Info on Pamir Highway in Tajikistan

[BuddyGlass]

Hi everyone!

I'm posting here this question even if it isn't strictly motorcycle-related... Hope you can help me anyway.
I'm planning a trip on the Pamir Highway from Osh to Dushanbe this August with a few friends in my car (small 4x4 but, alas, quite old). It wouldn't be a proper "tour" of the area, but part of a much bigger itinerary so it shouldn't take more than the needed 2 or 3 days (of course we'd be taking care of the visas and the special permit for the GBAO area before leaving in the first place).
If some of you more experienced guys could help us understand if we're up to the task, that'd be much appreciated… We've already travelled all around Turkey and Armenia, but this'd be a whole new experience.

Basically, we don't speak russian, tajik nor kyrgyz… is there any way we can communicate with locals, namely local mechanics or roadside assistance in case of emergency (which could mean technical issues with the car, so that's quite tougher to explain than basic needs)? Is there a tow truck service operating on the road and do you know how much it could cost? We'll travel on a tight budget, but being stranded up there is something we'd like to avoid.
Our main concern is communication regarding the mechanical stuff: is it hard to have a car inspected (for instance in Osh) before leaving for the "wilderness"? An inspection might be necessary 'cause our car will already have something like 10.000 km on its back since the beginning of the trip.
In short, I haven't got much faith in my car.
So the other option would be leaving the car in Dushanbe and renting a 4WD to drive at least to Karakul lake and back, possibly without a driver. Do you know if there are any agencies in Dushanbe that provide this kind of service (and an approximate idea of the price)?

That's pretty much it.
Your help, any kind of help, would be immensely appreciated.

Thanks!