Gasket and seal kit only. Bearings, clutch discs and other mechanical rebuild components are not included.
The Muncie A20-GSK gasket and seal kit groups replacement sealing components for A20 Series power take-off service. Use it when the repair calls for seals and gaskets, after checking the condition of the remaining PTO components.
A20-GSK is already included in A20-RBK-05A and A20-RBK-07A rebuild kits. If you are purchasing either rebuild kit for the same repair, avoid ordering a duplicate sealing kit unless additional parts are needed.
Sealing components in one service kit
O-rings, shaft seals, a ring seal and the transmission mounting gasket are supplied together, making it easier to plan a resealing job. Match the individual parts to the PTO configuration and service procedure before installation.
Technical specifications
| Specification |
Detail |
| Manufacturer part number |
A20-GSK |
| PTO series |
Muncie A20 |
| Kit type |
Gaskets and seals |
| Transmission mounting gasket |
13T35777 Allison 10-bolt gasket |
| Included in rebuild kits |
A20-RBK-05A and A20-RBK-07A |
Kit contents
Quantities below are included in one kit.
| Component and quantity |
Part number |
| O-ring — 1 |
12T36472 |
| O-rings — 2 |
12T36869 |
| Ring seal — 1 |
12T42978 |
| O-rings — 2 |
12T39023 |
| O-ring — 1 |
12T36701 |
| Small shaft seal — 1 |
11T38247 |
| Large shaft seal — 1 |
11T64141 |
| O-ring — 1 |
12T34003 |
| O-ring — 1 |
12T43185 |
| Allison 10-bolt gasket — 1 |
13T35777 |
Before ordering
| Check |
Ordering guidance |
| PTO identification |
Confirm the complete A20 model and output configuration. |
| Repair scope |
Determine whether sealing parts alone address the repair or mechanical components are also needed. |
| Existing rebuild-kit order |
A20-GSK is included in both A20 rebuild kits listed above. |
| Seal placement |
Match each component to its location using the applicable A20 service instructions. |
Installation and service documents
Review the Muncie A20 PTO Rebuild Instructions (PDF — IN21-06) for disassembly, inspection and reassembly procedures.
Need help selecting the correct PTO seal kit? Contact UnitedBuilt through online chat, email parts@unitedbuilt.com, or call 602-253-7750 with your complete PTO model, output configuration and a photo of the identification tag.
