Universal holding fixtures are available that utilize the pan’s bolt holes to attach it to the case. The downside of these fixtures is that they have to be removed to install the transmission’s oil pan.
Roll-around carts also make a great place to lay out rebuild kits, bushing sets, thrust washers, and other items used to rebuild transmissions. They can be pulled right up to the work area without mixing up the new parts with used ones, and then pushed away when cleaning off and blowing parts dry with compressed air.
A shop vise, especially a large one, can be a nice addition to your list of tools for your transmission rebuild. A set of soft jaws can be added to hold shafts without damaging them. You can also use it to hold the valve body when you need a third set of hands to keep it stationary for removing valves, springs, etc.
Although not part of the list of tools for most folks, having a small lathe or access to one helps if you are rebuilding a “max-effort” TH350 transmission. It is also especially useful if you want to increase friction capacity to one of the drums or custom set the endplay for a particular clutch pack by removing some material from the apply piston. Most TH350s show up with a four-clutch-pack direct drum. It is very easily increased to five frictions by removing some material from the apply piston. You can also use a lathe to remove material from the low/reverse apply piston, or forward drum apply piston. You can also use it if you are working with a light-duty TH350 and want to increase the clutch capacity in those drums.
A heavy-duty shop vise is like an extra set of hands and comes in handy for holding components that you are working on. You need a set of soft jaws or couple of wooden blocks when clamping down parts that you don’t want to damage.
Small shop lathes are becoming increasingly popular and part of many hobbyists’ home workshops. If you have a lathe, or have access to one, it can come in very handy for transmission rebuilding. A lathe can be used to spin and polish shafts with very fine auto body sandpaper to remove rust and light pitting or smooth up the surface where it rides in a bushing. A lathe can also be used as shown here, to remove the appropriate amount of material from an apply piston to add an extra steel and friction to a clutch pack. This saves the expense of buying a shorter apply piston when you are beefing up the TH350 for a high-performance application.
Large commercial-grade cookie sheets are great for laying out the internals of the transmission as they are removed from the case. The cookie sheets hold the oil draining from the parts, and keep any small parts, such as check balls, from rolling off onto the floor. Frictions and bands need to be soaked in clean automatic transmission fluid (ATF) for at least 15 minutes prior to assembly. A one-gallon ice cream pail with about a quart of ATF works well for this; they generally have a lid to keep out dirt and debris. ATF also works well for lubricating Torrington bearings, and dipping apply pistons prior to installation in the drums.
Large commercial baking pans keep parts on the bench from rolling off onto the floor. They also hold any fluids draining from removed parts.
You need a container to soak friction and band material prior to installation. One-gallon plastic ice cream buckets work well for this purpose, and their lids keep dirt and debris off the new parts.
Once the transmission is completely stripped down, the case needs to be cleaned. Cases are often coated with mud, dirt, grease, undercoating, and road tar. A quick trip to a local carwash gets rid of most of the heavy debris. Some additional time spent with a screwdriver and small wire brush loosens the stubborn dirt and grease. Some solvent, such as brake cleaner, may be required to get the tar and undercoating off of the case. Brake cleaner also helps to dry the case; it doesn’t leave an oily residue. It also works quite well for cleaning internal components.
A gasket scraper, small screwdriver, and wire brushes also help with case cleaning. They help remove really stubborn deposits such as undercoating and road tar that the transmission has encountered through years of service.
Brake cleaner helps dry and degrease the case prior to assembly. It doesn’t leave any oil or other chemicals behind that could prevent paint from sticking, and it doesn’t damage the rubber seals on the TH350’s low clutch-pack apply piston.
A power washer makes a great transmission case cleaner. Using a zero tip, a good power washer blasts off dirt and grease to make the cleanup process a lot easier.
Dirt can enter the assembly in a lot of places when you are power washing the cases. It’s not really practical to tape up all of the potential entry points to try to keep the water and dirt out prior to power washing, so I usually save the cleaning for after the cases are stripped all the way down. Even so, some common sense applies here, and a case completely covered with mud from a 4x4 or off-road application is certainly one I’d want to clean up some before taking it apart.
Several very good degreasers are available to clean up transmission cases and tail housings that may be covered with dirt and grease. Soak the transmission for several hours and then blast the case with a power washer or take it to a local car wash.
Several companies make heavy-duty degreasers specifically designed for this purpose. Applying these cleaners before power washing or hand cleaning helps to loosen heavy greasy deposits from the case. Some of these products produce fumes so they should be used only in a well-ventilated area. Also use a good pair of thick chemical-resistant gloves.
Bushing Removers and Installers
Automatic transmissions have numerous bushings. Some are relatively easy to access for removal and installation, while others may be quite difficult to get to. If a bushing is readily accessible and driven in flush with the top surface of its hole, removal and installation is relatively easy. Just about any suitable flat driver can be used to flush-mount a bushing.