I have a 1990 Ford ranger 2.3l that doesn't seem to like 1st gear. To put the truck in first with the clutch to the floor I have to kind of wiggle it in to first and it goes it somewhat hard. The other 4 gears seem to be easy to go into, and going into 4th and 5th it slides in the easiest...

 

I'm no expert but it sounds like a bad slave cylinder

 

The shifter on these trucks are known to benefit from getting rebuilt.

The kits are super cheap and easy to install.

My truck was very hard to get into first and few other gears now it is around 93 % better

If your transmission fluid is old changing it could smooth things out as well.

Do not mess with the clutch unless it is absolutely nessasary.

There are many other suggestions and test you can perform to diagnose the problem.

But the very first step I would take is to rebuild the shifter.

Search this and other Ford Ranger forums or YouTube and you will see how easily it is to rebuild the shifter.

The kit is less than 20 bucks normally

 

I just replaced the trans oil and it didn't seem to make much of a difference. I'll look into the shifter though.

 

Did you install a used transmission? Using the original shifter or one that came with the transmission.

 

I believe it is still the original trans in the truck. As it sits it has 64,000 original miles.

 

Sorry I do not get much sleep any more because of my back, I thought you said you replaced the transmission.