We do not accept unauthorized returns. Please e-mail, or call us regarding any problems with an order for assistance or return authorization number. Returned parts must be unused, in original condition, and in original packaging and received by Diffsonline LLC no later than 30 days after sale for a refund. No return will be accepted without a return authorization number. No returns are allowed on custom built products, including but not limited to differentials, and any custom fabrication. Returned items are thoroughly inspected before a refund is issued. There is no refund on special order items. A 20% restocking fee will be charged to all returns not due to our error. There is no refund for any shipping charge on returned items.