M/T - Crunching Shifting From 2nd to 3rd Gear
91ford24
Article No. 91-18-11
09/05/91
^ NOISE-INTERMITTENT "CRUNCHING" WHEN SHIFTING FROM 2ND TO 3RD-VEHICLES WITH M50D (MAZDA R1 AND R2) TRANSMISSION
^ TRANSMISSION-M50D (MAZDA R1 AND R2)- INTERMITTENT "CRUNCHING" NOISE WHEN SHIFTING FROM 2ND TO 3RD
LIGHT TRUCK: 1988-89 ECONOLINE
1988-90 BRONCO II
1988-91 AEROSTAR, BRONCO, F-150, RANGER
1991 EXPLORER
ISSUE: A slight intermittent "crunch" or grinding noise may be heard when shifting from 2nd to 3rd. This is caused by improper synchronizer engagement.
ACTION: Install a new synchronizer service kit. Refer to the Parts Block for correct parts usage and the following procedure for service details.
INSPECTION
1. Drive the vehicle to warm the transmission oil temperature to about 125~F (52~C). This can usually be done after driving about 10 miles at highway speed when the outside temperature is above freezing.
2. On a smooth road surface, accelerate the vehicle from a stop to 3rd gear at normal shift speeds as defined in the owners guide.
3. If a slight "crunch" is heard or grinding sensation is felt in the shift lever when shifting from 2nd to 3rd, proceed with the following synchronizer kit installation procedure.
SYNCHRONIZER KIT INSTALLATION
1. Remove the transmission from the vehicle. Refer to the appropriate Light Truck Shop Manual, Section 07-03A, for removal procedure.
2. Remove the 1st/2nd and 3rd/4th clutch hub and sleeve assembly along with the corresponding synchronizer ring.
3. Install all parts from the appropriate synchronizer kit. The kits contain new 1, 2, 3, and 4 synchronizer rings, a new 3/4 synchronizer sleeve and an instruction sheet. The original 1/2 clutch hub sleeve assembly and 3/4 clutch hub must be reused.
4. Put a label on the transmission showing it was updated per TSB 91-18-11 and to refer to this TSB before servicing.
NOTE: THE NEW 3RD GEAR SYNCHRONIZER RING AND 3/4 SYNCHRONIZER SLEEVE ARE UNIQUE FROM THE ORIGINAL COMPONENTS. THE NEW COMPONENTS MUST BE INSTALLED AS A SET IN THE PROPER POSITION. FAILURE TO DO SO WILL RESULT IN THE INABILITY TO SHIFT THE TRANSMISSION INTO ONE OF THE GEARS. note>
PART NUMBER PART NAME CLASS
FOTZ-7C391-H Synchronizer Kit - R2 (F-150, C
Bronco, Econoline)
FOTZ-7C391-F Synchronizer Kit - R1 (Ranger, C
Bronco II, Explorer)
FOTZ-7C391-G Synchronizer Kit - R1 C
(Aerostar)
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under Basic Warranty
Coverage, Powertrain
Warranty Coverage
OPERATION DESCRIPTION TIME
911811A Inspect Transmission 0.3 Hr.
911811B Install Synchronizer Kit 5.0 Hr.
Ranger 4X2 With 2.OL,
2.3L, 2.9L, or 3.OL And
Aerostar With 3.OL
911811C Install Synchronizer Kit 6.7 Hr.
Ranger 4X4 With 2.3L or
4.OL and Explorer 4X4
911811D Install Synchronizer Kit - 6.9 Hr.
Ranger 4X4 With 2.9L
911811E Install Synchronizer Kit - 6.0 Hr.
Ranger 4X2 And Explorer
4X2 With 4.OL
911811F Install Synchronizer Kit - 6.5 Hr.
Bronco II 4X2 With 2.9L
And Bronco With 5.OL
911811G Install Synchronizer Kit - 6.9 Hr.
Bronco II 4X4 With 2.9L
911811H Install Synchronizer Kit 5.1 Hr.
F-150 4X2 With 4.9L
911811I Install Synchronizer Kit 6.3 Hr.
F-150 4X4 With 4.9L or
5.OL And Bronco With 4.9L
911811J Install Synchronizer Kit - 5.3 Hr.
F-150 4X2 With 5.OL
911811K Install Synchronizer Kit - 5.2 Hr.
Econoline With 4.9L
DEALER CODING
BASIC PART NO. CONDITION CODE
7C391 56
OASIS CODES: 505000, 505200, 506000, 702000