{"title":"1948-1959 GM SM420 Transmission Parts","description":"\u003cp\u003eShop now for Parts and Manuals for 1948-1959 Chevy and GMC trucks with SM420 Muncie 4 speed transmissions. (SM = Synchro Mesh)\u003c\/p\u003e\n\u003cp\u003eThe Muncie SM420 4 Speed Manual Transmission is a very compact, heavy-duty 4 speed manual transmission that is synchronized in 2nd, 3rd, and 4th gears. The SM420 was used from 1948-1959 as the only 4 speed offered for most 1\/2 ton to 1 ton models, in fact, GM lists the same transmission assembly part number (3917771) to fit 10 through 30 series with 4 speed manual transmissions from 1948-1967!\u003c\/p\u003e\n\u003cp\u003eThe SM420 has a transmission case length that is less than 10-1\/2\". The compact design was made possible by using the same part for mainshaft 1st gear, mainshaft reverse gear, and 1-2 synchro slider. The design is robust enough it was also used on Class 6 Two Ton trucks and it is highly sought after for vintage 4x4 engine and transmission conversions due to its short length and 7.05:1 1st gear ratio. \u003c\/p\u003e","products":[{"product_id":"569-tmc48usb-1948-1953-chevy-and-gmc-truck-factory-service-manual-on-usb","title":"TMC48USB 1948-1953 Chevy and GMC Truck Factory Service Manual on USB","description":"\u003cp\u003e\u003cstrong\u003eTMC48USB 1948-1953 Chevy and GMC Truck Factory Service Manual on USB\u003c\/strong\u003e covers body, chassis, mechanical, and electrical. There are sections on suspension, driveline\/axle, brakes, engine, transmission, body, accessories, etc. This USB includes wiring diagrams. The books are loaded with diagrams and illustrations to show you how to disassemble, repair, and reassemble the various components and frequently gives troubleshooting information. All pages are available to print out as an instant reference while working in the garage, away from the computer. \u003cspan style=\"color: #ff0000\"\u003eIMPORTANT: This Shop Manual does \u003cstrong\u003eNOT\u003c\/strong\u003e cover Major Component Overhaul Procedures!\u003c\/span\u003e\u003c\/p\u003e","brand":"OEM Shop Manual","offers":[{"title":"Default Title","offer_id":41655987339341,"sku":"569","price":44.97,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/Manuals_on_USB_1200__94738.1742236436.1280.1280.jpg?v=1742472368"},{"product_id":"570-tmc54cd-1954-chevy-and-gmc-truck-factory-service-manual-on-cd","title":"TMC54USB 1954 Chevy and GMC Truck Factory Service Manual on USB","description":"\u003cp\u003e\u003cstrong\u003eTMC54USB 1954 Chevy and GMC Truck Factory Service Manual on USB\u003c\/strong\u003e covers body, chassis, mechanical, and electrical. There are sections on suspension, driveline\/axle, brakes, engine, transmission, body, accessories, etc. This USB includes wiring diagrams. The books are loaded with diagrams and illustrations to show you how to disassemble, repair, and reassemble the various components and frequently gives troubleshooting information. All pages are available to print out as an instant reference while working in the garage, away from the computer. \u003cspan style=\"color: #ff0000\"\u003eIMPORTANT: This Shop Manual does \u003cstrong\u003eNOT\u003c\/strong\u003e cover Major Component Overhaul Procedures!\u003c\/span\u003e\u003c\/p\u003e","brand":"OEM Shop Manual","offers":[{"title":"Default Title","offer_id":41655988322381,"sku":"570","price":44.97,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/Manuals_on_USB_1200.jpg?v=1758818834"},{"product_id":"571-tmc55cd-1955-1956-chevy-and-gmc-truck-factory-service-manual-on-cd","title":"TMC55USB 1955-1956 Chevy and GMC Truck Factory Service Manual on USB","description":"\u003cp\u003e\u003cstrong\u003eTMC55USB 1955-1956 Chevy and GMC Truck Factory Service Manual on USB\u003c\/strong\u003e covers body, chassis, mechanical, and electrical. Both the 1955 Truck Manual \u0026amp; 1956 Truck Supplement are included on this USB. There are sections on suspension, driveline\/axle, brakes, engine, transmission, body, accessories, etc. This USB includes wiring diagrams. The books are loaded with diagrams and illustrations to show you how to disassemble, repair, and reassemble the various components and frequently gives troubleshooting information. All pages are available to print out as an instant reference while working in the garage, away from the computer. \u003cspan style=\"color: #ff0000\"\u003eIMPORTANT: This Shop Manual does \u003cstrong\u003eNOT\u003c\/strong\u003e cover Major Component Overhaul Procedures!\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cem\u003eTMC55USB supersedes TMC55CD 1955-1956 Chevy and GMC Truck Factory Service Manual on CD\u003c\/em\u003e\u003c\/p\u003e","brand":"OEM Shop Manual","offers":[{"title":"Default Title","offer_id":41655990353997,"sku":"571","price":44.97,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/Manuals_on_USB_1200.jpg?v=1758818834"},{"product_id":"572-tmc58cd-1958-1959-chevy-and-gmc-truck-factory-service-manual-on-cd","title":"TMC58CD 1958-1959 Chevy and GMC Truck Factory Service Manual on CD","description":"\u003cp\u003e\u003cstrong\u003eTMC58CD 1958-1959 Chevy and GMC \u003c\/strong\u003e\u003cstrong\u003eTruck Factory Service Manual on CD\u003c\/strong\u003e covers body, chassis, mechanical, and electrical. Both the 1958 Truck Manual \u0026amp; 1959 Truck Supplement are included on this CD. There are sections on suspension, driveline\/axle, brakes, engine, transmission, body, accessories, etc. This CD includes wiring diagrams. The books are loaded with diagrams and illustrations to show you how to disassemble, repair, and reassemble the various components and frequently gives troubleshooting information. All pages are available to print out as an instant reference while working in the garage, away from the computer. \u003cspan style=\"color: #ff0000\"\u003eIMPORTANT: This Shop Manual does \u003cstrong\u003eNOT\u003c\/strong\u003e cover Major Component Overhaul Procedures!\u003c\/span\u003e\u003c\/p\u003e","brand":"OEM Shop Manual","offers":[{"title":"Default Title","offer_id":41655990943821,"sku":"572","price":44.97,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/TMC58CD__19495_25437__98837.1707819540.1280.1280.jpg?v=1742472423"},{"product_id":"30336-qu30336-rear-output-seal-for-1948-1967-gm-sm420-transmissions","title":"QU30336 Rear Output Seal for 1948-1967 GM SM420 Transmissions","description":"\u003cp\u003e\u003cstrong\u003eQU30336 Rear Output Seal\u003c\/strong\u003e for 1948-1967 GM SM420 transmissions.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41656913002573,"sku":"30336","price":24.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu30336_1_1200_clean__65175_16789__90301.1707859885.1280.1280.jpg?v=1742508929"},{"product_id":"30337-qu30337-bearing-gasket-and-seal-kit-for-1948-1967-sm420-transmission","title":"QU30337 Bearing, Gasket, and Seal Kit for 1948-1967 SM420 Transmission","description":"\u003cp\u003e\u003cstrong\u003eQU30337 Complete Bearing, Gasket, and Seal Kit\u003c\/strong\u003e for 1948-1967 SM420 Transmissions.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41656913363021,"sku":"30337","price":249.98,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu30337_2922_1600__49078_21416__19730.1707859911.1280.1280.png?v=1742508946"},{"product_id":"30338-qu30338-gasket-set-for-1948-1967-sm420-4-speed-manual-transmissions","title":"QU30338 Gasket Set for 1948-1967 SM420 4 Speed Manual Transmissions","description":"\u003cp\u003e\u003cstrong\u003eQU30338 Gasket Set\u003c\/strong\u003e for 1948-1967 SM420 4 speed manual transmissions.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41656913657933,"sku":"30338","price":19.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu30338_1200_clean__23045_14222__35790.1707859928.1280.1280.jpg?v=1742508964"},{"product_id":"30339-qu30339-small-parts-kit-for-1948-1967-sm420-transmissions","title":"QU30339 Small Parts Kit for 1948-1967 SM420 Transmissions","description":"\u003cp\u003e\u003cstrong\u003eQU30339 Small Parts Kit\u003c\/strong\u003e for 1948-1967 SM420 4 speed manual transmissions.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41656914018381,"sku":"30339","price":74.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu30339_1200_clean__88685_17800__86442.1707859948.1280.1280.jpg?v=1742508987"},{"product_id":"30341-qu30341-shifter-stick-for-cast-iron-top-covers-sm420-sm465","title":"QU30341 Shifter Stick for Cast Iron Top Covers SM420, SM465","description":"\u003cp\u003e\u003cstrong\u003eQU30341 Shifter Stick for Cast Iron Top Covers\u003c\/strong\u003e on 1948-1967 SM420 and 1968-1987 SM465 4 speed manual transmissions.\u003c\/p\u003e \u003cp\u003e\u003cstrong\u003eNeed More Info? \u003c\/strong\u003eUse the handy Links below to access over 40 years of Dan's product and vehicle specific Tech Notes to easily get the information you need for your vehicle's repair, maintenance, or upgrade project!\u003c\/p\u003e \u003cp\u003e\u003cspan style=\"color: #ff0000\"\u003e\u003cstrong\u003eDan the Gear Man® Tech Notes:\u003c\/strong\u003e\u003c\/span\u003e\u003cbr\u003e \u003cstrong\u003e\u003ca href=\"#note1\"\u003eMatching Parts\u003c\/a\u003e \u003c\/strong\u003e\u003c\/p\u003e \u003cp\u003e\u003ca name=\"note1\"\u003e\u003c\/a\u003e\u003cspan style=\"color: #ff0000\"\u003e\u003cstrong\u003eTech Note 1:\u003c\/strong\u003e\u003c\/span\u003e \u003cstrong\u003eMatching Parts\u003c\/strong\u003e\u003cbr\u003e\u003ca href=\"\/products\/52071-qu52071-shift-stick-boot-repair-kit-for-sm420-sm465-np435-transmissions\" target=\"_blank\"\u003eQU52071\u003c\/a\u003e Shift Stick Boot Repair Kit\u003c\/p\u003e \u003cp\u003e\u003cspan style=\"color: #ff0000\"\u003e\u003cstrong\u003eApplications:\u003cbr\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003cstrong\u003eChevy\/GMC:\u003cbr\u003e\u003c\/strong\u003eSM420 4 Speed Manual Transmissions: 1948, 1949, 1950, 1951, 1952, 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1960, 1961, 1962, 1963, 1964, 1965, 1966, 1967\u003cbr\u003eSM465 4 Speed Manual Transmissions: 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41656914149453,"sku":"30341","price":124.98,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu30341_1200_clean__53861_11141__85498.1707859989.1280.1280.jpg?v=1742509020"},{"product_id":"30342-qu30342-3-4-brass-synchro-ring-for-1959-1967-sm420-transmission","title":"QU30342 3-4 Brass Synchro Ring for 1959-1967 SM420 Transmission","description":"\u003cp\u003e\u003cstrong\u003eQU30342 3-4 Brass Synchro Ring\u003c\/strong\u003e for 1959-1967 SM420 4 speed manual transmissions.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41656914247757,"sku":"30342","price":32.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu30342_1200_clean__29667_12384__59083.1707860010.1280.1280.jpg?v=1742509038"},{"product_id":"52067-qu52067-countershaft-front-bearing-for-1962-1967-sm420-transmissions","title":"QU52067 Countershaft Front Bearing for 1962-1967 SM420 Transmissions","description":"\u003cp\u003e\u003cstrong\u003eQU52067 Countershaft Front Bearing\u003c\/strong\u003e for 1962-1967 SM420 4 speed manual transmissions.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41657604112461,"sku":"52067","price":24.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu52067_bottom_1200_clean__84748_13107__43960.1707888798.1280.1280.jpg?v=1742531771"},{"product_id":"52068-qu52068-countershaft-front-bearing-for-1948-1961-sm420-transmissions","title":"QU52068 Countershaft Front Bearing for 1948-1961 SM420 Transmissions","description":"\u003cp\u003e\u003cstrong\u003eQU52068 Countershaft Front Bearing\u003c\/strong\u003e for 1948-1961 SM420 4 speed manual transmissions.\u003c\/p\u003e","brand":"Torque King","offers":[{"title":"Default Title","offer_id":41657604931661,"sku":"52068","price":59.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/QU52068_0310_clean__54597_19453__41169.1707888842.1280.1280.png?v=1742531795"},{"product_id":"52069-qu52069-sm420-mainshaft-pilot-rollers","title":"QU52069 SM420 Mainshaft Pilot Rollers","description":"\u003cp\u003e\u003cstrong\u003eQU52069 SM420 Mainshaft Pilot Rollers\u003c\/strong\u003e. 20 per package.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41657605554253,"sku":"52069","price":19.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu52069_1200_clean__35927_17291__47564.1707888859.1280.1280.jpg?v=1742531812"},{"product_id":"52070-qu52070-rear-output-bearing-for-32-spline-output","title":"QU52070 Rear Output Bearing for 32 Spline Output","description":"\u003cp\u003e\u003cstrong\u003eQU52070 Rear Output Bearing\u003c\/strong\u003e for 32 spline output.\u003c\/p\u003e","brand":"Torque King","offers":[{"title":"Default Title","offer_id":41657605947469,"sku":"52070","price":50.98,"currency_code":"USD","in_stock":true}]},{"product_id":"52071-qu52071-shift-stick-boot-repair-kit-for-sm420-sm465-np435-transmissions","title":"QU52071 Shift Stick Boot Repair Kit for SM420, SM465, NP435 Transmissions","description":"\u003cp\u003e\u003cstrong\u003eQU52071 Shift Stick Boot Repair Kit\u003c\/strong\u003e for SM420, SM465 and NP435 4 speed manual transmissions. Includes: Boot, Retainer, Retention Spring, and Domed Washer.\u003c\/p\u003e \u003cp\u003e\u003cstrong\u003eNeed More Info? \u003c\/strong\u003eUse the handy Links below to access over 40 years of Dan's product and vehicle specific Tech Notes to easily get the information you need for your vehicle's repair, maintenance, or upgrade project!\u003c\/p\u003e \u003cp\u003e\u003cspan style=\"color: #ff0000\"\u003e\u003cstrong\u003eDan the Gear Man® Tech Notes:\u003c\/strong\u003e\u003c\/span\u003e\u003cbr\u003e \u003cstrong\u003e\u003ca href=\"#note1\"\u003eMatching Parts\u003c\/a\u003e \u003c\/strong\u003e\u003c\/p\u003e \u003cp\u003e\u003ca name=\"note1\"\u003e\u003c\/a\u003e\u003cspan style=\"color: #ff0000\"\u003e\u003cstrong\u003eTech Note 1: \u003c\/strong\u003e\u003c\/span\u003e\u003cstrong\u003eMatching Parts\u003c\/strong\u003e\u003cbr\u003e\u003ca href=\"\/products\/30341-qu30341-shifter-stick-for-cast-iron-top-covers-sm420-sm465\" target=\"_blank\"\u003eQU30341\u003c\/a\u003e SM420, SM465 Shifter Stick for Cast Iron Top Covers\u003c\/p\u003e \u003cp\u003e\u003cspan style=\"color: #ff0000\"\u003e\u003cstrong\u003eApplications:\u003cbr\u003e\u003c\/strong\u003e\u003c\/span\u003eSM420, SM465, NP435 4 Speed Manual Transmissions\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41657606144077,"sku":"52071","price":58.98,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu52071_1200_clean__51717_11161__68842.1707888879.1280.1280.jpg?v=1742531839"},{"product_id":"51093-qu51093-40mm-id-deep-groove-type-input-or-np435-output-ball-bearing","title":"QU51093 40mm ID Deep Groove Type Input or NP435 Output Ball Bearing","description":"\u003cp\u003e\u003cstrong\u003eQU51093 Deep Groove Type Input or NP435 Output Ball Bearing\u003c\/strong\u003e was used by Dodge for 1988-1991 transmissions and 1948-1967 SM420 4 Speed Manual Transmission. It is dimensionally interchangeable with \u003ca href=\"\/products\/51112-qu51112-maximum-capacity-ball-bearing\" target=\"_blank\"\u003eQU51112\u003c\/a\u003e. It can handle higher thrust loads due to its deep groove design, but only has 8 balls giving it lower radial capacity. This is a 40mm ID Ball Bearing with Snap Ring for Transmission and Transfer Case applications. Imported.\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41657992872013,"sku":"51093","price":49.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu51093clean__31633_10273__13325.1707898646.1280.1280.jpg?v=1742543290"},{"product_id":"50794-qu50794-import-ball-bearing-np200-np201-np203-np205-transfer-cases","title":"QU50794 Import Ball Bearing  NP200, NP201, NP203, NP205 Transfer Cases","description":"\u003cp\u003e\u003cstrong\u003eQU50794 Import NP205, NP201, NP200 Transfer Case Output and Remote Input Ball Bearing\u003c\/strong\u003e is a quality, imported, name brand Deep Groove Type Radial Ball Bearing\u003c\/p\u003e","brand":"Quad 4x4","offers":[{"title":"Default Title","offer_id":41658517520461,"sku":"50794","price":20.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu50794__56102_10365__11864.1707901206.1280.1280.jpg?v=1742553210"},{"product_id":"51127-qu51127-transmission-input-seal","title":"QU51127 Transmission Input Seal","description":"\u003cp\u003e\u003cstrong\u003eQU51127 Input Seal\u003c\/strong\u003e for 1964-1972 GM 1\/2 Ton to 1 Ton trucks with New Process NP435 and 1948-1967 SM420 Muncie 4 speed manual transmissions.\u003c\/p\u003e","brand":"Torque King","offers":[{"title":"Default Title","offer_id":41658686701645,"sku":"51127","price":17.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu51127_2_1200_clean__98275_17039__18685.1707903928.1280.1280.jpg?v=1742562124"},{"product_id":"51150-qu51150-ball-bearing-for-powertrain-applications","title":"QU51150 Ball Bearing for Powertrain Applications","description":"\u003cp\u003e\u003cstrong\u003eQU51150 Ball Bearing for Powertrain Applications\u003c\/strong\u003e including 1960-1969 GM Rockwell T221 transfer case front output rear bearing and 1947-1967 SM420 4 speed manual transmissions. Includes snap ring. Made in Japan.\u003c\/p\u003e","brand":"Torque King","offers":[{"title":"Default Title","offer_id":41658697613389,"sku":"51150","price":89.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/QU51150_clean__90621_22312__11081.1707904266.1280.1280.jpg?v=1742562729"},{"product_id":"30442-qu30442-sm420-2nd-gear-synchronizer-ring","title":"QU30442 SM420 2nd Gear Synchronizer Ring","description":"\u003cp\u003e\u003cstrong\u003eQU30442 New Old Stock 2nd Gear Synchronizer Ring\u003c\/strong\u003e for 1948-1967 Chevy trucks with Muncie SM420 4 Speed Transmission.\u003c\/p\u003e","brand":"OEM-MFR","offers":[{"title":"Default Title","offer_id":41660898345037,"sku":"30442","price":125.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/files\/qu30442_4_1200_clean__00090_15280__35465.1707955530.1280.1280.jpg?v=1742718348"},{"product_id":"30639-qu30639-sm420-3-4-synchro-assembly","title":"QU30639 SM420 3-4 Synchro Assembly","description":"\u003cp\u003e\u003cstrong\u003eQU30639 Replacement 3-4 Synchronizer Assembly\u003c\/strong\u003e for GM SM420 manual transmissions includes Hub, Slider, Struts, and Springs.\u003c\/p\u003e","brand":"Torque King","offers":[{"title":"Default Title","offer_id":41661337010253,"sku":"30639","price":349.98,"currency_code":"USD","in_stock":false}]}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0603\/0206\/5741\/collections\/sm420_4_speed_with_yoke_output_drawing__99402_46029bdc-0d40-457b-973f-f60cdf148ec4.jpg?v=1773182404","url":"https:\/\/torqueking.com\/collections\/1948-1959-gm-sm420-transmission-parts.oembed","provider":"Torque King 4x4","version":"1.0","type":"link"}