Piaggio 840439 Transmission Cover Cap – Beverly, MP3, X9, Nexus 400/500

The Piaggio 840439 is the transmission cover cap, the plug that closes the inspection opening on the transmission casing. It is the original spare part provided for almost all 400 and 500 cc maxi-scooters of the Piaggio Group: Beverly, BV, MP3, X8, X9, X10, X Evo, Gilera Nexus and Fuoco, Aprilia Atlantic and Scarabeo. Product code 840439.

✓ Strengths

• Original Piaggio spare part – official catalogue designation "transmission cover cap", code 840439
• Keeps out water and dirt – closes the casing inspection opening and protects the belt, rollers and clutch from dust, mud and water ingress
• One code for the entire 400-500 family – Piaggio, Gilera and Aprilia with the Master 400/500 engine
• Replaced in an instant – no casing disassembly required, reassembled by hand
• Costs very little, prevents expensive damage – working with the inspection open means water on the belt and premature wear

Technical specifications

Vehicle compatibility

Vehicle list from the official B2B Piaggio catalogue.

Who it's perfect for

This is the part needed when, after a transmission service, you realize that the inspection plug is missing or broken: this often happens because it's plastic and easily comes off when the casing is disassembled. It costs very little and prevents water and dirt from getting on the belt. It's also the right item for anyone restoring an older Beverly, MP3, or Nexus and wants to close everything up like the original.

Frequently asked questions

What exactly is the 840439 part?
The 840439 is the transmission cover cap: the plug that closes the inspection opening on the transmission casing. It serves to prevent water, dust and mud from entering the compartment where the belt, rollers and centrifugal clutch operate. This is the official designation in the Piaggio spare parts catalogue.

Does it fit both the Beverly and the MP3?
Yes. The 840439 is common to the entire family of Piaggio Group's 400 and 500 cc maxi-scooters: Beverly and BV 400/500, MP3 400 and 500 in all LT, RL, Sport, Business and MAXI versions, X8 400, X9 500, X Evo 400, X10 500, Gilera Nexus and Fuoco 500, Aprilia Atlantic and Scarabeo 400-500.

I found the same part with code 833319 or 841475: is it the same?
Yes, 833319, 841475 and AP8560224 are cross-references for the same item that appear in spare parts catalogues depending on the model and year. If your spare parts manual lists one of those codes, the 840439 is the correct part.

Do I need to disassemble the casing to replace it?
No. The cap closes an external inspection opening: it is replaced from the outside, without opening the transmission casing or touching the belt and rollers. It is one of the quickest spare parts to replace on these scooters.