Joy
I haven't changed an axle on a TT, but I have built a homemade utility trailer
and axle placement is critical to weight distribution and handling. I'm not
sure if an inch will make much difference but I'm sure you will want to get it
as close to perfect as possible, but of course you strive for perfection.
In my case with the utility trailer I was off several inches and at high
speeds it would get a little squirrelly.
I thought it wasn't exactly straight or my load wasn't balanced well enough. I
called a local place that builds trailers and asked them and they said that
they use a chart with axle positions already calculated according to the
length of the trailer. I told them the length of mine and they gave me the
measurement I needed for proper placement. With the info they provided I
repositioned my axle a few inches and the trailer tows great now, even at
interstate speeds load or no load.
Maybe you can contact one and ask about the position and see what tolerance
plus/minus would be suitable for your application. I bet Dexter may even have
that info. May be a question worth asking.
Take care
Bobby