Tom was professional, knowledgeable, and very friendly. He arrived at my house within the time frame he said he would (nothing is worse than a late technician). Once he arrived, he assessed the problem, explained it clearly and concisely, and informed me he had the parts available with him to fix it. He fixed the issues speedily and I was able to return to work within the hour. The price was reasonable too. I would recommend Precision to any of my friends and neighbors. Thanks Tom!
Having a mismatched pair makes it difficult to specify the correct matched-pair replacements. To obtain replacement springs for a mismatched pair, you can either specify the same odd pair, try to calculate the equivalent matched pair sizes, or (this is the best method:) measure an accurate door weight and calculate the right spring size(s) "from scratch". The spring seller should be able to do the calculations from your accurate measurements of weight, height, and drum size; or you can attempt the calculations yourself using my engineering formulas below.