Can anyone please check my work for the adjusting entries for depreciation?


Truck was acquited on 7/1/98 for $162,000. 6 yrs useful life, salvage value $18,000, Straight-line method. On 1/1/01 truck was overhauled for $15,000 which extended the useful life to 6 yrs. In calculating depreciation expense is calculated on a monthly basis. Prepare adjustment entries for January 1, 2001 and December 31, 2001.


My calculations are:
162,000 - 60,000 (A/D) + 15,000 = 117,000 (book value) - 18,000 = 99,000 (adjusted cost to depreciate) / 66 months remaining to depreciate = 18,000/year


12/31/01 Dr Depreciation expense 18,000

Cr Accumulated Depreciation 18,000


I am not sure what entry to record for 01/01/01... Please help!!!