Differential whine on my Wrangler, is this place actually legit?

[dominictoretto]

My Wrangler has developed this annoying whine from the rear end that gets louder the faster I go, and I'm pretty sure it's the differential starting to go. I've been putting off dealing with it because every garage I call gives me a different story and I don't want to get taken for a ride on a rebuild I might not even need. Someone in a Facebook group dropped https://zenfoautoservices.ae/jeep-repair-abu-dhabi/ and said they had a decent experience there, but I don't know the guy and I'm skeptical of random links. Has anyone here actually used them for diff work or heard anything? I'm mainly worried about them just replacing the whole unit instead of diagnosing the actual cause, because that's what happened to a mate of mine at another shop. Also curious if they let you see the old parts afterwards or if that's asking too much. Would appreciate any honest feedback because I'd rather not gamble on this.