Is it necessary to have a timing belt replacement at 105,000 miles, or can I wait another 1000 miles, after a rather long road trip in California? It can’t be done in time for this trip.
You’re going 1% over the recommended mileage, so the risk is pretty small.
However, how old is your car? Many people ignore the elapsed time part of the maintenance schedule (for some reason that I can’t fathom).
Most likely yes. The belt doesn’t automatically self-destruct at 105K miles, and many folks have gone past without any negative repercussions. There is a risk it may break on your trip, however.
There was also the risk that it could have broken at 80 or 90K miles. I’d probably go for the trip, but then that’s me. A friend’s 2.5L Legacy wagon had the belt replaced at 109K. That was done by a Soob dealer. Then it slipped a cog on one side at 135K. Luckily the pistons did not kiss the valves, although it is an interference engine.
We can’t tell you when exactly it will self destruct. A belt may go out as you drive out of the dealers lot the day you bought it new. Every mile/day is one mile closer to the end. Chances are you will be fine. However putting it off at this time starts increasing the chances of serious damage.
I would make an appointment now for when you get back.
No worries, enjoy your trip 