CT55902 - A new front pump seal and rear seal for Turbo Hydramatic 400 transmission 1964-up. This kit includes the less common smaller rear seal in TH400 transmissions. The front pump seal fits all models of the TH400. The rear seal has an OD of approx. 2.50 inches.. It is typically in Th400 Tail Housings that have the number 8623214 on the tail housing. Please compare to your existing seal as rear seal sizes will vary on the TH400. This is known as the small rear seal. The front pump seal measures 2.765 to 2.770 inches. New and unused. Made in USA.