Hi and welcome back!
When the transportation expenses are deducted using the standard mileage rate
- the accumulated depreciation
is calculated based on special rates
publication 463 - page 25
Rate of Depreciation Allowed in Standard Mileage Rate
Year(s) Depreciation Rate per Mile
So while that to be verified - I assume the truck is fully depreciated and its adjusted basis is zero.
So far - there are two options
- to report the disposition of the old track (the gain will be realized) as the sale and report the purchase of a new track for $23,000 + $19,000 = $42k
- use section 1031 exchange - in this case the gain will be partially recognized on the loan boot - $19k - and the rest will be deferred under section 1031.
In both cases section 179 deduction
for the new truck would be allowed up to the maximum $11,460 in 2014 prorated by the business use.