Volvo Penta Throttle Body Stud 3858964

Volvo Penta OEM Throttle Body Stud Part No. 3858964

Compatible Applications

Volvo Penta used multiple throttle body configurations across similar gasoline engine families. Confirm the engine model, serial number, and throttle body diagram before ordering mounting hardware can vary by throttle body version, engine variant, and production break.

• Volvo Penta 4.3GL / 4.3Gi / 4.3GXi / 4.3OSi
• Volvo Penta 5.0GL / 5.0Gi / 5.0GXi / 5.0OSi
• Volvo Penta 5.7GL / 5.7Gi / 5.7GXi / 5.7OSi / 5.7OSXi
• Volvo Penta V6-200 / V6-225
• Volvo Penta V8-225 / V8-270 / V8-300 / V8-320
• Selected sterndrive and SX / DP-S / DPX packages with the above engines (verify by serial number)

When to Replace

Replace this stud if the original is corroded, bent, stripped, or damaged during removal from the throttle body assembly. It is also worth replacing whenever the surrounding throttle body is removed for service and the stud threads show wear a corroded stud discovered mid-repair is a common source of delays.

Installation Notes

Inspect the threaded bore and surrounding throttle body mounting surfaces before installing the new stud. Follow the Volvo Penta service procedure for the specific engine correct thread engagement and torque on throttle body hardware affects both sealing and retention of the assembly. Do not substitute generic hardware.

Technical FAQ

Is this a general-purpose stud or application-specific?
Application-specific. Volvo Penta 3858964 is cataloged at diagram position 23 in the throttle body assembly. Using a generic substitute risks incorrect dimensions and thread fit for the throttle body mounting point.

How many studs are required per assembly?
Confirm the quantity against the throttle body diagram for the specific engine Volvo Penta diagrams list the quantity per application. Order extras if the existing hardware shows corrosion, since stud damage often isnt apparent until removal.

Does fitment vary between Gi and GXi versions of the same engine?
Possibly. Volvo Penta used different throttle body designs across Gi, GXi, OSi, and OSXi production runs. Confirm 3858964 against the exact engine serial number and throttle body diagram before ordering.

Can I reuse the original stud if it looks intact?
If the threads are clean and undamaged and the stud torques correctly, reuse is generally acceptable. However, studs that have been in a marine environment for several seasons often have hidden corrosion at the thread roots replacing as part of a scheduled throttle body service is the lower-risk choice.

Parts Desk Insights

This stud most commonly comes up when a customer is ordering throttle body gaskets or sensors and discovers the existing stud is corroded or broken during disassembly. Its a low-cost item thats easy to add to a throttle body service order to avoid a mid-job delay. The wide engine family coverage means its worth confirming by diagram position (item 23) rather than just engine model, since similar studs appear in other assembly positions on these engines.