Trannie troubles ( not the kind you are thinkin of perv.)

I am experiencing some issues with my 98 ford ranger. it is a 3.ol v6 XLT with a 5 speed transmission.

When I drive it I am okay with shifting until I get about a mile up the road and then it becomes difficult to shift and eventually will lock up. I f I let it sit and cool it will go about another 1.5 until it locks up again.

I think the problem is either with the Master cylinder or slave cylinder for the hydraulic clutch. Any opinions

When you say ‘lock up’ do you mean that the rear wheels stop turning and skid to a stop or do you mean that you cannot get into any gear without forcing the shifter? Maybe a better term might be ‘lock out’ as in locked out of gears. A more specific description of ‘lock up’ will helps us zero in on the problem.

My practical experience shows these transmissions (and many others) can be shifted without using the clutch,so Iam not on-board with the clutch hydraulic system causing this concern.Does the gear oil smell burnt?Is the trans any louder than when new?