Campers with gross mass over 3.5 tons

Things change and looks as if this is just another one - like RHD vehicles in two countries in Central America which used to allow RHD under certain conditions but which since a couple of months ago have banned them completely.
The Mexico truck/camper ban is also quite recent - maybe only 6 months old. One recent traveller with no choice but to keep going north was forced to pay for an escort vehicle right through Mexico. Must be only a matter of time before this rule is applies to all those truck campers crossing the north border as well and since it looks like they are using the gross vehicle weight printed on the vehicle documentation, the weight of the camper is irrelevant.

So are these vehicles traveling north? Your post says southern Mexico refusing entry. I have never heard of any problems and have met quite a few large truck-campers heading further south and followed numerous blogs with no problems.
I have however, heard and met people with problems with right-hand-drive vehicles not being admitted south of Mexico.

So are these vehicles traveling north? Your post says southern Mexico refusing entry. I have never heard of any problems and have met quite a few large truck/campers heading south and followed numerous blogs with no problems.

I met a couple this year that were charged 8000 pesos to bring their truck camper into Mexico. I checked the documents which were official. I also went to the permits department in Reynosa and talked to the officials. Apparently, their was a discussion between the person from SAT (Banjercito) and the person issuing the permits. The SAT official insisted that if there wasn't a temporary permit issued, they would be charged an import tax. The person issuing permits said that a permit wasn't required for a truck camper so the tax was charged.

Looks like people need to watch their weight and that there is a change in the temporary importation rules.