Notice the open line in the gasket that will parallel the support plate that bolts on at front of the valve body. Locate all of the parts for the speedometer housing. Lubricate the sealing ring and pump bore with clean ATF. Install the pump sealing rings. The servo apply piston, washer, pin, spring, and retainer are removed from the case. The governor slides right out of the transmission. In the case of this switch, you can either leave it in place, unused- or remove it and plug the port. The ber gasket is preferred over rubber or cork gaskets. Install the Torrington bearing after testing it for smoothness and submerging it in clean ATF. Inspect the inner and outer race surfaces closely. 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. Written by Cliff Ruggles and Posted with Permission of CarTechBooks. Unlike lesser engines, the evolution of the big-block Chevy can be traced back to a prestigious great-great-grand pappy, the high-performance 425-hp L78 396, first available in 1965 Corvettes and Chevelles. Bushings are critical in that they allow the rotating parts to ride true on center, and for the lube to make it to the rear of the trans. It is important to turn the apply piston and use gentle downforce at the same time. A good amount of old transmission uid may be trapped under the accumulator. . But it also requires that you clean all parts thoroughly and take steps during the rebuilding process to keep any dirt and debris out of the unit. The intermediate roller clutch, or sprag assembly is attached to the front of the drum, and engaged with the intermediate friction plates in the forward part of the case. Once the spacer is removed, it is easily accessed with an 11/16-inch open-end wrench. I address each part individually as I proceed with the assembly. Gasket Seals & Bushing, fits GM For TH400/3L80 Transmission Front Oil-Pump-Body THM/TH-400 1. Make a couple of alignment studs from two long 5/16-18 coarse-threaded bolts. The stock thrust washer was probably plastic; the replacement should be metal. Install the inner race for the low-roller clutch. This allows reverse when applied simultaneously with the direct (high gear) clutches, and allows manual low gear when applied with the forward clutches. Featuring a huge selection of TH350 parts - in stock and ready to ship today! 1-2 Accumulator Piston Cover Kit 35988-01K. This causes undue wear on the internal transmission parts, rear differential and axles, drive line and u-joints. This spring occasionally breaks and requires replacement. . A later-model spring cage is shown with the springs attached to the cage. May consider use of teflon bushing, only a lubrication passage, no pressure, no lateral loading. Locate a suitable driver to install the low-planetary bushing. Also most manual valve bodies, trans-brakes, etc. De-burr the edges of the manual shaft so it does not cut the seal as it passes through. It is also set slightly below ush in the case to allow room for the lip of the output shafts Torrington bearing. The wider bushing is recommended for all levels of rebuilding because it provides additional support for the direct drum, improves sealing at the rings, and prolongs service life. A scribe or hook makes removing these components much easier. Because the input shaft is attached to the forward drum, it should be left in place during the rebuilding process. Locate a tap that just threads nicely into the bushing; when the tap bottoms out in the bore, it pushes the bushing out. Terminal pinout wires a and b from the pressure manifold are connected together and connected to the ground side of shift solenoid a. . A TH350 is known to be rough on bushings. Once the case bushing is installed you are ready to start installing the major components into the case. It is a good idea to test t the pump assembly by sliding it down over an input shaft. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Customer Reviews, including Product Star Ratings help customers to learn more about the product and decide whether it is the right product for them. Then install the 3-tang thrust washer onto the top ring gear. Most shift kits come with upgraded separator plate gaskets (right). This is part of the process of "dual-feeding" the direct clutches. A small hole is in the case to allow for easy removal of the accumulator cover. Use a rubber tipped air nozzle to apply air to the passages around the pump circumference. Summit Racing will BEAT any competitor's advertised price! Bellhousings. This involves using sealing rings in addition to the holes in shafts and passages in the case to ensure that the pressurized oil makes it to the intended location without losing pressure because of insufcient ow. Lower the pump assembly carefully onto the alignment studs. They do not interchange during the rebuild without changing to a different style planetary gear that accommodates the tanged thrust washer. Clamp the halves with a band clamp and tighten the bolts nger tight. Install the bushing in the output shaft. Install the oil pump pressure screen/lter into the case. The TH350 is a rugged and durable unit, and fairly simple in construction and operation as far as automatic transmissions are concerned. There are thicker intermediate steel plates available if need to tighten up the clutch pack clearance. Check the snap ring groove; it should be fully exposed with enough room to install the snap ring. It is somewhat difcult to access after the transmission is installed in the vehicle, so you want to replace it during rebuilding if it shows wear or damage. Center the spring compressor in the bore of the case so that both arms distribute the load evenly to the spring cage. A notch references the location of the steel in the case, even though they only install one way. A large nut retains the shift linkage (rooster comb)to the manual shaft. Bushings are critical in that they allow the rotating parts to ride true on center, and for the lube to make it to the rear of the trans. Then install the small outside snap ring to hold it all in place. 1-2 Accumulator Sleeve Kit 35719-01K. Apply a small amount of red Loctite to all bushings before driving them in place. Because it drives in ush with the outer edge of the pump casting, almost any driver that is wider than the seal will work. Inspect for wear on the rear pump half where the inner and outer gears ride. Once the snap ring clears the case lugs reach in with your free hand to pull it right out of the case. Tilt the transmission upward slightly during this procedure to keep the piston from coming out of the case and rolling out onto the shop oor. International Customer Options|In the United States? $110. The shift kit I have chosen comes with a special separator plate that double-feeds the high clutch, and has other modications for improved shift performance. You need to clean the case well enough to locate any cracks prior to assembly. Flip the sun shell over and drive out the lower bushing. Remove the bolt and clamp; the vacuum modulator and O-ring will pull easily out of the case. Drive in a new front seal. 1 . If too tight it can creep in neutral. The direct drum is located behind the oil pump assembly. Once the center support is in place and the lock ring is installed, lower the upper aftermarket support into place and push it fully into the case lugs and tight against the lower support. There are Alto red frictions in this unit, however a stock tan clutch ( like Borg Warner brand) is more than adequate for even very high HP cars. Locate the 1-2 accumulator and its components. You ended with a waved apply spacer that has one at steel under it. You can copy and paste this link to share: https://www.chevydiy.com/gm-turbo-350-transmission-installation-guide/. If endplay is beyond .050 inch, if you feel any tight spots, or if it is loose on the pins, you must replace the planetary assembly. Drive in a new front bushing. Ready for intermediate pressure plate install. A Torrington bearing is used on later units as shown. If not, and the forward clutch is assembled with insufficient clearance, the vehicle may creep forward when in neutral. Clean all of the components of the direct drum. Even so, they seldom give any trouble. Be sure that the band is fully engaged in the notch as shown. You can buy or make a tool similar to the one pictured below, or use several 5" or larger C-clamps. Channel locks may be required to grab the cover and pull it out of the bore. Keep them in their original conguration for the clutch count. Notice how the retaining spring also loads the center support against the case lugs, and how much clearance is present. Prior to removing the oil pump, it is a good idea to take an input shaft endplay reading. Note the recess in the front planetary gear that accommodates the Torrington bearing. Make sure that the ends of the snap ring are between the raised areas of the spring cage. Inspect the pinions for damage and endplay, as you did with the low-planetary assembly. See each listing for international shipping options and costs. Most TH350s use four friction plates and four flat-steel plates. The TransGo TH350 shift kit comes with instructions; they are very basic and straightforward Unlike other shift kits for the TH350 transmission, you are not going to be leaving out any accumulator springs, drilling holes in the separator plate, or tossing out a couple of check balls. Just click the "edit" tab at the top of this page, or click one of the [edit] links to the right of an article section. Grasp the servo assembly by the apply pin and remove it from the case. Finish driving the governor cover into place with a flat-faced punch. Replace the bushing in this planet.Check planet pinion gears for side to side movement. Locate and install the new lip seals for the forward apply piston. This unit uses a spring cage with all of the springs attached to it. Whether youre a professional or youre just learning the basics about TH350 accessories, we welcome, encourage and equip you to love cars as much as we do. It helps to push one side down and then walk it around the end of the shaft while pushing it down into the retaining groove. With the early type you had to manually place the loose springs onto the piston's spring locator bosses,then the retainer went over that. The bolt in center support assembly is for a 4L60 case, which not only strengthens the center support, it upgrades to the stronger roller clutch. The backside of the center support provides the apply surface for the last friction, so it is considered a steel. Ive seen a few TH350 cases cracked in the bellhousing area. A Hi-Energy Borg from a 4L60E is also a good choice. Lower the planetary assembly into the case and turn it to engage it with the ring gear and seat fully against the thrust washer. Slide the tail housing off the case and over the output shaft. 3 popular books for rebuilding 350s: Th350 Th400 700r4 Transmission Valve Body Check Ball Steel .250 Inch 10 Pieces. Most rebuild kits come with new screens; if not, the old ones can be cleaned, blown dry with compressed air, and reused. Remove the four sealing rings from the grooves in the pump support. Remove the backing plate, frictions, and steel plates. Ensure the lugs of the direct drum are engaged with the sun shell. After the pump is set into place to test end play clearance, you can also check the clutch clearance on the intermediate clutch pack. A quick test t on the output shaft veries correct bushing installation. Inspect the governor gear closely for wear or damage. Transbrake Valve Body TH350 (1) $540.00. Loosen and remove the ve pump bolts. Install the new bushing to the depth as shown in the pictures. Be sure to always look on the bottom of each piece as you remove it; its quite common for thrust washers to stick to the component being removed and not be present on the next component in the case. The spool valve slides out of the valve body when it is removed. Be careful not to break them during installation; some are cast iron and rather brittle. A longer 4x4 output shaft was used for around 1.5 years. Once the case has been cleaned, all threads checked and/or repaired, and the rear case bushing installed you can start assembly. Please check compatibility before purchasing. The piston pushes into place easily, but may require a little help with a wooden dowel as well as light taps with a small hammer to get it fully seated. The head of the bolt can be slotted so a screwdrive can be used. This can be accomplished on a brake lathe. These HD bands should have welded reinforced band struts as show in photo. Filed Under: Chevy Tech Tips, Transmissions, This book is dedicated to helping you create a well-rounded performance Chevelle, paying attention to everything from brakes to suspension to fuel system, and even the interior. Check the endplay on each pinion as shown. If you need one email me and if you can supply a core, I MAY be able to sell you a piston. https://www.crankshaftcoalition.com/wiki/index.php?title=TH350_rebuild_tech&oldid=1602289. Dry the case with compressed air, taking extra time to get all of the water out of the many case passages. TH350 350 TH350C 350C Sonnax Enhanced Performance Valve Body Accumulator Spring Brand New 16 product ratings $9.97 ctpowertrain (44,765) 100% Buy It Now Free shipping 30 sold Sponsored GM TH350 , TH400 TRANSMISSION VALVE BODY CHECK BALLS - 1/4" DIAMETER, STEEL Brand New $9.50 Save up to 15% when you buy more Buy It Now boundlessv (6,404) 100% Note how much longer the rollers are on the aftermarket part. Use a sharp punch to drive out the upper bushing inside the sun gear. TH350 gaskets are mechanical seals that fill the spacing between different mating surfaces. This page was last modified on 10 May 2017, at 09:23. Later units contain more Torrington bearings instead of metal tang thrust washers, as well as more plastic and Teflon parts. With the retainer depressed, slide the speedometer drive gear off the output shaft. It also analyzed reviews to verify trustworthiness. Locate the governor, governor housing, and retainer. Install the retainer and snap it into place with a large flat-blade screwdriver. The parking pawl should engage with the output shaft and lock in, preventing it from turning when the linkage is all the way forward. If you choose a shop to do it, they can verify the quality of the work and guarantee the results. Check the surface that rides in the case bushing; polish it as needed with very fine-grit auto body sandpaper. Be sure to also check the case very closely for cracks. Locate the low/reverse frictions. general motors turbo hydramatic 350,TH350,turbo 350, help you build,turbo350,thm350. Grid Once the case is cleaned and securely mounted in the holding xture, drive out the case bushing. They do not need to be removed to get the linkage out. Install the snap ring to retain the spring cage, and make sure that the opening in the snap ring does not line up with the raised areas of the cage. These units can cost $300.00 or more. Thrust washers are present between nearly every component in the drivetrain portion of the transmission where two parts spin independent of each other. Drums installed in the transmission case. The bushing is driven in ush. Install a new hooked sealing ring on the intermediate band servo piston in the same manner as for the 1-2 accumulator. Copyright 2023 by AUTOSALES, INCORPORATED Building a strong transmission that will provide many years of reliable service starts with using a good core. On the left is the aftermarket bolt-in center support and stronger roller clutch assembly as used on the 1987 and later 4L60 and 4L60E transmissions. Be sure to blow out any chips left by the bushing-removal process from the output shaft bore and oil holes. Install the intermediate clutch outer race. Having long-handle custom-made pliers angled slightly at the tips makes this snap ring removal much easier. There is a lot of load on this bushing, and it should ALWAYS be replaced on overhaul. Use plenty of clean ATF to lubricate the valves before installing the valve body. Brass screened filter allows for more flow. will call for omitting the direct drum center seal and the sealing ring on the stator, but plugging this hole is also unnecessary due to the design of the separator plate. Reduce clearance of the stack to 0.040". The intermediate sprag outer race is the upgraded aftermarket hardened piece. GM used to use an aluminum piston and then switched to a plastic one. Installing the direct piston will require some patience, a lip seal installed or 0.010" feeler gauge, and a trick to use is a section of plastic cut from a 3 liter soda bottle to use as an outside installer tool. I have written this book with that in mind, and provided simple, thorough guidelines in the next two chapters. Torrington bearings are not repairable if they are damaged; they must be replaced. Your Cost $ 25.30. You may have to push each roller in slightly to get it started. With such high usage of this transmission, the replacement and aftermarket parts for them can easily be found. Insert Quotes Quotes Post Reply. Now is the time to air check the low clutches. Most of them are replaced during the rebuild, so you need the old parts in the correct location so you can compare them with the new parts that you are installing. Might as well order a bushing kit, as well as a thrust washer kit. Turn it and feel for rough spots, which are tight when it turns. Repeat this procedure for both lower bushings. 9/10 Wonderful! accumulator cover tool (or use my tools!) Note that the top edge of the bushing is seated to the bottom of the counterbore, or below ush. Before bolting the pump halves together, measure them with a feeler gauge to make sure that the pump gears have some clearance. Some bushing kits come with a plastic split bushing that you can use instead of the metal bushing. Same also holds true with the oil pump - "C" is cast into the pump cover and pump half. Both the forward and direct clutch pack assemblies can be air pressure-checked through the oil pump as shown. Shaft endplay should be .015 to .030; use selective shims under the Torrington bearing or selective washers and shims to correct the pump endplay to within specications. 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The modulator on the transmission will raise the main line pressure in the transmission. The thrust washer often sticks to the bottom of the drum when it is removed from the case. Apply a small amount of red Loctite to the new bushing and drive it into place. Its not uncommon for the O-ring to stay in the case as it did here. It should be .040 to .060 inch. Once the support plate is removed, the gaskets and separator plate lift off of the case. While trying to replace the 2-3 Accumulator Piston in the valve body it broke. After viewing product detail pages, look here to find an easy way to navigate back to pages you are interested in. Low/Reverse Apply Piston Removal. Note the location of the notch on the steels in the bottom of the case, and that the last friction is very close to the top of the low planetary, although it is still fully engaged. Chrysler Dodge Jeep Shift Kits. Make sure that the retainer snaps over the end of the gear as shown. Skip to content . $5 Off Your $100 Mobile App Purchase - Get the App. Manual low gear creates engine braking on deceleration. This is a custom order part. Minimize trafc in and out of the work area, and use a 55-gallon garbage bag to cover the case when you leave the shop for extended periods of time. You can also see the braking band installed. There are 0 customer reviews and 1 customer rating.