Transmission Rebuild - Manual

Complete removal, disassembly, inspection, rebuild, and reinstallation of the Borg-Warner T56 6-speed manual transmission in the 1992 Dodge Viper, including clutch inspection and driveline component service.

Warnings

Tools required

Parts

• T56 transmission overhaul kit (synchros, bearings, seals, gaskets) × 1 — Tremec T56 rebuild kit for 1992 Viper application
• Input shaft seal × 1 — Included in overhaul kit or order separately
• Tailshaft seal × 1 — Included in overhaul kit
• Shift tower gasket × 1 — Use OEM specification
• Clutch release bearing × 1 — Verify condition, replace if worn
• Transmission drain plug washer × 1 — Use new copper or aluminum washer
• Flywheel bolts × 6 — New bolts required if TTY type
• Transmission mounting bolts × 1 — Inspect and replace if damaged
• Driveshaft U-joint grease × 1 — High-temp chassis grease
• Thread locker (medium strength) × 1 — Loctite 243 or equivalent

Fluids

• Mopar MS-9224 or 75W-90 GL-4 manual transmission fluid — 4.5 qt

Preparation

1. Park vehicle on level ground and engage parking brake. Place wheel chocks behind rear wheels.
2. Disconnect negative battery cable to prevent electrical issues during removal.
3. Raise vehicle on a lift or jack stands to provide adequate working clearance underneath. Ensure vehicle is fully supported and stable.
4. Remove exhaust system from manifolds back to provide clearance for transmission removal. The exhaust routing on the Viper requires complete removal for transmission access.
5. Mark driveshaft orientation to transmission and rear differential flanges using paint or punch marks to ensure proper phasing on reinstallation.
6. Drain transmission fluid into appropriate container by removing drain plug from transmission case. Dispose of fluid properly.
7. Prepare clean workspace with parts trays, labels, and cleaning supplies for transmission disassembly. Organization is critical for successful rebuild.

Procedure

1. 1

   Remove driveshaft assembly
   Remove the 4 bolts securing driveshaft front flange to transmission output flange. Remove the 4 bolts securing driveshaft rear flange to differential input flange. Support driveshaft and carefully slide it out from transmission tailshaft. Inspect U-joints for wear and replace if excessive play is present. Store driveshaft in a safe location where it will not be bent or damaged.
2. 2

   Disconnect hydraulic clutch line and shifter linkage
   Locate hydraulic clutch line connection at bellhousing. Remove retaining clip and disconnect quick-disconnect hydraulic line from slave cylinder. Cap or plug line to prevent fluid loss. Remove shift tower mounting bolts (typically 4 bolts) and lift shift tower assembly away from transmission. The shift tower includes the shifter mechanism and boot assembly on the Viper.
3. 3

   Disconnect electrical connectors
   Disconnect reverse light switch connector on driver side of transmission case. Disconnect the speedometer output (verify whether the 1992 Viper uses an electronic vehicle speed sensor connector or a mechanical speedometer cable) on the transmission case. Secure wiring harnesses away from transmission removal path using zip ties or tape.
4. 4

   Support engine and transmission
   Position floor jack with wood block under engine oil pan to support engine weight. Position transmission jack under transmission with adapter plate to distribute load across transmission case. Raise transmission jack until it just contacts transmission and takes slight load, but do not lift vehicle.
5. 5

   Remove transmission mount and crossmember
   Remove the 2 nuts securing transmission mount to crossmember. Remove the 4 bolts securing crossmember to frame rails. Carefully lower and remove crossmember assembly. Inspect transmission mount rubber for deterioration and replace if cracked or oil-soaked.
6. 6

   Remove bellhousing-to-engine mounting bolts
   Working from underneath and through the side access points, remove all bellhousing-to-engine block mounting bolts. There are 6 mounting bolts securing the bellhousing to the engine block on the Viper V10. Support transmission firmly on transmission jack as you remove final bolts.
7. 7

   Separate transmission from engine
   With assistant's help, carefully slide transmission rearward on transmission jack, ensuring input shaft clears clutch disc and pilot bearing. The transmission is heavy and awkward - move slowly and keep weight balanced on jack. Once input shaft is clear of bellhousing (approximately 6 inches), lower transmission on jack and roll away from vehicle. Do not allow transmission to hang on input shaft or clutch components.
8. 8

   Inspect and service clutch assembly
   With transmission removed, inspect clutch disc for wear, oil contamination, or glazing. Check pressure plate for hot spots, cracks, or warped fingers. Measure flywheel runout with dial indicator (should be within 0.005 inch). If replacing clutch, use clutch alignment tool to center new disc on flywheel before installing pressure plate. If reusing clutch, mark pressure plate orientation to flywheel. Remove flywheel mounting bolts in a criss-cross (star) pattern if flywheel resurfacing is required. Verify flywheel bolt torque specification and whether bolts are torque-to-yield (single-use) against factory documentation.
9. 9

   Mount transmission on rebuild stand and drain remaining fluid
   Secure transmission to appropriate rebuild stand or sturdy workbench with case horizontal. Remove fill plug from side of case. Invert transmission if necessary to drain any remaining fluid from all internal cavities. Clean exterior of transmission case thoroughly with degreaser and brush before disassembly to prevent contamination of internal components.
10. 10

    Remove external components
    Remove clutch release bearing and fork from bellhousing. Remove vehicle speed sensor from case. Remove reverse light switch. Remove shift tower mounting surface and gasket. Remove tailshaft housing bolts (typically 6-8 bolts around perimeter) and carefully slide tailshaft housing off output shaft while catching loose thrust washers or shims. Note position of any shims for reassembly.
11. 11

    Disassemble transmission case
    Remove bellhousing-to-case bolts (count and note locations as bolt lengths may vary). Carefully separate bellhousing from main case, watching for dowel pins that may fall. Remove rear case extension housing if equipped. Split main case halves by removing case bolts in sequence (typically 16-20 bolts around perimeter). Use plastic mallet to gently tap case halves apart - do not pry between sealing surfaces. Lift top case half straight up to expose gear train assembly.
12. 12

    Document gear stack configuration and measure clearances
    Before disturbing any components, photograph gear positions and shim locations. Measure input shaft endplay using dial indicator and feeler gauges. Measure output shaft endplay. Record all measurements for comparison during reassembly. Note position of all snap rings, thrust washers, and shims. The T56 uses specific shimming for proper gear mesh and bearing preload - documentation is essential.
13. 13

    Remove gear assemblies and shafts
    Remove counter shaft assembly (cluster gear) by removing retaining snap ring and carefully lifting shaft out of case. Remove reverse idler gear and shaft. Remove input shaft assembly from front bearing. Remove output shaft assembly from rear bearing. Keep all gears, synchronizers, and spacers in order on each shaft for inspection and reassembly. Place components on clean bench in disassembly order.
14. 14

    Disassemble synchronizer assemblies
    Working on one synchronizer at a time, mark hub-to-sleeve orientation with punch marks. Remove snap rings retaining synchronizer assemblies to output shaft. Carefully slide synchronizer sleeves off hubs while noting position of shift fork engagement grooves. Keep springs, keys, and blocking rings together with their respective assemblies. Inspect all synchronizer cones for wear grooves or scoring. Measure blocking ring-to-gear cone clearance - typical specification is 0.020-0.040 inch minimum.
15. 15

    Remove and inspect bearings
    Using appropriate bearing pullers, remove input shaft bearing, output shaft bearings, and counter shaft bearings. Inspect bearing races in case halves for pitting, spalling, or discoloration indicating overheating. Remove bearing races from case using race puller or driver from backside. Clean all bearing bores thoroughly. Inspect all gear teeth for chips, cracks, or excessive wear. Measure gear backlash between mating gears and compare to specifications.
16. 16

    Clean and inspect all components
    Clean all parts in solvent and dry with compressed air. Inspect all gear teeth under magnification for cracks or stress marks. Check all shaft splines for wear or damage. Inspect shift forks for wear grooves or cracks. Measure fork pad thickness and compare to specifications. Check case halves for cracks, stripped threads, or damaged bearing bores. Inspect shift rail bores for excessive wear. Replace any components that do not meet service specifications.
17. 17

    Install new bearings and races
    Install new bearing races into case halves using appropriate drivers, ensuring races are fully seated and square in bores. Coat bearing races lightly with assembly lube. Press new bearings onto shafts using press and appropriately sized drivers that contact bearing inner race only. Do not press on balls or outer race. Verify bearings rotate smoothly without binding after installation.
18. 18

    Reassemble synchronizer assemblies
    Install new synchronizer blocking rings and keys per overhaul kit instructions. Align hub-to-sleeve orientation marks and slide sleeves onto hubs, ensuring springs and keys are properly positioned in detent slots. Blocking rings should have specified clearance to gear cones. Install synchronizers onto output shaft in correct positions, securing with new snap rings. Verify snap rings are fully seated in grooves.
19. 19

    Reassemble gear train in case
    Install output shaft assembly with gears and synchronizers into lower case half, ensuring bearing is seated in case bore. Install counter shaft (cluster gear) assembly with thrust washers in correct positions. Install reverse idler gear and shaft. Install input shaft assembly into front bearing bore. Position all shims and thrust washers as documented during disassembly. Apply light coating of assembly lube to all gear teeth and bearing surfaces.
20. 20

    Verify gear clearances and install upper case
    Rotate shafts to verify smooth operation and proper gear mesh before installing upper case. Measure endplay on input and output shafts to confirm proper shimming. Apply thin bead of RTV sealant to case mating surface per factory specifications. Carefully position upper case half, aligning dowel pins. Install case bolts finger-tight, then torque in criss-cross pattern working from center outward to avoid distortion. Rotate shafts after case assembly to verify no binding occurs.
21. 21

    Install external housings and components
    Install tailshaft housing with new gasket or RTV sealant as specified. Install new tailshaft seal using seal driver. Install bellhousing with new gasket or sealant. Install shift tower mounting surface with new gasket. Install vehicle speed sensor and reverse light switch with new O-rings. Apply thread locker to sensor mounting bolts. Install new input shaft seal in bellhousing using seal driver.
22. 22

    Install clutch release components
    Install new or inspected clutch release bearing onto input shaft bearing retainer. Install clutch fork into bellhousing pivot, ensuring fork engages release bearing properly. Apply high-temp grease to fork pivot ball and bearing contact surfaces. Verify fork moves smoothly through full travel range.
23. 23

    Prepare transmission for installation
    Fill transmission with the factory-specified capacity (approximately 4.5 quarts — verify exact capacity) of Mopar MS-9224 or 75W-90 GL-4 manual transmission fluid through fill hole. Install fill plug with new washer. Rotate input shaft several times to distribute fluid through bearings and gears. Check for leaks around all seals and gaskets. Apply thin coat of high-temp grease to input shaft splines to ease clutch disc engagement during installation.
    ℹ️Do not use GL-5 gear oil in this transmission as it may damage brass synchronizers. Only use GL-4 rated fluid or Mopar MS-9224.
24. 24

    Install transmission to engine
    With assistant's help, position transmission on transmission jack and raise into position behind engine. Ensure transmission is level and aligned with engine block. Carefully guide input shaft through clutch disc splines and into pilot bearing, rotating transmission slightly if needed to align splines. Push transmission forward until bellhousing mates flush with engine block. Start all 6 bellhousing-to-engine mounting bolts by hand before tightening any. Torque mounting bolts in star pattern.
25. 25

    Install crossmember and transmission mount
    Raise transmission jack to align transmission mount with crossmember location. Position crossmember and start bolts into frame rails by hand. Install transmission mount-to-crossmember nuts. Torque crossmember bolts and mount nuts to specification. Remove transmission jack and engine support jack.
26. 26

    Reconnect driveshaft and external connections
    Slide driveshaft into transmission tailshaft, aligning orientation marks made during removal. Install driveshaft-to-transmission flange bolts and driveshaft-to-differential flange bolts, ensuring marks are aligned. Torque fasteners to specification. Install shift tower assembly with new gasket, torquing mounting bolts evenly. Reconnect hydraulic clutch line to slave cylinder and install retaining clip. Reconnect vehicle speed sensor and reverse light switch electrical connectors.
27. 27

    Install exhaust system and perform final checks
    Reinstall exhaust system from manifolds to rear, ensuring proper hanger alignment and clearance from transmission, driveshaft, and body. Reconnect negative battery cable. Check clutch hydraulic system for leaks and proper pedal feel. Add clutch fluid if necessary and bleed system if pedal feels soft. Verify shifter operates smoothly through all gears with engine off and clutch pedal depressed.

Reassembly

1. Reassembly is detailed in steps 17-27 above and follows the reverse order of disassembly with critical attention to bearing installation, synchronizer alignment, case sealing, and proper torque specifications.
2. All gaskets, seals, and O-rings must be replaced during reassembly - reusing old seals will result in leaks.
3. Thread locker must be applied to all sensor mounting bolts and specified case fasteners to prevent loosening from vibration.
4. Gear train endplay and bearing preload must be verified during reassembly to ensure proper operation and longevity.
5. Case bolts must be torqued in proper sequence to avoid case distortion which can cause binding or bearing failure.

Verification

• With engine off and clutch pedal depressed, verify shifter moves smoothly into all six forward gears and reverse without grinding or excessive effort.
• Start engine and verify no fluid leaks from transmission case, tailshaft seal, input shaft seal, or shift tower gasket.
• With engine at idle and transmission in neutral, listen for any abnormal bearing noise or gear rattle. Some gear noise in neutral is normal for the T56.
• Test drive vehicle through all gears under light load, verifying smooth shifts and no gear clash. Check for proper clutch engagement and release.
• After test drive, recheck fluid level and inspect for leaks. Fluid level should be at bottom of fill plug hole.
• Drive vehicle 50-100 miles and recheck all mounting bolts and fluid level to ensure no loosening or leakage has occurred during break-in period.

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