Filthammeren og demperen kontrolleres sammen.

Because Norwegian usually puts the definite article on the end of the noun instead of using a separate word like the.

So:

• filthammer → filthammeren
• demper → demperen

That -en ending is the definite singular ending here, so these forms mean the filthammer and the damper.

Kontrolleres is the present passive form of å kontrollere.

Compare:

• kontrollerer = checks / is checking
• kontrolleres = is checked / are checked

So the sentence uses the passive voice: the parts are receiving the action, not doing it.

Norwegian often makes the passive by adding -s to the verb, especially in formal, technical, or instructional language.

So:

• kontrollerer → active
• kontrolleres → passive

This -s passive is very common in manuals, procedures, and descriptions because it sounds concise and impersonal.

Yes. Filthammeren og demperen blir kontrollert sammen is also correct.

Both are passive, but they have slightly different style:

• kontrolleres = shorter, more compact, often more formal/technical
• blir kontrollert = also common, sometimes a bit more explicit or neutral in everyday language

In a manual or technical description, kontrolleres is very natural.

Because Norwegian verbs do not change form for singular vs. plural subjects.

So the same verb form is used whether the subject is one thing or more than one:

• Demperen kontrolleres
• Filthammeren og demperen kontrolleres

Unlike English, Norwegian does not need a special plural verb form here.

That is a very normal place for an adverb like sammen in a sentence like this.

The structure is:

• subject: Filthammeren og demperen
• verb: kontrolleres
• adverb: sammen

Putting sammen at the end gives a neutral meaning: the two items are checked together.

You can move it for emphasis, but that sounds more marked, for example:

• Sammen kontrolleres filthammeren og demperen

The original sentence is the most straightforward version.

This is normal Norwegian main-clause word order: the finite verb comes early in the sentence, in the usual verb-second pattern.

Here the first element is the subject:

• Filthammeren og demperen = first element
• kontrolleres = finite verb
• sammen = adverb

So the sentence is built in a very standard Norwegian way.

Yes, that is possible in some contexts, but the meaning and feel are slightly different.

• Filthammeren og demperen points to specific, known parts
• Filthammer og demper sounds more generic, like talking about those components as types or labels

In technical writing, the definite form often means the specific parts being discussed in this machine/system. That is why the sentence sounds natural with -en on both nouns.

It is very natural Norwegian, especially in written technical language.

It sounds like:

• a manual
• a maintenance instruction
• a procedure description
• a technical report

In casual speech, a speaker might choose a less compact passive form, but this exact sentence is perfectly normal in formal or technical contexts.