Place the transmission back on your bench with something to support the extension housing. Hb```"%"A1e W)1m[+*$0M!Q Pkn$SIVbv%y\ex-Df5scm[6a]BL^A^ Td(()QR d`.W }d8 YST9{6LZ> PVW endstream endobj 70 0 obj 225 endobj 53 0 obj << /Type /Page /Parent 48 0 R /Resources 54 0 R /Contents 59 0 R /MediaBox [ 0 0 612 792 ] /CropBox [ 0 0 612 792 ] /Rotate 0 >> endobj 54 0 obj << /ProcSet [ /PDF /Text ] /Font << /F3 56 0 R /F4 61 0 R /F5 63 0 R >> /ExtGState << /GS1 67 0 R >> /ColorSpace << /Cs5 57 0 R /Cs9 58 0 R >> >> endobj 55 0 obj << /Type /FontDescriptor /Ascent 807 /CapHeight 754 /Descent -249 /Flags 262176 /FontBBox [ -140 -261 1195 990 ] /FontName /CCKOCC+Futura-CondensedBold /ItalicAngle 0 /StemV 141 /XHeight 505 /CharSet (/C/three/R/F/D/comma/four/quotedblleft/E/S/G/hyphen/ampersand/quotedblri\ ght/K/U/I/A/six/space/V/seven/parenleft/L/H/M/parenright/one/nine/P/N/O/\ B/T/colon) /FontFile3 65 0 R >> endobj 56 0 obj << /Type /Font /Subtype /Type1 /FirstChar 32 /LastChar 240 /Widths [ 245 246 360 490 490 858 590 250 300 300 376 490 245 318 245 547 490 490 490 490 490 490 490 490 490 490 245 245 490 490 490 454 833 528 479 452 530 392 394 563 555 255 352 513 373 722 573 582 487 582 530 440 414 544 565 793 545 514 508 320 250 320 490 500 300 433 433 315 433 414 299 437 424 209 209 440 210 639 424 436 433 433 315 376 308 423 452 694 489 452 401 300 250 300 490 245 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 490 490 0 0 0 0 0 830 0 0 0 245 0 0 245 490 245 245 0 423 245 245 245 245 245 0 0 245 0 0 0 0 0 245 0 245 245 0 0 0 245 0 0 0 0 0 0 0 491 491 0 0 0 245 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 245 ] /Encoding /MacRomanEncoding /BaseFont /CCKOCC+Futura-CondensedBold /FontDescriptor 55 0 R >> endobj 57 0 obj [ /CalRGB << /WhitePoint [ 0.9505 1 1.089 ] /Gamma [ 2.22221 2.22221 2.22221 ] /Matrix [ 0.4124 0.2126 0.0193 0.3576 0.71519 0.1192 0.1805 0.0722 0.9505 ] >> ] endobj 58 0 obj [ /Separation /All 57 0 R 68 0 R ] endobj 59 0 obj << /Length 1173 /Filter /FlateDecode >> stream The first thing we are going to cover in this installment is transmission Build Date Codes. driven gear, 60) Retainer, Usually the gear and 3-4 synchro hub dislodge if you hold third gear and gently tap on the front of the mainshaft. The midplate is preassembled with the rear bearing. (Part of #25-35), 48) Washer, The last detail is to install the speedometer fitting and speedometer gear. ), 10) Retainer, This image shows the correct relationship between needle bearings, their spacers, and the center tube. It can never be taken for granted that the installation of new parts guarantees a fully functional and problem-free unit. driven, 59) Sleeve, Sometimes the shaft may be stuck in the extension housing. retaining, 20) Sleeve, 3rd & Not for passenger car as some self proclaimed specialists may think. cF Transmission That is both good and [Click here to read more], An intake manifold is about as simple as it gets, right? Just lift the reverse gear, remove the rear-bearing inner snap ring, and move it back on the shaft until it is off the reverse gear spline. gear bearing The first documented Corvettes with the Muncie transmission appear in the May-June time frame. The regular productions codes identify an M-20, M-21, and M-22. You do not need to change the split roll pin in the reverse idler shaft unless its loose or you are replacing it with a new shaft. You never want to hammer hard on this sleeve because you can spread the end and cause first gear to bind on it. Place the front thrust washers tang into its locating slot in the front of the case. to case assy. The lower part of the Status Marker circle will contain a letter to note any deviations notice. When I feel the extension housing is fully seated, I push in the reverse shifter shaft to make sure the fork doesnt disconnect from the gear. 3rd & 4th, 26) Ring, 3rd & This means that you are completely disassembling the gearbox, inspecting all parts and components, replacing worn and damaged parts, installing suitable gaskets and bearings, and then assembling all the components into a complete unit. 1965-72 4 spd. The sidecover alignment dowel is located below the upper right bolt. We provide parts in three separate categories for the Muncie M20 4 Speed: Overhaul kits by application include standard kits, heavy duty kits for more horsepower and "WS" kits that include both bearings and syncro rings as well as gaskets and seal s. IDENTIFICATION - CHEVROLET 4spd, RWD, M20, Muncie, aluminum case, 7 bolt side cover retainer to case Use a bearing cup installer with the drive cone flipped backward to install the bushing. The following six digits were the last six digits of the VIN. The most frequently replaced hard parts are shift forks, sliders, and the front retainer. Chevy Muscle Car Tech Tips, Guides, Articles & How-To. Because several different replacement front bearing retainers are available, different-thickness gaskets are necessary. Always reinstall the spring facing in this direction. extension Use the correct tools and techniques when performing any or all of the procedures. * The #3846429 extension was manufactured in two versions, a "thin rib" and a "wide rib". 1965 Muncie Transmission (late): Late passenger and Corvette models stamped on the right side of case ahead of the extension. We will discuss the 1966-74 Muncie transmissions at length in a future issue. A solid slinger is on the shaft (left) and Im holding a tanged slinger (right). Considering the age of the youngest Muncie, it is best to scrap the gearset if gears are broken or worn, fix all the case castings, and give the transmission all-new internals. Stay up-to-date on our special promotions and deals. muncie 4 speed shifter & linkage, 67-68 camaro 68-72 nova 67 fb. This is not model or year specific. 2nd Synchronizer, 31) Hub, 1st &2nd Free GM M21 4 Speed Parts Schematic. ! Sometimes you can spread the bushing end. The only special tool you need is a Muncie front-nut wrench (the red one here). The side cover date code is usually found near the casting number. CHART *MUNCIE Shaft Identification: Muncie 4-speed transmissions can be distinguishedvfthe rom style of the transmission arm attachment. NVG 4500 I think, made in same plant as the "Muncie 4 speed" back in the day. Place the .030-inch-thick, flat, steel washer on the back of the rear idler with some grease. These rings were put on for the Muncie assembly line workers to readily identify which input shaft they had to install. Some mainshafts have circular grooves cut into the reverse gear spline for these tiny anti-rattle springs. The object is to get the thickest ring in the rear mainshaft snap-ring groove. Switches and Wiring. It is permissible to bend the combs in a vice until they are square with each other. 0 tapered pin that is wider at the top than at the bottom. Let me explain. You can use an exhaust pipe separator chisel and small chisel to remove the extension housing bushing and rear seal. Trans. Once you have adequately tapped on the bushing, the bushing drops right out. %%EOF synchronizer You need to be in second gear to clear the reverse idler case boss. There was only one side cover casting number used during the 1963 and 1964 model year. Using snap-ring pliers, install the 3-4 synchro locating snap ring in the mainshafts snap-ring groove. The main case date code is usually found on the passenger side of the case just below the casting number. They are soft steel and are left-hand threaded. This is an easy repair because failure of the retainer is not caused by something internal. The opposite side of the date marker has between one and five dots, representing the week of the month. Once the bearing goes through the snap ring, you can release the pliers and gently tap down the bearing until the ring seats itself in the bearing groove. Position the reverse shifter shaft forward so it is in reverse. Use grease to place the reverse-gear fork in the lever arm. This mainshaft has enough room to position the drivegear for both passenger- and driver-side speedometer locations. Check for any nicks and deburr all rough edges. Written by Paul Cangialosi and Posted with Permission of CarTechBooks. endstream endobj 150 0 obj <>stream 04 represents the month code when the unit was assembled, April. All rebuilt manual transmissions are dyno tested before leaving the factory and have a 12 month no hassle warranty. These have a tendency to fly off the cover and get lost. endstream endobj 147 0 obj <> endobj 148 0 obj <> endobj 149 0 obj <>stream Within 10 minutes the pin is locked and sealed in place. This information was only useful to the Muncie plant by allowing the tracking of problem parts. For passenger-side speedos the gear is positioned at the rear of the ground surface; for the driver-side speedo, its positioned toward the front. We also discussed the best ways to identify a Muncie, which is by the casting numbers on the external components of the transmission. Pry under the reverse idler gear to remove the gear, thrust washer, and idler shaft. ch says: February 6, 2022 at 2:26 am. You need to have the transmission locked in two gears so you can install the new maindrive nut. A transmission that leaks after a rebuild can be a huge disappointment. 2. & (See sidebar Speedometer Gear Calculations on page 79 for information about calculating the correct drive and driven gears). It can be acceptable for the Status Marker circle to be blank. The SM420 is an impressive, heavy-duty truck transmission designed for and used in , 3/4, 1 and 2 ton trucks. The Muncie four-speed, like the T-10, is a side-loading transmission. (I never have leaks.) bgd&UD!&f_Vmiy0{K? Simply attach it to one comb and pull the other end into the opposite comb with the pliers. It replaced the T10 in General Motors' cars, starting in February of 1963. The following vehicles are likely sources of a Muncie four-speed. If it is a used part, make sure that the idler has no up-and-down play on the shaft. *This transmission is part of a joint-venture between General Motors and Ford Motor Company to split development of two transmissions, a longitudinal 10-speed and transverse 9-speed. Sales & Service Teams now available 7 days a week! [4Uvo*=+3Ume _K^[\9uWl;w3Sm?kw3P/}cWPpn-%PGRJo !Z)qNTEG "sds=6l;SG2d3U"))EIjy+}GJL Posted in Corvette, C1 1953-62, Technical, C2 1963-67, Technical, C3 1968-82 and Technical. Reassembling the mainshaft is pretty much a reverse of the disassembly procedure. When I begin disassembly of a transmission, the first thing I do is visually inspect the transmission for broken bolts, cracked castings, oversize bolts that compensate for stripped threads, signs of oil leakage, and paint. I drive it straight down the shaft until its seated. Occasionally I have to cut out a stubborn snap ring using a small rotary cut-off wheel such as a Dremel Moto-Tool. Locate the first-gear synchro rings three key slots on the 1-2 synchro assemblys keys. You need to use a press and bearing clamp on third gear for removal. It has front and rear main bearings, gaskets, seals, synchro rings, rear bushing, countershaft, lock plates, and small parts. If they are really bad you should change them out. Shifter lever to It helps make your rebuild look more professional. retainer, 13) Ring, Clutch The Muncie has probably been the most popular transmission among the hot rodding set since its inception in 1963. 1st & 2nd, 36) Ring, 1st & 2nd 1963-1966 production codes will start with the letter P and have four numbers, for example: P0421. The Status Marker information was used by the Muncie plant to help track a problem part. lever to shaft Reverse idler front This number is much different than the casting date codes for the individual parts that make up the transmission, which is covered below in the Casting Date Code section. In-exchange for Ford's 10-speed transmission, General Motors will let Ford use its 9-speed transmission for front-wheel drive applications; Ford ultimately declined use of the 9T and instead, removed 1 gear and used the 9T as an 8-speed transmission.[2][3][4]. You will disassemble it later. buy 4 - 4 and get 15% off buy 5 or above and get 20% off . Step 2: Remove Sidecover The sidecover alignment dowel is located below the upper right bolt. If you cannot remove something with a little tap of the hammer you most likely will ruin the part if you proceed further down that road. Notice the way Im gripping the punch while tapping the bearing. Main shaft front, 19) Ring, 3rd & 4th Shifter lever to It is basically correct, and to be used in a 1966 to 1967 Muncie M20 application. The date marker has a month designator for when the part was cast or manufactured. Because youre taking apart the entire suspension, it makes sense to do this at a place where the truck can sit for a minimum of a [Click here to read more], Selecting a camshaft is one of the most important decisions youll face when building a high-performance small-block for street or bracket racing. Remember that nothing smaller than 350 ci is worth building. Fit the thickest ring you can into the groove using snap-ring pliers. Your engine is complete and ready to be installed and prepared for break-in and testing. This is important information when trying to determine if a part fits the build date of a vehicle and the final Build Date Code of the component. Some sets have two .015-inch gaskets that can be stacked. Be sure to pay attention to the position of the countershaft. Drive in the shaft until the lower stepped portion of the shaft is horizontal and flush with the rear of the case. The Muncie was used in all high performance applications until the Borg-Warner Second Design Super T-10 began replacing it in 1974. Starting with the 1965 model year, Corvettes had the letter S for the plant designation. Shifter lever to If the combs are bent they do not run along each other smoothly. Muncie 4-Speed . Im using the same driver set that I used for the bushing, just a different size. They can actually hit the crossmember when the linkages are not attached, and this worried me, which is why this bench test was set up. Once the retainer is installed, clean up excess sealant and bend the lock tabs over. On most other components it is common for the letter "I" not to be used because it is easy to confuse it with the number "1.". OE Replacements. gaskets & seals . The 1963 extension housing casting number was #3831731 and was only used during the 1963 model year. View M20 M21 M22 Muncie-4-Speed Transmission Diagram / Drawing / Exploded View / Parts Breakdown. Thanks Dad! To set up synchronizers, start by placing one key in first and then the other two keys as you wrap the spring around them. The key difference between. The code consists of two circles, both 1/2-inch in diameter and divided in half. Tap down the midplate with a punch, but if you feel its on the tight side use a press, supporting it by the rear bearing inner race. Wipe away any excess sealant. All Muncie transmissions have a ring groove on the input shaft and counter gear. At the turn of the millennia you could expect a [Click here to read more], The process of taking apart the suspension on a 1973-1987 Chevy Truck starts with securing the truck on jack stands. Transmission 3rd Speed. 9 represents the model year. % "v5FiSz:ByFR:HyP^dw?e S( oJ`^b~_ ! P represents the manufacturing plant, Muncie. Remove both shift levers and mark them so they can be replaced in the same bores. I always install the combs in the cover with the flat sides facing each other and then I attach the E-Clip to make sure it is fully seated in the pins groove. New combs are harder and much better than the older ones. Countershaft Combs have a rounded side and a flat side. The early #3846429 extension has the casting numbers cast directly into the part. 2.698 Backup Light Switch Brackets. Then, take your snap ring pliers and . QQtx:ES~U*T.Ly&(6*'? 7s If so, remove it from the extension. Muncie 4 Speed Bearing Retainers Complete Muncie Transmission Units The guys at Anaheim Gear tell us there are seven total Muncie input shaft options. You place the gear in the transmission with this shaft and then use the good shaft to push out the dummy shaft. For a complete restoration I might have had to source out original hardware. Trans. Use snap-ring pliers to spread the rear bearing retaining ring open and then tap the bearing with a hammer to dislodge it from the ring. These grooves were cut into the input shaft so the Muncie assembly line worker could easily identify which input shaft should be installed in a particular unit. Complete Manual Transmissions. This extension has the "wide" or reinforced rib on the bottom. bearing retainer Light tapping should drive the bearing out of the bore. The first character was the last digit of the model year. Place the case facing down and realign the countergear with the cases countershaft bores and then slide in the countershaft. A Dremel or rotary tool is helpful for deburring gears. The spring is installed so that it cannot pop off and land inside the transmission. Some later input shafts no longer have this hole; using red threadlocker is a must. Try to be patient when you come across these rebuilding obstacles. If the pin is really loose, replace the cover. Some have one that is .015-inch and the other is .030-inch thick. Install the input shaft assembly from the inside of the case. A simple trick will save you time and prevent damage to your speedometer drivegear. Use a 9/16 socket and torque the four bolts to 25 ft-lbs. . Muncie 4 Speed Transmission M20, M21 & M22 with 1" counter shaft bore. =7r+`d,v8rG(Kw^\S<>>oooawW,"gf :u# R Reverse shifter Pry near the dowel to remove the cover. The combs must be flat. 3. Flip the driver upside down and gently tap in the seal until it is seated. 4 spd. Place the exhaust pipe separator chisel in the oil return slot. idler shaft lock The location of the VIN stamp can vary but it can usually be found on the top leading edge of the main case or on a mounting surface near the Build Date Code. bearing, 6) Spacer, This parts deals with case preparation.Mu. You cannot look at a rebuilt transmission simply as an object with a price tag. 4. Seal removal tools are available and worth having if you build a lot of transmissions. I use grease to hold it in place. 11/16"), 80) Nut, Shifter clutch, 18) Bearing assy., \;1"89ek5YAwG Rv($|)d Use a 3/8-16 bolt as a tap surface for bolt-on shafts. Pre-1969 Muncies use a stud and nut at the indicated attachment point, while 1969 and later Muncies use a bolt as illustrated on the right. I use a chisel that I have sharpened to remove the rear seal. reverse sliding, 40) Bearing assy., Use this method on every gasket surface on the transmission. Most of the Muncie four-speed transmissions will have a casting date code on the main case, extension housings, and side cover. Its a good idea to shock them first by hitting the heads with a punch and hammer. Second gear is supporting the geartrain during this mainshaft press procedure. Try to pull the gasket out. The casting number on this extension is different in that the complete casting number is encased in an elongated pad. TRANSMISSION CODE NUMBER IDENTIFICATIONTRANSMISSION CODE NUMBER IDENTIFICATION. Speedometer Muncie manual trans. Use pliers or a spring hook to install the spring. The following six digits were the last six digits of the VIN. The countergear is still dropped to allow it to be placed in this position. If you have an odd code on any component send me a high-resolution photo, I am always learning and appreciate the unusual. Use a 7/16-inch socket and torque the bolt and lock washer to 10 ft-lbs. Muncie casting date codes are very different from other transmission manufacturers. gear bearing I use a pry bar to press the ball down as I put pressure on the lever to move it on top of the ball. - rear, 54) Extension ball, 71) Ball, Reverse assy., Transmission, 55) Bushing, These seals seat in the bore with light taps.
