Th350 transmission rebuild manual pdf download

Be sure that the snap ring is fully seated. Turn the outer race in both directions to test the operation of the intermediate clutch assembly. It should turn freely counterclockwise, then lock solid when turned clockwise. Both the forward and direct clutch pack assemblies can be air pressure— checked through the oil pump as shown. Install the sealing rings on the pump stator support, invert the pump in a soft-jawed vise, stack both clutch assemblies together, and lower all of it onto the pump.

Apply compressed air through the oil supply passages and listen for the clutch apply as well as air leaks. Carefully lower the direct clutch assembly into the case. Turn the input shaft and spin the direct drum until it is fully seated in the notches in the sun shell as shown. Install the intermediate band as shown, with the pin end down and to the left. Slip the band over the direct drum and align it with the notch in the case.

Be sure that the band is fully engaged in the notch as shown. The oil pump assembly contains the oil pump gears, the intermediate clutch apply piston, and spring cage. The hub end also has the sealing rings for the direct and forward clutch assemblies.

Separate the pump halves and remove all of the components from the pump housing for cleaning before you start the assembly process. Unhook the ends on all four sealing rings. Remove the four sealing rings from the grooves in the pump support. Remove the thrust washer and any shims under it. A Torrington bearing is used on later units as shown.

Most early units use a tanged thrust bearing here. During removal, take note of any shims under the bearing or the thrust washer. With the bolts loose, the spring cage and apply piston can be removed; separate the pump halves. Lift the intermediate apply piston out of the oil pump housing. Note that both the inner and outer lip seals face down toward the pump. Clean all of the pump parts and place them on a clean surface.

Use a sharp tapered punch to remove the front seal. Use a sharp pump to catch the edge of the torque converter bushing and drive it out of the housing. Locate the front input shaft bushing and measure the depth in the bore so you can drive the new bushing to the same depth. Repeat this procedure for the two lower bushings.

Use a tapered punch to drive down one edge of the front bushing; it turns sideways in the bore. Repeat this procedure for both lower bushings. Remove the two lower bushings in the same manner as the front bushing. The lower bushings turn sideways in the bore.

Pry them out as shown. Drive two new bushings into the lower end of the stator. Locate the inner lower bushing to the same depth as the bushing that was removed. It should be just below the oil supply hole, not blocking it. Drive in a new front bushing. Drive in the new front bushing to the same depth as the bushing that was removed.

If you do not have a spare shaft, you can use the forward clutch assembly for this purpose. Always install a new torque converter bushing for any level of rebuild. Doing so ensures correct alignment of the torque converter drive hub in the oil pump inner gear, which reduces side loading and improves front seal life.

Drive in a new torque converter bushing. Drive in a new front seal. Note that a spring is inside the seal lip. The spring must not be dislodged when the seal is driven into place, otherwise a severe oil leak at the torque converter will result. Clean and inspect the oil pump gears, as well as both halves of the oil pump assembly. Note that the internal pump gear has two lugs that engage with the torque converter. These lugs must be installed toward the rear of the transmission, or farthest away from the torque converter hub.

Failure to do so results in pump breakage and transmission failure. Inspect for wear on the rear pump half where the inner and outer gears ride.

Minor scratches are okay, but deep grooves here are not acceptable. Lubricate the oil pump and gears prior to assembly.

Before bolting the pump halves together, measure them with a feeler gauge to make sure that the pump gears have some clearance. This should not be a problem unless a service replacement set of gears are used, or gears were taken from another oil pump. Place two new seals on the intermediate apply piston, lips facing down. Use a lip seal tool to install the apply piston into the housing; make sure it is fully seated and turns freely.

Install the spring cage over the apply piston. Install the oil pump band and tighten with a large flat-blade screwdriver. Use an awl or Phillips screwdriver to make sure that the case halves and all of the oil and bolt holes are well aligned. Install the intermediate clutch pack into the case. Start with the thick factory backing plate.

Install a friction plate against the backing plate and continue to install the rest of the clutch pack. Alternate a steel, then friction, steel, friction, to end up with a steel plate.

Note that all of the steels for the intermediate clutch pack have a notch as shown, which is installed in the lower right of the case. Place the waved apply spacer on top of the apply plate. Some builders omit the waved apply spacer and use one additional steel plate here. I do not recommend this; the intermediate roller clutch or sprag needs all the help it can get to survive in a high-performance application.

The intermediate clutch pack is now installed. Note the depth of the last friction on the outer race. Install any shims that were removed from under the pump thrust washer. Install it as shown, with the housing facing up or toward the rear of the transmission. Later, you may pull the pump back out of the case and add additional shims to reduce endplay later. Install the Torrington thrust bearing over the factory shim.

Be sure to install it as shown, with the housing facing up or toward the rear of the transmission. Early units used a thrust washer at this location. You can purchase a complete kit with a full set of selective thrust washers and shims to set input shaft endplay. Install the pump sealing rings. Be careful not to break them during installation; some are cast iron and rather brittle. Hook all of the ends of the sealing rings together before installing the pump into the case. Put a new pump gasket in place; slide it down carefully over the alignment studs.

Lower the pump assembly carefully onto the alignment studs. Lubricate the outer rubber seal and sealing rings with clean ATF. Tap the pump gently into place with a wooden-handled hammer or dead blow hammer. Do not force the pump into the case. Install new sealing washers on the pump bolts.

Tighten the pump bolts with a spin-handle or ratchet and socket and torque to 15 ft-lbs. Once the pump is tightened, check the input shaftendplay. Use a small awl or screwdriver to pry upward on the input shaft as shown. Shaft endplay should be. Carefully inspect the speedometer drive gear for wear and cracks. Place the speedometer drive gear retainer on the output shaft. Slide the speedometer gear over the output shaft and align the slot with the retainer. Slide the speedometer gear over the retainer.

Make sure that the retainer snaps over the end of the gear as shown. Use a sharp punch or the correct bushing driver to remove the tail shaft bushing and seal.

Install the new bushing with a suitable driver. Drive a new seal into place. Almost any driver larger than the seal works for this purpose. Install the case to tail housing seal as shown. Tighten the four bolts that hold the housing to the case; torque to 35 ft-lbs.

Locate all of the parts for the speedometer housing. Remove the O-ring on the housing as well as inner seal and retaining ring. Install the O-ring on the housing. Install the inner seal with the lip facing toward the gear. Install the inner seal retaining ring. Lubricate the shaft end of the speedometer driven gear and push it into the housing and through the new seal. Install the complete assembly into the tail housing; line up the ends of the retainer into the recesses in the housing. Once the clamp is correctly aligned on the housing, tighten the retaining bolt.

Locate the governor, governor housing, and retainer. Inspect the governor gear closely for wear or damage. Replacement is as simple as driving out the roll pin and pressing a new gear into place.

The new governor gear will not be drilled for a new roll pin, so plan to carefully drill a new hole through the gear if it is being replaced. Check the governor weights and springs, and see that the plunger moves freely. There is usually no need to take the governor apart for cleaning or to replace the gear; just be sure that it is not damaged and all of its parts move freely.

Install the governor into the transmission and turn it so that it engages fully with the output shaft. Install a new seal on the governor cover. Gently drive the governor cover in place. It can be started and squared up with a few taps from a soft-faced mallet.

Finish driving the governor cover into place with a flat-faced punch. Check that the governor cover is fully seated. Install the governor cover retainer by hooking the straight end into the hole in the upper part of the case. Locate the accumulator and its components. Cut the seals with a sharp pocketknife, scribe, or awl to remove them. Most rebuild kits come with the hook-end metal sealing rings shown. Replace the lower seal with a metal ring and hook the ends together.

Replace the upper ring in the same manner as the lower ring. Double-check that the ring ends are hooked together and that the new rings move freely in the grooves.

Lubricate the case bores and the accumulator seals with clean ATF. Install the accumulator into the case. Install the accumulator spring. Install the accumulator cover with a new seal on it. Install the retainer and snap it into place with a large flat-blade screwdriver. Use a suitable driver to install the manual shaft seal into the case.

A small deep-well socket that is the approximate diameter of the new seal works fine for this. Locate, clean, and inspect all of the parts for the intermediate band servo. Install a new hooked sealing ring on the intermediate band servo piston in the same manner as for the accumulator. Install the washer and pin as shown. Next, install the return spring and retainer as shown.

Place the return spring and retainer into the bore in the case. Lubricate the sealing ring and pump bore with clean ATF. Do not force the piston into the bore or you may break the sealing ring.

It should push into place with gentle hand pressure. Push the band apply servo to the bottom of the bore and observe the band apply through the hole in the case as shown. Locate and clean the parts for the manual shaft installation. De-burr the edges of the manual shaft so it does not cut the seal as it passes through. The alignment of the transmission is done by two metal pins sticking out of the rear of the engine block; the 6 bolts hold the trans straight against the engine block.

Also: remove the engine distributor cap before removing the transmission. BUT: If your transmission had any crud in it, so does your converter, and there is no way to ever get it all out now. Eventually, that crud will be pumped out into the new transmission. Also: -- check the shiny chrome part of it that plugs into the front of the transmission.

Inspect for wear where it has been spinning in the pump bushing. The gear you feel should turn only in one direction, not both. If the trans died because a shaft broke, and there is no clutch material or anything in the pan, maybe you can use the old converter.

Otherwise, it is usually best to replace the torque converter with a new one or with a properly rebuilt one. Nobody guarantees a rebuild when using an old converter. The direct drum and the forward drum from an 8-cylinder model have shorter pistons in them, allowing an extra clutch plate each, spreading the wear over more clutch material, making it more heavy-duty.

It is easy to make this upgrade. A special tool helps to install it. What could I have done wrong in the installation? Kick-down cable adjusted too tight 2.

Not proper intake-manifold vacumn to modulator 3. Supplies needed for a rebuild: assembly lube rebuild kit and any needed hard-parts kits are available locally quick; I do not sell parts, however, I keep on-hand small clips and several other things sometimes lost during the process! Slightly later shifts are popular for when towing or carrying a heavy load, keeping the transmission in the lower gears for a few extra miles per hour. If you get a drop of transmission fluid when you pull the rubber hose off of this left end, the modulator is bad and it is letting trans fluid be sucked up into the intake manifold.

It will work with less, I wouldn't go less than. Stock 4 piston direct piston vs. Next, HD applications should also get a hardened intermediate sprag race.

It is darker colored than a stock piece. The intermediate sprag race and intermediate sprag actually roller clutch take a brutal amount of force on a shift at high rpm. Even more so with harsher shift calibrations. It is the weakest single part of a TH My theory on a long lived setup is that the springs that force the rollers against the race must be in good condition to helps the rollers grab quicker and more evenly on apply. The parts go on the direct drum. The direct drum should use a wider bushing even on stock rebuilds.

Most bushing kits include the wide one. Last edited: May 21, Jun 3, 5. Also check the inside bore of the drum for wear from the sealing rings.

A small amount of wear can be honed out. Visual shiny spots with no detectable wear are OK. Next you will install the direct piston lip seals, and install the piston in the drum. Take note of the orientation of the seals, the lip will face towards the "oil" side of the piston, not the clutch side. Also take note, this is a hi-performace TH and I did NOT install a lip seal in the drum that would seperate the two halves of the direct piston. This is part of the process of "dual-feeding" the direct clutches.

On a stock rebuild you would normall install this lip seal. You can do this on any rebuild but you must also block a passage in the case near the pump to prevent loss of pressure to the reverse circuit. Dual feeding doubles the area of the piston that has pressurized fluid on it in 3rd gear, more than doubling the capacity of the clutch.

It is accomplished by most valve body kits without doing so internally but requires a "transfer" plate and gasket to be added under the support plate in front of the valve body. I prefer internally dual feeding because it leave out the additional gasket and eliminates that one extra possibility for a pressure loss resulting in burnt 3rd gear clutches Yes it has happened to me.

All transbrakes will require dual feed of the direct clutch, as well as many manual valve bodies. Here is the passage that must be blocked. I then slot the head of the bolt so I can use a flat-tip screwdriver. I don't thread the passage completely to bottom. I want the "plug" to seat on the unthreaded portion. Also of note, if you are using almost any aftermarket kit, these kits use a feed plate between the support plate in front of the valve body and the seperator plate.

This feed plate dual feeds the directs and plugging this hole is unnecessary. Also most manual valve bodies, trans-brakes, etc will have you omit the direct drum center seal and the sealing ring on the stator but plugging of this hole is also unnecessary due to the design of the seperator plate. Don't assume you need to plug this hole. Only plug this hole if you plan on building a unit yourself. You can omit the center seal, plug this passage, enlarge the 2nd and 3rd feed holes in the stock seperator plate and you will have greatly increased the torque capacity of a stock TH as well as gained a firmer shift.

Even firmer shifts can be accomplished with checkball removal and modifications to the accumulators. I recommend NOT modifying the accumulator. Retain the cushion spring and do not block the circuit. The accumulator can be blocked by several methods. Removing the accumulator spring and using a spacer nut, washers, cut down section of tubing between the piston and the e-clip is the "shadetree' method. You can also block the feed in the valve body to the accumulator. Jun 3, 6.

Set it in the drum, and it will force the lip seal into the drum without using a tool around the entire circumference. You may however need to work the exposed part of the seal into the drum with the feeler gauge or seal tool. Use care using the lip seal tool, I use a push-in technique more than a work around the drum technique. If you slide around the drum, and it catches the seal it will cut it and then you must get a new lip seal and start again.

Good lighting, patience, and technique are key here, oh, and a good air check Once you have the piston seated in the drum you can install the return springs and retainer. You can buy or make a tool similar to the one pictured or use 5" or larger c-clamps much more of a PITA. Forward drum procedures are almost identical.

No center seal to worry about on a TH, it typically already has a 5 clutch pack, except light duty applications. Forward clutch pack clearances can be tighter than usual, however it must have some clearance.