A/T - Forward Sprag Clutch Service Information

Number 83-I-136 Section 7 Date 08/83
Subject: SERVICE INFORMATION FOR THE FORWARD SPRAG CLUTCH - THM 700-R4 (ALL)

Beginning May 3, 1982, a new forward sprag clutch entered production replacing the forward roller clutch on all THM 700-R4 transmissions.

To minimize the number of service parts required in inventory, only the new forward sprag clutch parts are serviced as follows:

Figure 1:

A.. If any of the following parts require replacement on a transmission built with a roller clutch, order service package 8642947 (see Figure 1).

Hub, Overrun Clutch (#2) Race, Forward Clutch-Outer (#5)
Cam, Forward Roller (#3) Gear, Input Sun (#6)
Roller Assembly, Forward Clutch (#4) Carrier Assembly, Input-Complete (#8)

NOTICE: Overrun Clutch Hub Retaining Snap Ring (#l) and Input Carrier To Race Thrust Washer (#7) still available individually for service (see "B." on reverse side).

Figure 1:

Service package 8642947 is a sprag conversion kit which contains the following parts (refer to Figure 1):

Snap Ring, Overrun Clutch Hub Retaining (#638) Race, Forward Clutch-Outer (#644)
Hub, Overrun Clutch (#639) Gear, Input Sun (#658)
Wear Plate, Sprag Assembly (#640) Washer, Thrust (Input Carrier To Race) (#660)
Retainer & Race Assembly, Sprag (#641) Carrier Assembly, Input-Complete (#662)
Forward Sprag Assembly (#642) Instruction Sheet

B. The following individual part numbers can be used to service all transmissions which either were built with a forward sprag clutch after May 3, 1982, or have been converted with service package 8642947.

a. 8647083 - Snap Ring, Overrun Clutch Hub Retaining (#638)
b. 8647082 - Hub, Overrun Clutch (#639)
c. 8647081 - Wear Plate, Sprag Assembly (#640)
d. 8647085 - Retainer & Race Assembly (#641)
e. 8647084 - Forward Sprag Assembly (#642)
f. 8647090 - Race, Forward Clutch-Outer (#644)
g. 8647093 - Gear, Input Sun (#658)
h. 8647095 - Washer, Thrust (input Carrier To Race) (#660)
i. 8647050 - Carrier Assembly, Input-Complete (#662)

SERVICE INFORMATION

1. Use the following procedure to assemble the forward sprag clutch.

a. Place the forward clutch outer race (#644) on table with the recessed face down.

Figure 2:

b. Hold the forward sprag assembly (#642) (without brass retainer rings, #643) in your right hand. The crossbar notches in the sprag cage must point to the left as viewed in Figure 2 (below).

c. Install the sprag into the forward clutch outer race. Now, install a brass retainer ring (#643) on the sprag case. When properly installed, the flanges of the retainer ring (#643) will face the sprag cage (refer to Figure 2).

Figure 3:

d. Install the retainer and race assembly (#641) into the sprag by pushing downward and rotating counterclockwise (see Figure 3 below).
e. Turn the assembly over and install the remaining brass retainer ring (#643) on the sprag cage.

f. Install the wear plate (#640) on top of the brass end cap. Place the overrun clutch hub (#639) on the wear plate; (#640) engage the tangs; and, insert the snap ring (#638) to retain it.

Figure 4:

g. Now, check for proper assembly as shown in Figure 4.
2. Some of the parts associated with the roller clutch are similar in appearance to the sprag clutch parts.. If these parts are ever mixed, use the following information to identify which parts are roller design and which parts are sprag design. (First design refers to roller clutch parts and second design refers to sprag clutch parts.)

Figure 5:

a. Overrun Clutch Hub (#639) - See Figure 5. First Design - Face of tangs was flat.
Second Design - High spot on each tang.

Figure 6:

b. Outer Race Forward Clutch (#644) - See Figure 6 First Design - Lube hole in race. Second Design - Lube hole in shoulder.

Figure 7:

c. Input Sun Gear (#658) - See Figure 7. First Design - One (1) lube hole and higher shoulder. Second Design - Four (4) lube holes and lower shoulder.
NOTICE: Do not mix any roller clutch design parts with sprag clutch design parts as they are not interchangeable. If these parts are mixed, premature wear will be experienced.