These quality SM420 manual transmission parts, rebuild kits and overhaul kits are designed to be top of the line overhaul kits. We have include information on how to identify individual transmissions, application information, model year, detailed kit and part availability by transmission type. Borg Warner transmissions are covered in this section SM420's, rear wheel drive (RWD), requiring 4 speed applications.
These quality SM420 manual transmission parts, rebuild kits and overhaul kits are designed to be top of the line overhaul kits. We have include information on how to identify individual transmissions, application information, model year, detailed kit and part availablity by transmission type. Borg Warner transmissions are covered in this section SM420's, rear wheel drive (RWD), This transmission was used by General Motors in Chevrolet and GMC Pickup trucks from 1954 to 1967 requiring 4 speed applications.

Different overhaul kits are available depending on the extent of the overhaul that you plan, the contents of the kits are described as follows:

  • DTS BKXXX Kits (RWD): Main case bearings, gaskets and seals. Syncro rings if required are sold separately in sets.

    Information and parts are provide for the following Transmission: Muncie SM420 4 Speed (RWD)

IDENTIFICATION - SM420 4spd, RWD or 4WD Top loaded, tower shift "granny-low" transmission found in light and heavy duty applications. Cast iron case with cast iron top cover. Non-synchronized 1st, but has only brass type synchro rings for 3rd/4th. All gears on the countershaft are removeable except for 1st. Early units have threads on the input shaft and do not have a front seal. The case has one P.T.O opening.

It's easy to get the correct parts the first time from drivetrain.com.  Using the application tables below just locate your vehicle model, model year,  number of cylinders and engine size read across to identify correct overhaul kit part number.  Make a note of the part number and complete our secure easy order form.
 
Below you will find parts for the SM420 4 speed transmission used in Chevrolet and GMC.   In addition to these overhaul kits we can provide miscellaneous hardparts, don't see what you need just give us a call.

CHEVROLET
  Model Cyl. Engine Year Description Overhaul Kit
  PICKUP and VAN 6cyl 261 ci 1954-61 Iron case and iron top cover DTSBK108
  PICKUP and VAN 8cyl 288ci 1955-59 Iron case and iron top cover DTSBK108
  PICKUP and VAN 8cyl 316ci 1955-59 Iron case and iron top cover DTSBK108
  PICKUP and VAN 8cyl 336ci 1955-59 Iron case and iron top cover DTSBK108
  PICKUP and VAN 8cyl 347ci 1955-59 Iron case and iron top cover DTSBK108
  PICKUP and VAN 6cyl 305ci 1960-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN 6cyl 351 ci 1960-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN 6cyl 194ci 1963-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN 6cyl 230ci 1963-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN 6cyl 250ci 1963-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN 8cyl 283ci 1963-67 Iron case, iron top cover DTSBK108
  STEPVAN (Forward Control) 6cyl 194ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 6cyl 230ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 6cyl 292ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 8 cyl 283ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 8 cyl 350ci 1967 Iron case, iron top cover - case has one PTO cover DTSBK108
GMC  
  PICKUP and VAN FULL SIZE 6cyl 261 ci 1954-61 Iron case, iron top cover DTSBK108
  PICKUP and VAN FULL SIZE 6cyl 235ci 1954-62 Iron case, iron top cover DTSBK108
  PICKUP and VAN FULL SIZE 8cyl 288ci 1955-59 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN FULL SIZE 8cyl 316ci 1955-59 Iron case, iron top cover DTSBK108
  PICKUP and VAN FULL SIZE 8cyl 336ci 1955-59 Iron case, iron top cover DTSBK108
  PICKUP and VAN FULL SIZE 8cyl 347ci 1955-59 Iron case, iron top cover DTSBK108
  PICKUP and VAN FULL SIZE 6cyl 305ci 1960-67 Iron case, iron top cover DTSBK108
  PICKUP and VAN FULL SIZE 6cyl 351 ci 1960-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN FULL SIZE 6 cyl 194ci 1963-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN FULL SIZE 6 cyl 230ci 1963-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN FULL SIZE 6cyl 250ci 1963-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  PICKUP and VAN FULL SIZE 8cyl 283ci 1963-67 Iron case, iron top cover DTSBK108
  STEPVAN (Forward Control) 6 cyl 194ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 6 cyl 230ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 6 cyl 250ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 6 cyl 292ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 8 cyl 283ci 1965-67 Iron case, iron top cover - case has one PTO cover DTSBK108
  STEPVAN (Forward Control) 8 cyl 350ci 1967 Iron case, iron top cover - case has one PTO cover DTSBK108

Part Number

Description

Type

Years

Syyncro Ring Kit
ASK135 Sychro Ring Kit For Units with front seal

1959-67

Miscellaneous Kit
301419 Small Parts Kit

1948-67

DLG-SM420G+K Gasket and Seal Kit

1948-67

Bearing Retainer
ALT3761932 Front Bearing Retainer (Casting # 3761932) with 9 1/4" Maindrive

1959-67