Well, I will say that although the new Honda MTF is good (never experienced old stuff that I know of), it can increase the effort of going into 3rd, 4th, 5th, at least on my transmission. Some would call that, becoming notchy. It wasn't bad, and 1st and 2nd were better than w/ engine oil on my trans. but it's known to increase the notchiness on older transmissions.
I'm now running Mobil1 0w30 and it goes in much easier for 3rd-5th and also reverse, with no noticeable difference (yet) for 1st and 2nd from the Honda fluid.
The new Honda fluid, good as it is, just seems a bit thin for 1) tolerances of older trannies and 2) the bearings of those older trannies that now have at least some appreciable wear.


I've not done this (at least not yet) but just a thought, that if things don't improve w/ your 3rd gear engagement, you could try letting about 1/2 of the fluid out, and adding a quart of motor oil to thicken it up as well as (maybe) decrease the friction a bit - sounds counterintuitive for how the synchros work, but it seems to work on some of the older transmissions :shrug: It's just that it's pretty much like water, but leaving 1/2 in there would be good for several reasons, including the zinc that is has in it, so that would still be in there helping synchros, whatever. That's if it doesn't improve, if you just replaced the fluid, I'm sure the problem will improve some.