached from the passenger side with a long extension. Remove it, and lower the transmission carefully.