the speedometer stops working on my 91 s10 blazer, when I get under the car and push it back in it works for a day then stops. After pulling the old speedo the rubber seal came out and was shot, I tried to find a replacement seal but they have been discontinued.The local chevy dealer gave me the diagram with the part # which is 00326563, the part # for the speedo itself is TX04-60. this speedo was used on some of 87-91 with the 4L60X (THM700-R4) transmissions. Does anyone know where I can get a replacement seal or a knew or compatible speedo. Thanks