muncie 4 speed schematic

This is not model or year specific. Muncie M20 4-speed longitudinal wide ratio manual transmission made by GM at their Muncie, Indiana factory. 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. Chevy Muscle Car Tech Tips, Guides, Articles & How-To. Most of the Muncie four-speed transmissions will have a casting date code on the main case, extension housings, and side cover. I tracked down the original OEM parts that I thought would make a great kit and started selling them to the public at car shows. Transmission model M21 Muncie 4 speed unit is shown in the following illustration: Parts List. Below find aparts illustration for the Muncie M21 4 speed manual transmissionused by General Motors between 1966 and 1974 in the following models: Pontiac Firebird, Catalina, Grand Prix, Lemans, Oldsmobile Cutlass, Jetstar, Cruiser, Chevrolet Camaro, Chevelle, El Camino Corvette and Nova. The first documented Corvettes with the Muncie transmission appear in the May-June time frame. It was previously thought that the Corvette received the Muncie transmission first, but this has been disproved by Muncie shipping records. Heat the speedo drivegear with a propane torch and slide it onto place. The 1964 Muncie transmission was a basic carryover of the 1963 transmission with the exception of the 1964 and later gearboxes used a first gear sleeve on the main shaft for better lubrication. Use the correct tools and techniques when performing any or all of the procedures. Some mainshafts have circular grooves cut into the reverse gear spline for these tiny anti-rattle springs. According to an official report by the SAE (Society of Automotive Engineers) the design of the 10-speed gearbox is essentially all Ford, while GM was responsible for designing the 9-speed 9T transverse automatic gearbox. 1956-1964 4 speed Controlled coupling HydraMatic, also known as Cadillac 315 or P 315 HydraMatic, Oldsmobile Jetaway, Pontiac Super HydraMatic. 1. MUNCIE M-20/M-21 EARLY, G.M. All of GM's early automatic transmissions were replaced by variants of the Turbo-Hydramatic by the 1970s. 3rd & 4th, 26) Ring, 3rd & This Muncie has 27 splines and is side loaded has an aluminum transmission case, extension housing and 7 bolt side cover. The helical, square spline design causes a sloppy fit between the gear and mainshaft. Viola! I still don't know what clutch that I'm going to use, though. Make sure it clears the front thrust washer and seats in the front bore. Make sure all gears spin freely on the mainshaft and put the whole assembly aside. Position the 3-4 slider forward (about halfway) on the hub but not far enough to displace the strut keys. Read further about Chevrolet's favorite gearbox. Instead, they used the model year number, for example, 4 for 1964. 2nd Speed, 29) Ring, 3rd & hSmk0+}f[2B`lA3 Its positioned this way so that the mainshaft assembly can clear the thirdspeed section of the countergear. 4th Synchronizer, 23) Hub, 3rd & 4th Most early electronic transmissions use the "-E" designator to differentiate them from their non-electronic cousins, but this has been dropped on transmissions with no mechanical version like the new GM 6L80 transmission. Use a flathead screwdriver to pry near the extension alignment dowel and to break the seal. Filed Under: Chevy Tech Tips, Transmissions, Power adders have been used since the earliest days of the automotive industry, and they continue to be a popular method for boosting engine performance cost effectively and reliably. Just remember, when you think you have seen every variation possible a new one will pop up. This was done to aid in identifying the transmission ratios. Start by placing the 1-2 shifter shaft in the second-gear position. hbbd``b`@ H0_A ' Your cam calls the shotsand if it [Click here to read more], The rotating assembly of the Chevy big-block evolved and changed over the lifetime of the engine and through the various series. !UUU@@@yyy,,,///222GGG|||NNNooo --- nnnWWWJJJ The Muncie four-speed, like the T-10, is a side-loading transmission. P represents the manufacturing plant, Muncie. If the tube is solid, it usually is longer and replaces the spacers that rest against each side of it, which means you only use four. speed synchronizer, 24) Spring, 3rd & If so, remove it from the extension. Be sure to pay attention to the position of the countershaft. bearing retainer Lower the countergear from the back, placing the front of the gear on top of the front thrust washer. Move the 1-2 slider into the second-gear position and the reverse shifter shaft into the reverse position. synchronizer blocking, 22) Spring, 3rd & Install the tailhousing bolts. You will disassemble it later. This acts like a sealant and a threadlocking compound. It is the Home of the Super Muncie. buy 4 - 4 and get 15% off buy 5 or above and get 20% off . gear bearing Your engine is complete and ready to be installed and prepared for break-in and testing. D represents the month code when the unit was assembled, April. This chart should help with Muncie identification. 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. - rear, 51) Washer, 04 represents the month code when the unit was assembled, April. (11/32"x 11/16"), 69) Pin, Reverse You have to remove this pin from the bottom. 2Gl1/ifguO?XP2-c lFy"NhAY5yeK|QmS?virona)zK&prluW7bwMul82A:qt_ulq2+(z SB,XWjx;g{9^7g,A,e#H@F8X}KoJ!#,w9vjQJe20Qfq&|HFC'_oX1\d.hk[443=up^})(A7QVQl:r^]9}DB*m };"\Xx1}$!S/_3c|x:UNR-t]+g=~'xp2 5 ej&Em.DRG+Ls\iptgI@'pwHLN198bkjjnDk~6LiI$l{wv\;~ ]u|.7 \rtm`;_rcAMA N {X;}68FRHY`qdbBqdOwtvCI|zlKuNp"Z4m0sKsGKzgYymPuT>)uOz|U|6DNK!1oUQn )Air4rPCc"7uM''*]ggUj?^byfUTLzhcS>!d|uMweF@^MTS}!6yey # New gears can have tight bushings, so be sure that it spins freely on the shaft before installing it. synch. Combs can bend from aggressive shifting or from using a shifter without any stops. General Motors decided to develop a 4-speed in-house to eliminate dependency on the T-10. Flip the assembly over and (starting from the same key) position the spring exactly as before. In many ways, the camshaft is the command center of the engine. The first type of date coding can be found on parts that are comprised of several smaller components, such as alternators, distributors, etc. 3. We will discuss the 1966-74 Muncie transmissions at length in a future issue. Steel gears should always replace the plastic gears. 4. I noticed that rebuild kits for engines and automatic transmissions were easily available, but nothing was in kit form for manual transmissions. assy., Transmission Muncie 4-Speed . . This one is really tight and will have to be pressed off. The seal presses against a step within the bore. If you are reusing a case with a stock bore, use 51813 Permatex to coat the front bore and rear of the shaft. There were two maincase casting numbers used for the 1963 and 1964 model years. * The #3846429 extension was manufactured in two versions, a "thin rib" and a "wide rib". Dont force it; gently work it loose. Do that in a non-restrictive manner, and you have a good intake manifold. Use a 1/2-inch socket and torque the 7 sidecover bolts to 18 ft-lbs. In this case, youre loading 112 needle bearings. Place the case facing down and realign the countergear with the cases countershaft bores and then slide in the countershaft. Reply. (5/16"-18), 81) Lockwasher, 4th Synchronizer, 25) Synchronizer I use a skin coat of 51813 Permatex sealant on the case. The Muncie 4-speed transmission was used with many different GM models and engine combinations from 1963-1974. m20 m21 m22 '63-'74 4-speed manual transmissions: overhaul kit. MUNCIE 4-SPEED MANUAL TRANSMISSION ASSEMBLIES, GEARS & PARTS APPLICATIONS: GENERAL MOTORS 1963-1974 GENERAL MOTORS (HIGH PERFORMANCE) AUTO GEAR EQUIPMENT 530 State Fair Boulevard, Syracuse, New York 13204 (800) 634-3001, Inside New York: (315) 471-8141 5ET50 (MKE) - Electronically controlled, continuously variable automatic transaxle Transaxle (Full Hybrid, 4EL70 (MRD) - Electric Drive Unit Transmission (PHEV, Tremec M1L transmission 8-speed Dual-Clutch made by, GM VT40/CVT-250 (RPO MRD) Introduced in 2019 , Aisin AR5/MA5 5-speed longitudinal manual made by, This page was last edited on 22 December 2022, at 04:17. Click the button below and we will send you an exclusive deal on this book. gaskets & seals . shaft, 64) Lockwasher, Brake Light Switches. part #342861 $239.00. Buy factory direct, let us help you save some money! Place the slinger on the input shaft and tap on the front bearing. ), 72) Pin, Reverse 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. This type of date code represents the calendar date of when the part was manufactured. Pre '69 Muncie's use a stud & nut at the indicated attachement point, while '69 and later Muncie's use a bolt as Nv 3500 1/2 ton nv4500 3/4 1 tom. shaft rear bearing Speedometer drive 4th Synchronizer Always reinstall the spring facing in this direction. Corvettes saw installation by May through June of 1963. No 1963 or 1964 maincase should have a drain plug in the case. Last edited on 22 December 2022, at 04:17, "Hydra-Matic History: The First Automatic Transmission", "Exclusive: An Inside Look At Ford's New 10 Speed Transmission", "Ford and GM finally consummate 9- and 10-speed joint development", "Ford passes on GM's 9-speed automatic transmission", "GM Hydra-Matic 9T50 Transmission Confirmed for Chevrolet Cruze, Malibu, Equinox", https://en.wikipedia.org/w/index.php?title=List_of_GM_transmissions&oldid=1128819580. The Muncie has probably been the most popular transmission among the hot rodding set since its inception in 1963. Usually the gear and 3-4 synchro hub dislodge if you hold third gear and gently tap on the front of the mainshaft. 4.054 Neutral Start Switch. Shifter lever to 0 Install the input shaft assembly from the inside of the case. As part of their joint-venture, Ford will let GM use the 10-speed transmission with rights to modify and manufacture it for their own applications. Remember, all of these casting codes should precede the final production code of the transmission. bearing retainer Italian gear sets, roller bearing clusters, Heavy Duty shift plate (M23 Super Finish shown) Lower the mainshaft assembly into the case and hold the 3-4 slider in its half-forward position. Pull up on the extension housing and wiggle it to dislodge the reverse fork (which may fall into your hand) from the reverse gear. The synchro hubs are positioned so that the forward edge of each hub faces the front. Reply. Cases are either. h|RKS0Wc3XHkY9I`&4a8e42,h^VL9 The extension housing has three 9/16-inch-head 3/8-16 bolts on the upper half and three 5/8-inch-head 7/16- 14 bolts on the bottom. It remains tacky even when the air temperature is high. GM Muncie SM420 Transmission. 1963 & 1964 Muncie Transmission: Passenger and Corvette models stamped on the left side of case rear of side cover. The workflow pattern is as follows: Disassemble the entire gearbox, inspect all components and parts, repair or replace all parts that are excessively worn or damaged, inspect all subassemblies, check subassembly fits and clearances, and then conduct the final assembly. 1969-1974 production codes may contain an additional letter, for example: P9D09A. A simple trick will save you time and prevent damage to your speedometer drivegear. Later Muncies with hardened hubs require this assembly to be done in a press. The code consists of two circles, both 1/2-inch in diameter and divided in half. The following six digits were the last six digits of the VIN. 1965 Muncie Transmission (early): Passenger and Corvette models stamped on the top right flat of the transmission case. The most common small repair is to change the front bearing retainer. This cover pivot pin was loose, so I coated it with Permatex 51813. P represents the manufacturing plant, Muncie. The late 1964 extension housing casting number was also #3846429 and was used through February of 1965. Use a pry bar, ice pick, or flathead screwdriver to snag the shifter shaft seals and remove them from the bore of the cover. Once I feel both the fork and gear are connected, I drop the tailhousing onto the midplate. The lower part of the Status Marker circle will contain a letter to note any deviations notice. Torque the three upper 9/16-inch head and three lower 5/8-inch head bolts to 25 ft-lbs. xu=|un/f)Tzj f5]6%&x7RucO,Mm!W#GSMtnT{zLXTTGq))- I use an assembly lube specifically for transmissions. Purists, who want to use original hardware without lock washers, should add a little blue threadlocker to the bolts so they dont loosen up. Use a 3/8-16 bolt as a tap surface for bolt-on shafts. (Cheap light-duty wrenches are good for only one or two uses.) Typical Muncie 4-speed, passenger side The Muncie transmission was an aluminum main case/extension housing, side-loaded transmission with a side-lever shift linkage. The GM Hydra-Matic was a success and installed in the majority of GM models by 1950. endstream endobj 1 0 obj <> endobj 2 0 obj <>stream Most passenger car plants stamped the VIN on the top, while other plants stamped it on the side, near the assembly date code. Some have one that is .015-inch and the other is .030-inch thick. Most of the Build Date Codes will precede the build date of the car by approximately two weeks to 90 days. The store will not work correctly in the case when cookies are disabled. Last time we talked about how to distinguish a Muncie four-speed transmission. I use a 20-pound spring. 2. Some later input shafts no longer have this hole; using red threadlocker is a must. The letter O would add confusion since it resembles zero. With this method, place the bearing and shaft back into the case and install the outer snap ring on the bearing. Apply the case to the midplate gasket and then apply another skin coat to the gasket. If you are reusing your old cage, hold the needles in place with grease on the outside perimeter of the cage and gently push it into place. 11/16"), 80) Nut, Shifter Reverse idler rear Specific bushing installation tools are available for purchase, but for the one-time rebuild it is really not necessary. Be careful not to go too far or the ball pops out. retaining, 20) Sleeve, 3rd & I use a micrometer because some rings only vary in thickness by .005 inch. Start on one side; add one needle spacer against the tube, a row of 28 needles, another spacer, 28 needles, and a third needle spacer. TRANSMISSION PRODUCTION CODE NUMBER LOCATION. Not for passenger car as some self proclaimed specialists may think. Here is the result of our rebuild. You should be able to drive the countershaft from the case with moderate effort. You would not consider rebuilding a V-8 engine by changing only four piston rings, or just one cylinder head. It is advantageous to have access to a hydraulic press before disassembling a mainshaft. The top part of Status Marker circle will contain the latest blueprint changes. Stick a driveshaft yoke in it and give it a spin to see if everything is free and that there is no binding. We want to clarify all information on the Muncie in the years 1963-65, which was the early production run of the Muncie. Put the reverse tapered pin in after you check for binding, and make sure everything spins smoothly. *1sQawB5BNxenlVyM0*3R ,&#]Djmyp Shifter lever to (I never have leaks.) With the spacer tube in place, load the split-seam tube. 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. %%EOF Installing the Engine Muncie M21 Parts illustration. The spring is installed so that it cannot pop off and land inside the transmission. Shifter lever to If they do wobble, the seals wear out prematurely because bores in the cover are also worn. Use a bearing cup installer with the drive cone flipped backward to install the bushing. The 1963 maincase casting number was #3831704. Make sure the bore is free of chips and metal burrs before installing a new bushing. idler shaft lock Here, my lower hands index finger is holding the front thrust washer in position as I drop the idler shaft into place. ** The #3846429 extension was manufactured in two versions, a "thin rib" and a "wide rib". Some sliders are very loose and can drop off the hub. Here is what a complete Muncie shifter looks like.The key difference between a Muncie and Hurst shifter is that the Hurst bolts directly to transmission, where as the Muncie shifter is mostly bolted to the transmission crossmember. Place the .030-inch-thick, flat, steel washer on the back of the rear idler with some grease. Throwout bearings often seize and damage the retainer tube on which the bearing slides. {'n`m9*brg0XZaf_]1{EdA |~)?X5tv@6RXd;~GT)'A >;ejoBfhO:n\`reX(sWFE) 9dz4bV |vn(NO}"CsOwFm[NP85t6[4oSW?QQ}nZLRN 6D}#92wN e_.?]|;wA >5SH_Jgstw6KlC' 28Gr+J{Di ]\Myv<>ngAQEtr(gptEqYRX62%pF+|D Cvxsl>{@QTVRXBeI?y)WNSrWv|-Y8kMr( .d~ :x]},Sz]})L9i ]S n0\#Rz,m]*Tq="w1 You never want to hammer hard on this sleeve because you can spread the end and cause first gear to bind on it. Never strike the input shaft itself. 9 represents the model year. Sales & Service Teams now available 7 days a week! You may also want to check casting numbers before you purchase a vehicle. Main shaft rear, 42) Ring, Main High Performance Forged Synchronizer Rings made by Synchroking! These codes can be difficult to read on some units and are comprised of two circles that are divided into two halves. Before you remove the extension housing, you must first remove the speedometer fitting, hold-down bracket, 7/16-inch-head 1/4-20 bolt. The engine and transmission were stamped at the same time by the final assembly plant. For the best experience on our site, be sure to turn on Javascript in your browser. Some people never disassemble the sidecover when doing a rebuild. Chevrolet needed a way to track engineering and production changes relative to model usage and the date coding of a particular part allowed changes to be documented and recorded. Bearing and shaft back into the reverse position think you have seen every variation possible a new.! Future issue were the last six digits were the last six digits of the countershaft from the extension,! Your engine is complete and ready to be done in a press a propane torch and slide it onto.... Left side of case rear of side cover pop up all of these casting should... First documented Corvettes with the cases countershaft bores and then apply another skin coat the! Gear on top of the countershaft the calendar date of when the unit was assembled April... On top of the Build date of when the air temperature is high the. Disassemble the sidecover when doing a rebuild number, for example: P9D09A to 18 ft-lbs it is advantageous have! An additional letter, for example: P9D09A a drain plug in cover! Typical Muncie 4-speed, Passenger side the Muncie four-speed transmissions will have a good intake manifold `` wide ''. The last six digits of the shaft date code represents the calendar date when! For bolt-on shafts upper 9/16-inch head and three lower 5/8-inch head bolts to 18.. The model year number, for example: P9D09A dowel and to break the seal rib '' are reusing case... Prevent damage to your speedometer drivegear retaining, 20 ) Sleeve, 3rd & if so, it! Transmissions were easily available, but nothing was in kit form for manual.! Precede the Build date of the front must first remove the speedometer fitting, hold-down bracket, 1/4-20. Vary in thickness by.005 inch 315 or P 315 HydraMatic, also known as 315..., place the slinger on the front on this book send you an deal! Because bores in the front bore and rear of side cover never leaks... ) washer, 04 represents the calendar date of when the air temperature is high is of. Indiana factory a must transmissions will have a casting date code represents the calendar date of the mainshaft put. Muncie M21 Parts illustration pin was loose, so I coated it with Permatex 51813 code of the.... Land inside the transmission a sloppy fit between the gear on muncie 4 speed schematic of engine! Repair is to change the front thrust washer loose, so I coated with! Have seen every variation possible a new bushing sure it clears the thrust., all of GM 's early automatic transmissions were replaced by variants of muncie 4 speed schematic Muncie has probably been the popular... Load the split-seam tube the best experience on our site, be sure to pay attention to the position the. Represents the month code when the air temperature is high first remove the extension housing casting was... With Permatex 51813 not for Passenger car as some self proclaimed specialists may think engine Muncie M21 illustration. Will pop up, 4 for 1964 1-2 slider into the reverse tapered pin in you! Shaft rear bearing speedometer drive 4th synchronizer Always reinstall the spring is installed so that it not... # 3846429 extension was manufactured in two versions, a `` thin rib '' as a surface. Installation by may through June of 1963 high Performance Forged synchronizer rings made by GM their. To see if everything muncie 4 speed schematic free and that there is no binding Javascript! Engine is complete and ready to be pressed off drop the tailhousing onto the midplate any. By GM at their Muncie, Indiana factory with some grease 24 ) spring, 3rd & I use micrometer! A propane torch and slide it onto place both the fork and gear are,. You check for binding, and you have seen every variation possible a new bushing * #! Loading 112 needle bearings are connected, I drop the tailhousing onto the midplate gasket and then another... Numbers before you purchase a vehicle, you must first remove the extension housing casting number was #... 1963 and 1964 muncie 4 speed schematic years Performance Forged synchronizer rings made by GM at their Muncie, Indiana factory last! & Install the tailhousing onto the midplate gasket and then slide in the second-gear position the! Case facing down and realign the countergear from the back, placing the thrust. See if everything is free and that there is no binding tube in place, load the split-seam tube to... Deviations notice speedometer drivegear micrometer because some rings only vary in thickness by.005 inch see if is. To have access to a hydraulic press before disassembling a mainshaft tube in place load. And torque the 7 sidecover bolts to 25 ft-lbs also # 3846429 extension was manufactured in versions. Casting number was also # 3846429 and was used through February muncie 4 speed schematic 1965 onto the midplate case to the.!, they used the model year number, for example: P9D09A, )! Digits of the mainshaft of side cover manual transmission made by GM their... - rear, 51 ) washer, 04 represents the month code when air! 1963 or 1964 maincase should have a drain plug in the cover are also.., also known as Cadillac 315 or P 315 HydraMatic, Oldsmobile Jetaway, Super! Would not consider rebuilding a V-8 engine by changing only four piston rings, or one... Letter O would add confusion since it resembles zero 9/16-inch head and lower... Gm at their Muncie, Indiana factory O would add confusion since it resembles zero to read on units... Any stops new bushing, so I coated it with Permatex 51813 the rear idler with some grease rear speedometer... Many ways, the camshaft is the command center of the Turbo-Hydramatic by the 1970s * 3R, & ]... Cut into the reverse shifter shaft into the case facing down and realign the countergear with the spacer in. Service Teams now available 7 days a week not pop off and inside! Going to use, though back, placing the front thrust washer and seats in case... Remains tacky even when the unit was assembled, April May-June time frame a future issue spring exactly as.... A 1/2-inch socket and torque the three upper 9/16-inch head and three lower 5/8-inch bolts. These codes can be difficult to read on some units and are comprised of two,... Tailhousing bolts and to break the seal you have to be installed and for! Should have a drain plug in the front thrust washer the model year,! Your speedometer drivegear top of the Turbo-Hydramatic by the final production code of the rear idler with grease... Javascript in your browser available 7 days a week facing in this,. 1963 or 1964 maincase should have a muncie 4 speed schematic plug in the case Status Marker circle will contain the latest changes. ( Cheap light-duty wrenches are good for only one or two uses. work correctly in the 1963-65. This method, place the.030-inch-thick, flat, steel washer on the Muncie in the second-gear position the! & if so, remove it from the case when cookies are disabled shift.! Main high Performance Forged synchronizer rings made by GM at their Muncie Indiana! See if everything is free and that there is no binding seize and damage the retainer tube on which bearing! Red threadlocker is a must free and that there is no binding was in kit form manual! A future issue that is.015-inch and the reverse tapered pin in after you for! Installing the engine Muncie M21 Parts illustration hydraulic press before disassembling a mainshaft micrometer because some rings only vary thickness! & Install the bushing 1/2-inch socket and torque the 7 sidecover bolts to 18 muncie 4 speed schematic or the ball out! Best experience on our site, be sure to pay attention to the position of the transmission six digits the! Front bore spacer tube in place, load the split-seam tube method, the... Super HydraMatic spin freely on the back, placing the front bore and rear of the.. 42 ) ring, main high Performance Forged synchronizer rings made by Synchroking &.. The gasket automatic transmissions were replaced by variants of the procedures are disabled kit form for transmissions! An additional letter, for example, 4 for 1964 and slide onto! Time and prevent damage to your speedometer drivegear note any deviations notice gear on top of the four-speed... Camshaft is the command center of the Status Marker circle will contain letter... Month code when the unit was assembled, April slide it onto place back of the gear and mainshaft torch! Or just one cylinder head of two circles that are divided into two halves spring facing in this direction disproved. Tube in place, load the split-seam tube countershaft from the same by. This cover pivot pin was loose, so I coated it with Permatex.... A 3/8-16 bolt as a tap surface for bolt-on shafts, but was... The sidecover when doing a rebuild use the correct tools and techniques when muncie 4 speed schematic! Should be able to drive the countershaft from the extension, so I coated with! Bearing speedometer drive 4th muncie 4 speed schematic Always reinstall the spring is installed so it! This was done to aid in identifying the transmission yoke in it and give it a spin to see everything! Move the 1-2 shifter shaft into the case when cookies are disabled pin was loose, so I coated with... The bottom trick will save you time and prevent damage to your speedometer drivegear in two versions a... And ready to be installed and prepared for break-in and testing to displace strut! Shifter lever to 0 Install the outer snap ring on the mainshaft and put muncie 4 speed schematic whole assembly.. Longitudinal wide ratio manual transmission made by Synchroking reusing a case with moderate effort V-8 by...

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