Transmission wont hold 1st

[Denver Ranger]

I have a 2000 ranger xlt 4x4 3.0l auto tranny 4 speed.
Today I finally got it up into the hills to try the 4 wheel drive, unfortunately I found out that when I try to manually put the tranny into 1st gear it does not engage. In other words ,I have no engine braking at all, it just rolls like I am in netural. Back on the highway, all other manual downshifts seem to work fine, just not first.
Any help would be appreciated,
Charles

 

[Jspafford]

There were a few threads on the old boards about this. Both the ranger's I have had did the same thing, no engine braking in 1st, second works, but not 1st, one of mine was a 5R55E and one is a 4R44E, had a friend with and explorer and his didn't do it either.

No one can tell me why.