BLUF: Prevent Chinook transmission corrosion during shipping by using the procedures in the IETM, TM 1-1520-271-23&P (15 Feb 23).
This article initially appeared in PS 773 (Apr 17), pp. 18-19.
Mechanics, when removing a Chinook transmission for shipment or storage, corrosion prevention is a must. Static corrosion is happening between the time a transmission is placed in a shipping or storage container and when the container is opened at the depot for overhaul.
The corrosion problem has been found in these transmissions:
| Item |
NSN 1615-01- |
| Aft transmission |
315-4071 |
| Combining transmission |
464-3974 |
| Engine transmission |
464-7113* |
| Forward transmission |
317-6446 |
To correct the problem, follow the corrosion procedures in the latest update to IETM, TM 1-1520-271-23&P (15 Feb 23).
Follow these steps before shipping a transmission:
- Check all transmission surfaces for corrosion, cracks, chipped paint and bare surfaces.
- Spray corrosion preventive compound (CPC) onto corroded surfaces, areas of chipped paint, exposed metal and into visible cracks.
- Put the transmission into its shipping and storage container.
Make a note that the CPC in the expendable materials section of the TM is an improved formula. Check out the chart below:
| TM 1-1520-271-23&P, CH-47F |
| Item |
Old NSN/PN |
New NSN/PN |
Qty |
| E156 |
8030-01-347-0979 (MIL-DTL-85054C) |
8030-01-347-0980 (MIL-DTL-85054) |
11-oz Can |
| E157 |
8030-01-347-0980 (MIL-DTL-85054C) |
8030-01-347-0981 (MIL-DTL-85054) |
1 quart |
When spraying CPC, be aware of the product warnings and cautions and always make sure you wear the proper safety and breathing equipment.
WARNING
Aerosol, MIL-DTL-85054, is flammable and toxic. In can irritate skin and cause burns. Use only in a well-ventilated area, away from heat and open flame.
In case of contact, immediately flush affected skin and eyes with water for at least 15 minutes. Get medical attention for eyes. Ensure you read and understand the safety and data sheet (SDS).
CAUTION
Aerosol, MIL-DTL-85054, is not compatible with corban-35! Mixing will compromise the corrosion protection required.
Editor’s Notes:
* This NSN has been updated from the original article.
Other minor changes have been made to reflect the fact that information contained in a maintenance action message has now been incorporated into the TM. Also, references to the CH-47D have been removed.