Vi finner understellsnummeret uten at vi flytter reservehjulet.

Because -et is the definite ending for many Norwegian neuter nouns.

• et understellsnummer = a chassis number / the vehicle identification number
• understellsnummeret = the chassis number

Norwegian often attaches the to the end of the noun instead of using a separate word like English does.

Also, understellsnummer is a compound noun:

• understell = undercarriage / chassis
• nummer = number

So the whole word means something like chassis number.

For the same reason: it is the definite form.

• et reservehjul = a spare wheel / a spare tire
• reservehjulet = the spare wheel / the spare tire

Again, Norwegian puts the definite article on the noun itself.

This sentence is talking about a specific spare wheel and a specific chassis number, so the definite forms are natural.

Because this is a normal main clause statement.

In Norwegian main clauses, the usual pattern is:

subject + verb + rest

So:

• Vi = subject
• finner = verb

That gives:

Vi finner understellsnummeret ...

If you said Finner vi ..., it would sound like a question or would require a different structure or context.

Examples:

• Vi finner understellsnummeret. = We find the chassis number.
• Finner vi understellsnummeret? = Do we find the chassis number?

They are both in the present tense.

• finner = find / are finding
• flytter = move / are moving

In Norwegian, the present tense is often used in ways that English might translate as either:

• a general statement: we find
• an instruction/demo context: we can find / we find
• an action happening now: we are finding

So the exact English translation depends on context.

Uten at means without (something happening / without the fact that...).

It introduces a subordinate clause with its own subject and verb:

• uten at vi flytter reservehjulet
• literally: without that we move the spare wheel

In more natural English, that becomes:

• without moving the spare wheel
• or without us moving the spare wheel

This structure is common when Norwegian wants to say that one action happens without another action taking place.

Yes, very often it could.

• uten at vi flytter reservehjulet
• uten å flytte reservehjulet

Both can mean without moving the spare wheel.

The difference is mainly grammatical and stylistic:

• uten å + infinitive is often the more direct and compact way to say without doing something
• uten at + clause is useful when you want to include or emphasize the subject, or when the clause is more complex

So:

• Vi finner understellsnummeret uten å flytte reservehjulet.
• Vi finner understellsnummeret uten at vi flytter reservehjulet.

Both are natural, though the uten å version may feel slightly simpler.

Because after at, Norwegian uses subordinate clause word order.

That means the subject usually comes before the verb:

• at vi flytter
• not at flytter vi

So the pattern is:

uten at + subject + verb + rest

Examples:

• uten at vi flytter reservehjulet
• uten at han ser det
• uten at de vet hvorfor

This is an important contrast with main clauses, where Norwegian often has verb-second word order.

Because the sentence refers to specific, identifiable things.

• understellsnummeret = the particular chassis number for the vehicle
• reservehjulet = the particular spare wheel in the vehicle

In instructions, manuals, and practical descriptions, Norwegian often uses the definite form when the object is understood from the situation.

Using the indefinite forms would sound more like:

• a chassis number
• a spare wheel

That would be less natural here, because we are not talking about just any number or any wheel.

Usually, yes, in practical use it often refers to the vehicle’s VIN or chassis number.

Depending on context, Norwegian may also use terms like:

• VIN-nummer
• chassisnummer
• understellsnummer

In many real-life situations, these are used more or less interchangeably, though exact usage can vary by country, institution, or type of vehicle documentation.

In this sentence, vi has to be there in the second clause because uten at introduces a full clause, and a full clause normally needs its own subject.

So:

• uten at vi flytter reservehjulet = correct

If you want to avoid repeating vi, Norwegian usually switches to the infinitive structure:

• uten å flytte reservehjulet

That is one reason the uten å version is often preferred: it is shorter and avoids repeating the subject.

Yes. Norwegian very often writes compound nouns as one word.

So:

• understell + nummer → understellsnummer
• reserve + hjul → reservehjul

Then the definite ending is added to the whole compound:

• understellsnummeret
• reservehjulet

English often writes these as separate words, but Norwegian usually does not. This is something English speakers often have to get used to.