Question:
We had to replace a ballscrew last month but we still have some backlash. One of our customers, who repairs transmissions for heavy trucks and construction equipment, looked at the old thrust bearings and said they were still OK. These bearings are expensive so we don't want to replace them unless it is absolutely necessary. Our customer said he uses bearings like these that are bigger and cost a fraction of the price. Do we have to use the exact same bearings that the manufacturer recommends?

Answer:
Yes you do. You can use an equivalent but the accuracy and general specifications should be the same. It is a mistake to take advice from someone who is not involved with the product. Your customer may be an expert at what he does but he is unqualified to override a manufacturer's design. What works well in heavy equipment may not be suitable for a ball screw thrust, besides, if you spend good money on a new ballscrew why would you want to cut corners with the thrust bearings. Remember, a ball screw is only as good as the thrust bearings supporting it.