Revisions to this document are noted
by a stripe in the left-hand margin

SUBJECT:

SIL 28-WT-18, Rev. A
January, 2019
Page 1 of 5

Changes to Torque Converter Turbine Hub Sealrings

MODELS AFFECTED:

3000 Series Product Family and 4000 Series Product Family

SERIAL NUMBERS AFFECTED:

S/N 6511577642 – 3000 Series, Plant 6, Indianapolis
S/N 6610528524 – 4000 Series, Plant 12, Indianapolis
S/N 6520208090 – TC419 3000 Series, Hungary Plant
S/N 6520208124 – TC418 3000 Series, Hungary Plant
S/N 6520209722 – TC421 3000 Series, Hungary Plant
S/N 6520209935 – TC418D 3000 Series, Hungary Plant
S/N 6620032784 – TC571 4000 Series, Hungary Plant
Note: Remaining Hungary S/N breaks will be updated with next SIL revision.

Introduction:
Turbine hub sealrings found in 3000 and 4000 Product Family torque converters are changing from a hook-type,
cast iron design to a butt-joint, polymer design.
New polymer sealrings are backward compatible.
New sealring part numbers have been released; P/N 29559230 for 3000 Series Product Family and P/N 29559682
for 4000 Series Product Family. See Figure 1 for former and current part numbers and design features.
NOTE: Figure 1 does not show the sealring properly hooked so you can depict the design.

Part numbers for torque converter assemblies, turbine assemblies and service kits that contain the new turbine
sealring will not change.

Table 1. Part Numbers Associated with Sealring Changes
Former

New

Cast Iron, Hook-type

Polymer, Butt-joint

JT / SL8214EN

4424330

Copyright © 2018 Allison Transmission, Inc. All Rights Reserved.

SIL 28-WT-18, Rev. A
January, 2019
Page 2 of 5

Table 1. Part Numbers Associated with Sealring Changes (cont'd)
Former

New

Sealring, 3000 Series

29500025

29559230

Turbine Assembly, 3000 Series

29503979

29503979

Sealring, 4000 Series

29501318

29559682

Turbine Assembly, 4000 Series

29506620

29506620

Parts Identification:

Figure 1. Torque Converter Turbine Hub Sealrings
Plant 12 (Indianapolis) implemented the polymer sealring (P/N 29559682) in 4000 Series Product Family of
transmissions on 8/8/2018, starting with S/N 6610528524. All 4000 Series transmissions assembled on 8/8/2018
or later contain this new sealring.
Plant 6 (Indianapolis) implemented the polymer sealring (P/N 29559230) in 3000 Series Product Family of
transmissions on 9/5/2018, starting with S/N 6511577642. All 3000 Series transmissions assembled on 9/5/2018 or
later contain this new sealring.

Copyright © 2018 Allison Transmission, Inc. All Rights Reserved.

SIL 28-WT-18, Rev. A
January, 2019
Page 3 of 5

Service Kits:
Service kits that support both 3000 and 4000 Series products are also being updated with the respective poly
sealring. As Allison Parts Distribution Center (PDC) exhausts service kits that contain the former sealring,
replacement kits will be assembled using the new sealring. Efforts have been made to transition kit stock near the
time of new production. See Table 2 for affected kit part numbers.
Cast iron hook-type sealring is being replaced with the new, polymer butt-joint sealring in the following service
kits. As kits are assembled at PDC, they are labeled with a build date (see Figure 2). Kits with a label dated after
9/18/18 contain the new butt-joint, polymer sealring.
Return of existing service kits is acceptable, provided it follows the details outlined in Transmission Parts Policy
Letter 06-TPPL-07 (latest revision).
The former cast iron sealrings have been completely cancelled, considered as inactive, and not returnable.
Table 2. Service Kits with New Polymer, Butt-joint Sealring
Product

Kit P/N

Description

3000

29546239

WTEC Straight-through Seal & Gasket Kit

3000

29548989

Master Overhaul Kit For WTEC III Controls Only

3000

29550017

Straight Through Seal & Gasket Kit, 4th Gen

4000

29546245

WTEC Complete Straight-through Seal & Gasket Kit

4000

29546246

Complete Retarder Seal & Gasket Kit

4000

29559770

Complete Overhaul Kit - 4700/ 4800 Series 7-speed without Retarder. Use Kit with
TIDA or TIDB

4000

29559771

Complete Overhaul Kit - 4700/ 4800 Series 7-speed with Retarder. Use Kit with TIDA
or TIDB

4000

29559772

Complete Overhaul Kit - 4000 Series 6-speed without Retarder, with Prognostics
(MY09). Use Kit with TIDA or TIDB

4000

29559773

Complete Overhaul Kit - 4000 Series 6-speed with Retarder and Prognostics (MY09).
Use Kit with TIDA or TIDB

Copyright © 2018 Allison Transmission, Inc. All Rights Reserved.

SIL 28-WT-18, Rev. A
January, 2019
Page 4 of 5

Figure 2. Kit Label with Build Date Shown

Installation:
Be sure to follow the appropriate Allison Service Manual instructions for wear limit measurements, proper
inspection of turbine hub groove and mating components, along with proper installation of replacement sealring.
No specific sealring orientation is needed for installation. Install sealring in its natural state over the turbine
hub, into the turbine hub groove as shown in Figure 3.

Figure 3. Installed Polymer Sealring on Turbine Hub
No special tools are required to properly install the new sealrings.
Butt-joint sealrings require special handling during assembly.
1. Place the new sealring in its operational position inside the front cover bore that it will be sealing.
Copyright © 2018 Allison Transmission, Inc. All Rights Reserved.

SIL 28-WT-18, Rev. A
January, 2019
Page 5 of 5
2. Measure ID of sealring while located in the front cover bore and compare measurement to wear limit data in
Service Manual to determine if cover can be re-used.
3. Compress the sealring to about half its free diameter and hold it for about 10 seconds.
4. Slide sealring onto the turbine hub, being careful not to spread the sealring more than necessary.
5. Place one end of the sealring into the turbine hub groove and gradually work the sealring into the groove.
6. Pack the sealring and its groove with a liberal amount of oil soluble grease to better hold sealring in turbine
hub groove.

Copyright © 2018 Allison Transmission, Inc. All Rights Reserved.