We offer a duralumin gearbox lower cover as a solution to this problem. Available in our online shop.
Drain Plug Thread Damage
During an oil change on the Ferrari 360, there are reported cases of the gearbox drain bolt thread stripping when tightened.
The cause is always overtorquing, but there are a few reasons why this tends to happen.
Torque Spec in the Service Manual
Some Ferrari 360 service manuals list the drain plug torque specification as 75 Nm.
However, the generally accepted torque range for drain bolts on aluminum blocks is around 25–35 Nm. At roughly twice that value, 75 Nm is a significant overtorque.
Why this figure appears in the manual is unclear, but cases of lower cover thread damage caused by following the manual spec have been reported.
Insufficient Thread Strength of the Lower Cover
The factory lower cover is made using aluminum die casting — a process where molten aluminum is poured into a mold to form the part.
Die casting has an inherent weakness: small amounts of moisture and air can mix into the molten material during production, creating microscopic voids (air pockets) inside the finished part. These voids reduce the overall strength of the material.
Thread areas are particularly vulnerable, as repeated tightening concentrates stress in a small area. When internal voids are present, this can lead to cracks or complete thread failure. This is the reason why aluminum die-cast lower covers are known for stripped threads.
Our Solution: Gearbox Lower Cover (F0136)
Italy Car Parts offers a lower cover machined from A7075 duralumin — a high-strength aluminum alloy also used in aerospace applications — as a direct solution to thread stripping issues.
Manufacturing: CNC machined (domestic factory · Made in Japan)
Set includes: Lower cover / Drain plug (magnetic type) / Washer
OEM part number: 171045
Compatible vehicles: Ferrari 360 Modena / 360 Spider / 360 Challenge / 360 Challenge Stradale
OEM vs. Duralumin Comparison
| OEM (Die Cast) | Duralumin | |
|---|---|---|
| Material | Aluminum die cast | A7075 Duralumin |
| Manufacturing | Die casting (mold poured) | CNC machined |
| Internal void risk | Yes | No |
| Thread strength | Low | High |
| Made in | Italy | Japan |
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Email: importparts@italycar.jp
