The SRT-4 T850 5-Speed Manual Transmission
The manual transmission that is in the SRT-4 is the NV T850 5-speed transmission. It is a constant-mesh manual transmission that is synchronized in all gear ranges, including reverse unlike the T350 transmission, that is in all 1.6L 2.0L and 2.0 R/T cars, that isn’t synchronized in reverse. The T850 transmission consists of three major sub-assemblies; the input shaft, intermediate shaft, and differential assembly. The transmission shift system consists of a mechanical shift cover, rail, forks, and cables. The unique design of the transmission verses the others provides a higher mechanical advantage, resulting in less friction and lower shift cable loads for smoother, more positive operation. Lubrication throughout the transmission is from splashed oil collected in case passage and oil trough and distributed to mainshafts via gravity. You should ONLY use ATF+4 (Automatic Transmiision Fluid – Type 9602) and if completely empty also use 4 oz of Mopar Limited Slip Additive/Frisction Modifier. The 5 speeds of the transmission are determinded by each speed’s gear ratio. Here are the gear ratios for the T850:
Also with the 04 & 05 year models you have the Quaife Automatic Torque Biasing Limited Slip Differential (LSD). The LSD is a performance oriented unit which is designed to provide traction to both wheels during all driving condtions. Our LSD is a design that behaves like an open differential during normal driving situations. During aggressive driving maneuvers (straight line hard acceleration, hard cornering) it senses which wheel has better grip, and switches power to that wheel smoothly and consistently, without removing power from the other wheel. In technical terms, torque bias is generated by the axial and radial thrusts of the pinions in the pockets. The resultant friction force enables the driving road wheel and sun gear to transmit a greater proportion of the torque. This is a progressive action, yet at no stage will the differential ever lock. This differential also controls loss off traction when the drive wheels are on slippery surfaces, providing the appropriate traction needed to overcome these conditions of wheel slip
Removal –
1. Begin under the hood by removing the turbocharger solenoid pack from the air cleaner assembly. These are the 3 solenoids.
2. Disconnect the IAT sensor and remove the air cleaner assembly. For those of you with aftermarket intake you know what to do.
3. Remove the cold side pipe (from the intercooler to the TB)
4. Disconnect the IAC and TPS connectors.
5. Disconnect accelerator cable from the throttle body linkage.
6. Remove throttle body adapter
7. Remove the battery
8. Remove the battery tray
9. Disconnect shift cable from the transmission shift levers and bracket
It will be necessary to drain transmission fluid. Remember that you will need to add fluid.
10. Remove both front tires
11. Disconnect and remove both ABS front wheel speed sensors
-- You will now have to remove the driveline half shaft--
Some info: The SRT-4 has an equal length half-shaft system that incorporates two halfshafts assemblies that (in expert terms) consists of an inner and outer constant velocity (CV) goint and a solid interconnecting shaft, and an intermediate shaft/bearing assembly or (in simple terms) the axels. The halfshaft assemblies, or axles, are designed to transmit power from the transmission to the front wheels.
Halfshaft System:
1. You should already have both front tires removed at this time.
2. Remove the cotter pin, nut lock, and spring washer, and hub nut from the end of the outer CV joint stub axle. See Fig. 13
3. Now remove the nut and bolt retaining the ball joint stud into steering knuckle. See Fig. 14 **Note: Be careful when separating ball joint stud from the steering knuckle, so ball joint seal doesn’t get damaged.
4. Separate ball joint stud from steering knuckle by prying down on lower control arm. See Fig 15
5. Remove the halfshaft from the steering knuckle by pulling outward on knuckle while pressing in on halfshaft. Support outer end of halfshaft assembly. See Fig 16
Some transmission fluid may leak when you pull the axles out.
6. Support outer end of the halfshaft assembly. **Note: Removal of the inner joints is make easier if you apply outward pressure on the joint as you strike the punch with a hamper. DO NOT PULL ON INTERCONNECTING SHAFT TO REMOVE, AS THE INNER JOINT WILL BECOME SEPARATED.
7. Removing halfshaft(s). Left halfshaft: While applying outward pressure on joint by hand, dislodge inner tripod joint from differential side gear by striking outward with a punch. When removing tripod joint and shlfshaf, do not let spline or snap ring drag across axle seal. Right halfshaft: Slide inner tripod joint off of intermediate shaft. If difficulty is encountered, dislodge join from intermediate shaft using punch. If intermediate shaft is to be removed, remove two intermediate shaft bearing to bracket bolts. See fig 17.
You now resume the process of removing the transmission
13. Disconnect the clutch hydraulic circuit “quick-connect” fitting. See fig13
14. Disconnect back-up lamp switch connector. See fig. 14
15. Remove the starter. See fig 15
16. Remove the lateral bending brace. See fig 16
17. Disconnect the hot side pipe that bolts to the power steering lines and remove the two bolts that are hold the power steering lines.
18. Remove the structural collar. See Fig 19
19. Now be prepared, this is when the transmission will come loose from the engine. Another jack will be necessary to support the weight of the transmission.
20. Remove the four clutch-to-engine bolts. While removing the bolts, one tight-tolerance hole will be encountered. When the bolt is removed, mark driveplate (flywheel) and modular clutch assembly at this location, and be sure to align marks upon reassembly. See Fig 20
21. Now secure the transmission jack
22. Remove let mount through bolt
23. Lower engine/transmission assembly enough to gain access to left mount and bellhousing bolts.
24. Remove left mount-to-transmission bolts. Remove mount. See Fig 21
25. Now you should install another jack to support the weight of the engine after the removal of the transmission.
26. Remove transmission bell housing bolts; remove transmission and modular clutch assembly.
