A truck was acquired on July 1, 2012, at a cost of $162,000. The truck had a six-year useful life and an estimated salvage value of $18,000. The straight-line method of depreciation was used. On January 1, 2015, the truck was overhauled at a cost of $15,000, which extended the useful life of the truck for an additional two years beyond that originally estimated (salvage value is still estimated at $18,000). In computing depreciation for annual adjustment purposes, expense is calculated for each month the asset is owned. Prepare the appropriate entries for January 1, 2015 and December 31, 2015.