PERFORMANCE
H I GH PE R FOR MANCE TRANSMISSIO N PARTS
Instructions
GM Powerglide®
10-Clutch Drum Kit
Part No.
Shim,
Wide
28756-08K
•10-Clutch Drum
•10-Clutch Piston
•Bushing PTFE-Coated
•10-Clutch Hub
•High Clutch Return Springs (24)
•Clutch Drum Spring Retainer
•Retaining Ring
Large
•Retaining Ring
Small
•Wear Plate
Large
•Wear Plate
Small
•Lip Seal
Large
•Lip Seal
Small
•Frictions (10)
.060"
•Kolene® Steels (10)
24-Tooth
•Thrust Bearing
•Shim, Wide
•Shim, Narrow
6 Extra
•Rubber Bumpers (60)
Not Shown
Shim,
Narrow
PTFECoated
Bushing
Thrust Bearing
10-Clutch Drum
Frictions
(10)
24-Tooth
Kolene® Steels
(10)
10-Clutch Hub
Lip Seals
(Large
& Small)
Large Wear Plate
Large Retaining Ring
10-Clutch Piston
Clutch Drum
Spring Retainer
Small Wear
Plate
High Clutch
Return Springs (24)
Small
Retaining Ring
Patent Nos. 6,920,970 & 7,204,357
To ensure maximum clutch plate engagement with the hub splines, Sonnax 10-clutch hubs are manufactured with a minimal chamfer
at the indicated area. When using non-Sonnax flanges, you must check the clearance between the chamfer on the hub and the sun gear
CAUTION
flange to ensure there is adequate clearance. If more clearance is needed, machine a greater chamfer on the hub as necessary.
NOTES & CAUTIONS:
• If pump has been previously machined at thrust washer/
bearing face to accept a bearing, and previously used a drum
that is NOT machined, install Sonnax .046" thick wide
pump shim between bearing and pump.
• If pump has not been machined at thrust washer/bearing face,
install Sonnax drum and included bearing. Discard Sonnax
.046" thick wide pump shim.
• Check clutch hub endplay. If excessive, install shim between
small wear plate and drum to keep hub located closer to
flange and ensure full clutch spline engagement with top of
clutch hub. Some clutch hub endplay is required.
CAUTION
Minimal Chamfer
Check for clearance.
Flange
Wear Plate
Clutch Hub
Shim
Small Wear
Plate
• A clutch stack up with 10 frictions requires the top friction
to run against sun gear flange plate. When using non-Sonnax
flanges, ensure the flange surface is smooth enough to run
friction material directly on the flange surface (generally Ra
20 or better).
• If sun gear flange plate is NOT suitable for running friction
material directly on flange surface, replace top friction with
steel plate for a total of nine frictions and 11 steel plates.
©2017 Sonnax Industries, Inc.
800-843-2600 • 802-463-9722 • F: 802-463-4059 • www.sonnax.com
Sonnax 10-Clutch Drum
28756-08K-IN 03-02-17
Page 1
PERFORMANCE
H I GH PE R FOR MANCE TRANSMISSIO N PARTS
Instructions
10-CLUTCH DRUM KIT WITH BEARING 28756-08K
When using the anti-drag rubber bumpers, it is best to have the input shaft
supported with a bushing at the front of the stator tube.
Figure 2
If the input shaft is not supported with a bushing at the front of the stator tube, accumulated
tolerances and clearances can allow the input shaft and high clutch hub can move off center.
This will result in the clutch plates contacting the anti-drag rubber bumpers, damaging the
bumpers and potentially causing clutch pack failure.
1. Assemble Piston
Assemble piston, seals, return springs and retainer using normal assembly procedures.
2. Install Rubber Bumpers
Install six anti-drag rubber bumpers into the holes (Figure 2) on nine of the 10 steel
plates. Take care when installing the rubber bumpers to not tear or damage the
rubber. Six extra bumpers are included in this kit.
2. Load Drum
When loading the drum, the first steel against the piston should have no rubber
bumpers. Stack the remaining clutches and steel plates, alternating the position of
the rubber bumpers (Figure 3), so that no bumpers are stacked on top of each other.
Figure 3
Rubber Bumper
NO bumpers on first steel.
©2017 Sonnax Industries, Inc.
800-843-2600 • 802-463-9722 • F: 802-463-4059 • www.sonnax.com
28756-08K-IN 03-02-17
Page 2