A/T - Harsh Gear Engagement
Bulletin 87-7125-3ADate July '87
Ref. No. 87-117A-7125
Corp. Ref. No. 777124
SUBJECT: NEW FORWARD CLUTCH ASSEMBLY AND NEW LO AND REVERSE CLUTCH ASSEMBLY TO IMPROVE HARSH GARAGE SHIFT FEEL
NOTICE: This bulletin supersedes bulletin 87-7125-3, dated May, 1987, to correct Forward Clutch Assembly - complete part number.
MODELS AFFECTED: ALL 1985-1987 CENTURYS, SKYHAWKS, SOMERSETS, AND SKYLARKS EQUIPPED WITH THM-125C (MD9)
BULLETIN COVERS:
New forward clutch assembly, including: a new housing, piston, selective backing plates, and an additional wave plate for improved neutral to drive shift feel.
New lo and reverse clutch housing and lo and reverse clutch pack assembly, including: a new housing, piston, two wave plates, and selective backing plates for improved neutral to reverse shift feel.
FIGURE 1 - THM 125/125C TRANSAXLE IDENTIFICATION INFORMATION:
DATE OF CHANGE (Figure 1) The new forward clutch assembly implemented July 3, 1986, (Julian date 184), and the new lo and reverse assembly implemented July 8, 1986, (Julian date 189) for all models of the THM 125C.
SERVICE ACTION
1985 and/or 1986 Model Year:
The neutral to drive package can be used to service a 1985 or 1986 (before Julian date 184) THM 125C transaxle exhibiting a harsh drive engagement by replacing the forward clutch with the new forward clutch assembly.
The neutral to reverse package can be used to service a 1985 or 1986 (before Julian date 189) THM 125C transaxle exhibiting a harsh reverse engagement by replacing the lo and reverse clutch assembly with the new lo and reverse housing assembly, and new lo and reverse clutch pack assembly. (The lo and reverse clutch pack assembly contains both wave plates, the steel and composition-faced plates, and the correct selective backing plate.)
1986 and/or 1987 Model Year:
When servicing the forward and/or lo and reverse clutch assemblies on a 1986 (after Julian date 184) or 1987 THM 125C transaxle, it is important to select the correct backing plate. The backing plate selection effects piston travel and shift feel.
FIGURE 2 - FORWARD CLUTCH BACKING PLATE SELECTION:
To check the forward clutch backing plate selection, apply approximately 10 lbs. of pressure on the backing plate and check the gap between the backing plate and snap ring. If the gap is larger than 1.49 mm (.052"), use the next thicker backing plate, and if smaller than 0.67 mm (.023"), use the next thinner backing plate. Refer to Figure 2 for alternate backing plate selections.
The new lo and reverse clutch pack assembly (wave, steel, compositioned-faced, and selective backing plate) is serviced as an assembly only.
SERVICE PARTS INFORMATION
8664167 Forward Clutch Assembly, Complete
8664152 Lo and Reverse Clutch Housing Assembly
8664151 Lo and Reverse Clutch Pack Assembly