Transaxle Refinements
OIL PUMPA revised oil pump housing and a changed reaction support casting released in July of 1992 for the 1993 model year. The changes occurred to extend the cavitation point of the pump to higher engine speeds. The new pump assembly services the (P/N 4567862).
LOW/REVERSE PISTON
The low/reverse piston outer diameters are reduced by 0.04" to eliminate potential thermal binding in the retainer. The casting tab was moved 1 mm (0.0394"). The part number did not change and the old and new parts are interchangeable. The change occurred in July of 1992 for the 1993 model year.
EXTENSION HOUSING AND BEARING RETAINERS
Reference: TSB 08-39-93
The speedometer pinion bore was removed from the extension housing. The change to the extension housing began in July of 1992 for the 1993 model year. This eliminates the speedometer pinion, vehicle speed sensor and associated hardware. The output speed sensor is used to send a signal directly to the TCM for vehicle speed. All 41 TE transaxles now use the extension without the speedometer bore. The new extension does not service the old. The TCM is programmable with a "Pinion Factor" to calculate vehicle speed.
ACCUMULATOR SPRINGS AND PISTONS
Reference: TSB 21 -37-93
The inner accumulator spring changed in July 1992 for the 1993 model year. The new spring replaces the old spring with part number 4471881. The new spring is required in all 1993 model year low/reverse and 2-4 accumulators. The Low/reverse accumulator is in the case and the 2-4 is in the valve body. The springs are shot peened and chamfered to increase durability.
Some applications require a new outer spring (green) and a plain inner spring for the underdrive spring only. The change is to provide enhanced neutral-to-drive shift quality. Part numbers are:
- Overdrive Clutch Outer Accumulator Spring = 4659124 (green)
- Overdrive Clutch Inner Accumulator Spring 4567575 (plain)
PARK SPRAG GUIDE BRACKET
The park sprag guide bracket had slight modifications in July of 1992 for the 1993 model year to allow the guide bracket to be common with the 42LE guide bracket. The guide bracket was designed to allow easier rod installation on 42LE transaxles. The new guide bracket services the old.
OIL PUMP SEAL
An orange ink coating was applied to the outer diameter oil pump seal in February of 1993. The coating is to prevent seal twist during production installation. A twisted seal is easily identified by the orange coating on one side of the seal. If the seal is twisted, black will be visible instead of orange. There was no change to pump seal dimensions.
AWD BEARING RETAINER
The AWD bearing retainer is made in two pieces beginning in April of 1993. Required with the bearing retainer is an additional O-ring on the outside diameter of the retainer for sealing purposes. The current O-ring (P/N 4486042) is carry-over for this bearing retainer assembly. The new components service the old and the part numbers are as follows:
- Plate Trans. Retainer = 4518633 (new), 4518188 (old)
- Bearing Assembly Cup = 4518632
- Bearing Assembly Cone = 4567382 (new), 4486096 (old)
- O-ring = 650011
OVERDRIVE HUB AND SHAFT
A faster machining process is used on the overdrive shaft spline and was implemented in July of 1993. The new services the old if a new front carrier is also used.
ROOSTER COMB AND INSULATOR
The insulator tabs on the edge of the rooster comb were increased in width to accommodate the electronic PRNDL display. The plastic insulator was modified to allow for wider tab slots and was released in July of 1993.
TORQUE CONVERTER
The torque converter clutch was changed to a bonded clutch disc from a free-floating clutch disc. This occurred in November 1993 for the 10" converter and in April of 1994 for the 9.5" converter and was done to enhance durability.
SNAP RING
For the 1993 model year a new UD/OD reaction plate tapered snap ring is used to enhance durability. Also, a redesigned UD/OD reaction plate (P/N's 456740, 641, 642, 643) is used to accommodate the snap ring. The new 0.16" snap ring services the old if a new reaction plate is also used.
DIFFERENTIAL ASSEMBLY
Two new gear tooth combinations were released for 1993 FWD and AWD differential assemblies. The matched gear set combinations are 59/17 and 60/16. The new differential assemblies service the old. The matched set part numbers are as follows:
- FWD 59/17 = 4567561 (new), 4531990 (old)
- AWD 59/17 = 4567859 (new), 4531996 (old)
- FWD 60/16 = 4567542 (new), 4531993 (old)
- AWD 60/16 = 4567860 (new), 4531999 (old)
Also released for 1993 is a differential assembly with high intensity shot peening. It is used with 3.8L engine applications. The shot peening process was implemented to enhance durability. To identify this assembly, look for two grooves in the side of the differential ring gear and one groove in the side of the pinion gear on the transfer shaft. The part number for the matched set assembly is 4659178 with a ratio of 60/16.
TCM PINION FACTOR
Reference: TSB 0&-39-93
For the 1993 model year, when installing a replacement TCM, it is necessary to set the "pinion factor". Use the DRB Scan Tool or MDS to set "pinion factor" so that the speedometer indicates correct mph. Select the proper axle ratio while performing the DRB or MDS steps.
TCM QUICK LEARN
The "quick learn" function applies to all vehicles if flashed properly, and later, model year vehicles with the 41TE transaxle. This option is not available for prior model year vehicles. Introduced in 1993, the quick learn function customizes or adapts the TCM to the particular characteristics of the vehicle's transaxle. Quick learn provides enhanced initial shift quality after transaxle or TCM service, compared to the initial programmed parameters stored in the TCM.
The quick learn function should be performed under the following conditions:
- Upon installation of new service TCM
- After replacement or rebuild of internal transmission components or the torque converter
TRANSAXLE SYMPTOM - HARSH SHIFTS
Reference: TSB 21 -36-93 and 08-07-94
Harsh engagement occurs with tip-in during low speed 2-1 downshifts, low-speed harsh 2-1 kickdown shifts, harsh 3-2 and 4-3 coastdown shifts, harsh 3-4 upshifts, harsh stationary neutral/drive garage shifts, park-to-reverse noise (grunt) in 1993 FWD vehicles and some 1994 vehicles. The proper repair is to use the DRB Scan Tool to diagnose and repair any diagnostic trouble codes or service any engine or transaxle related problems. If no trouble codes are present and all systems are functioning as designed, replace the TCM, change the transmission fluid, set the pinion factor (in TCM) and perform a transaxle quick learn.
TRANSAXLE GEAR RETAINING STRAP
Reference: TSB 21 -34-93
Beginning in November 1993, 41TE transaxles used with the FWD 3.8L engine or AWD Town & Country/Caravan/Voyager have a stirrup (P/N 4567263) and retaining strap (P/N 4659134) that is attached to the output gear with two bolts (P/N 6503355) (fig. 19). The stirrup, strap, and bolts prevent the output gear retaining bolt from turning and backing out of the rear carrier. These additional output gear retaining parts are required because of the additional thrust loads from the new quiet 32 degree helix angle transfer gears and the high output 3.8L engine.
OWNERS MANUAL CHANGES
Reference: TSB 21 -09-93
The transmission gear selection and operating instructions listed in the Owner's Manual for all vehicles equipped with automatic transaxles or transmissions have been revised. The changes in the Owner's Manual were made to provide more precise transaxle/transmission control (especially in moderately steep terrain), the advantage of engine braking while descending grades, and to reduce the chance of engine overheating.
The revised instructions in the Owner's Manual are identified below:
1. Park ("P") - Supplements the parking brake by locking the transaxle. Engine can be started in this range. Never attempt to use PARK while vehicle is in motion. Apply parking brake while leaving vehicle in this range.
2. Reverse ("R") - Shift into this range only when the vehicle has come to a complete stop.
3. Neutral ("N") - Engine may be started in this range. Use this range for starting your vehicle if it is moving or being towed.
4. Overdrive ("OD") - This range should be used for most city and highway driving. It provides smoothest upshifts and downshifts and the best fuel economy.
5. Drive ("3") - This range should be used for descending hills. The shift schedules in this range provide improved engine braking and vehicle performance at the expense of fuel economy. The transaxle will not shift into overdrive when this range is selected. Under certain conditions, this eliminates frequent shifting between third gear and overdrive.
6. Low ("L') - This range should be used for maximum engine braking when descending steep grades. In this range, upshifts will occur only to prevent engine overspeed while downshifts occur as early as possible.