I reached out to Sailun's distributor in the USA (TBC). I asked them if they knew about the problems with recent Vietnam produced tires and what options do I have to ensure that I will not have similar issues? I also asked if they can still source 637 trailer series tires that were made in China? (see their response below).
Sadly, I finally convinced my brother to buy Sailuns and his are made in Vietnam with similar date codes to those reported to have failed. I've had great luck with my 2 year old chinese made Sailuns, but will likely not replace them in the future with Sailuns made in Vietnam.
Dear Mr. XXXXX
As previously indicated, we reached out to Sailun with your inquiry. Sailun has indicated that all their specialty trailer tires are fully tested to conform to the U.S. DOT requirements. Uniformity, x-ray, shearography, physical and visual inspections are all part of the quality process at all factories to ensure a quality product is released to the customers.
Should a customer encounter any tire failure with any of the Sailun products, it is always recommended that a full inspection is conducted by a qualified technician, at the place of purchase (if possible), to ensure no damage occurred to the remaining tires before the disabled tire was replaced.
Sailun offers one of the leading Manufacturer’s Warranties in the industry. If a tire that fails due to a defect in workmanship and/or materials within the first 50% of the tread of the tire, will be replaced at no cost; after the first 50% of the tread of the tire, a pro-rated adjustment will be offered. This warranty is for eight (8) years from the date of purchase or down to 2/32nds of tread remaining, whichever happens first. Sailun also offers support in the event that the equipment experiences damage due to Sailun tires.
The most important factors in maintaining the performance reliability of any tire are proper application, air pressure, and frequent inspection. We appreciate your support and interest in the Sailun S637T.
Tel. (800) 238-6469
Fax (800) 467-4638