Si la roue avant fait encore du bruit demain, nous demanderons de l’aide avant de reprendre la route vers le sud.

This is the normal pattern for a real future condition in French:

• Si + present tense, then
• future tense in the main clause

So:

• Si la roue avant fait encore du bruit demain = If the front wheel is still making noise tomorrow
• nous demanderons de l’aide = we will ask for help

French does not normally use the future tense right after si in this kind of sentence. So Si ... fera would be wrong here.

A useful pattern to remember:

• Si j’ai le temps, je viendrai. = If I have time, I’ll come.
• Si tu peux, appelle-moi. = If you can, call me.

Faire du bruit is a very common French expression meaning to make noise or to be noisy.

Literally:

• faire = to do / to make
• du bruit = noise

So la roue avant fait du bruit means the front wheel is making noise.

French often prefers this expression instead of a single verb. It is idiomatic, so it is best learned as a chunk:

• faire du bruit = make noise
• ne pas faire de bruit = not make noise / be quiet

In French, abstract or uncountable things often need an article where English does not. Here, du is the partitive article, often used for something seen as an unspecified amount.

So:

• faire du bruit = to make noise
• literally, something like to make some noise

You usually do not say faire bruit in standard French.

Compare:

• Il fait du bruit. = He is making noise.
• Il ne fait pas de bruit. = He isn’t making noise.

Notice that in the negative, du becomes de.

Here, encore means still.

So:

• fait encore du bruit demain = is still making noise tomorrow

Encore can have a few meanings depending on context:

• still / yet: Il dort encore. = He’s still asleep.
• again / another time: Dis-le encore. = Say it again.

In this sentence, still is the natural meaning.

In French, avant can be used after a noun to mean front.

So:

• la roue avant = the front wheel
• la porte avant = the front door in some contexts, though porte d’entrée is often more natural depending on meaning

French often places this kind of descriptive word after the noun, where English puts it before.

You may also see:

• la roue arrière = the rear wheel

So avant and arrière are very common in vehicle-related vocabulary.

The verb demander often takes de before the thing being requested in expressions like this:

• demander de l’aide = to ask for help
• demander de l’argent = to ask for money

Here:

• de l’aide = help / literally some help

The apostrophe appears because aide starts with a vowel:

• de + l’aide = de l’aide

Also note that aide is a noun here, not a verb.

Compare:

• demander de l’aide = ask for help
• aider quelqu’un = help someone

So French is using ask for help, not help as a verb.

After avant, if the subject of both actions is the same, French normally uses:

• avant de + infinitive

That is exactly what happens here:

• nous demanderons de l’aide
• avant de reprendre la route

The people who will ask for help are the same people who will resume the trip, so the infinitive is used.

If the subject changes, French often uses avant que + subjunctive:

• Nous partirons avant qu’il n’arrive. = We will leave before he arrives.

But here, the subject stays the same, so avant de reprendre is the natural structure.

Yes, but it is also a common expression.

• reprendre = to take again / resume
• la route = the road

So reprendre la route means to get back on the road, to continue the journey, or to set off again.

It is very idiomatic and common when talking about travel.

Examples:

• Après le déjeuner, nous reprendrons la route. = After lunch, we’ll get back on the road.
• Ils ont repris la route tôt ce matin. = They got back on the road early this morning.

Vers means toward or in the direction of.

So:

• vers le sud = toward the south / southward

This fits well with movement: they are continuing their route in the direction of the south.

By contrast, au sud usually refers more to location:

• Ils vivent au sud de la ville. = They live in the south of the city / south of the city.

So here:

• reprendre la route vers le sud = get back on the road heading south

Demanderons is the simple future of demander for nous:

• je demanderai
• tu demanderas
• il/elle demandera
• nous demanderons
• vous demanderez
• ils/elles demanderont

It means we will ask.

In pronunciation, the ending -ons is pronounced, and the full form sounds approximately like:

• nous demanderons ≈ noo duh-mon-duh-RON

Very roughly, the stress naturally falls toward the end, as is common in French rhythm.

Yes, it could move, but its current position is very natural.

Here:

• Si la roue avant fait encore du bruit demain
  means
• If the front wheel is still making noise tomorrow

Placing demain at the end of the si clause clearly connects tomorrow with the condition.

You could also say:

• Demain, si la roue avant fait encore du bruit, nous demanderons de l’aide...

That would put more emphasis on tomorrow as the time frame for the whole sentence.

So the meaning stays close, but the focus shifts slightly depending on placement.