Q: How to replace the extension housing oil seal in Chevrolet Colorado and GMC Canyon?
A: Oil leaks frequently occur due to wear of the extension housing oil seal, but fortunately, replacing this seal is relatively easy and can be done without removing the transmission from the vehicle. The extension housing oil seal is located at the rear of the transmission where the driveshaft is attached. If there is leakage at the seal, raise the vehicle should and support it securely on jackstands. If the seal is indeed leaking, transmission lubricant will be built up on the front of the driveshaft and may be dripping from the rear of the transmission.