Manual Transmission/Transaxle: Description and Operation
DESCRIPTIONFig. 1:
This five speed is a constant-mesh manual transaxle. All gear ranges, except reverse, are synchronized. The reverse gear utilizes a brake and blocking ring for shifting ease. The reverse idler gear is supported on a sliding spindle idler shaft. The transaxle case is aluminum with a steel end-plate bearing cover. It is housed in a die-cast aluminum case featuring a two-piece, middle split design (Fig. 1).
The NV T350 (A-578) transaxle internal components can be serviced only by separating the gear case from the bell housing case.
CAUTION: The transaxle output shaft is serviced as a unit. No disassembly and reassembly is possible. Damage to the transaxle may result.
TRANSAXLE IDENTIFICATION
Fig. 2:
Fig. 3:
The transaxle model, assembly number, and build date are on a metal I.D. tag that is attached to the end cover of the transaxle (Fig. 2). This information is also shown on a bar code label that is attached to the front of the transaxle (Fig. 3).
NOTE: Transaxles use various final drive gear ratios in different vehicle applications. Therefore, it is necessary that the correct transaxle assembly number is used when ordering service parts.
The last eight digits of the Vehicle Identification Number (VIN) are stamped on the case, below the back-up lamp switch.
NOTE: There are four different versions of this transaxle. There are no external differences between the models. Refer to the identification tag on the transaxle to determine which transaxle the vehicle is equipped with.
GEAR RATIOS
CAUTION: All gears and shafts must not be interchanged with other transaxles; they will not function correctly.
The differential is a conventional arrangement of gears that is supported by tapered roller bearings. The final output gear turns the ring gear and differential assembly, thereby turning the drive axle shafts.
All JA transaxles have a torque capacity of 136 lb. ft. The gear ratios of each transaxle are shown in the following chart. The chart also shows which transaxles are available with the reverse-input shaft brake. This brake allows easier shifting into reverse and helps eliminate reverse gear clash.
GEARSHIFT PATTERN
Fig. 4:
The NV T350 (A-578) transaxle shift pattern is a modified H-pattern (Fig. 4). Overdrive fifth and reverse gears are in-line and outboard of the first through fourth gear positions.
LUBRICANT ADDITIVES
NV T350 (A-578) transaxles use Mopar Type M.S. 9417 Manual Transaxle Fluid. Hypoid gear lube, engine oil, and/or automatic transmission fluid should not be used in this transaxle. Hard shifting effort, bearing, gear, and/or synchronizer failure may occur if incorrect fluid is used.
The addition of any fluids to the transaxle, other than the fluid listed above, is not recommended. An exception to this policy is the use of special dyes to aid in detecting fluid leaks. The use of transmission sealers should be avoided, since they may adversely affect seals.
SEALANTS
The sealant used to seal the transaxle case halves and input bearing is Mopar Gasket Maker, Loctite 518, or equivalent. The sealant used for the bearing end plate cover is Mopar RTV.