i have a 87 f-150 4x4 . its got the 302 and about 200 thousand and runs perfect. the tranny shifts a bit hard now and then but for the milage i cant complain. but my question is about the 4 wheel drive. it works fine but when turning on the streets or backing out of spaces in 4 wheel the truck kinda jumps. it almost feels like the tires are flat and its kinda hoppin. is this normal? i've had the truck 3 years and havent used the 4wheel much. also how fast can you go in 4 hi and low?

Sounds like you're using the 4WD on hard dry surface, which you should never do unless you have full time 4WD.

4wd plus hard surfaces equals a BIG no-no!!!!!

That jumping around is the front end/drivelines binding up and will most likely brake if you keep that up.

4wd should only be used on very slick surfaces, like mud, sand, ice, snow, etc. But never on dry, or even wet, pavement.

When in 4 wheel drive, never turn the wheel sharp, that will also cause your front end to bind up/jump.