I have a 92 ranger 3.0l v6 5-speed. When i start to take off in 1st or reverse My truck starts to shake a little. It defiantly aint fuel related because my whole entire fuel system has been redone. Im thinking the clutch or something to do with trans but im not a 100% sure. It happens after i release the clutch but once i get rolling it stops. It only happens if im at a dead stop. If i roll a little then release the clutch to get it in gear its fine. And it doesnt happen if i rev the engine a little and give it some gas before releasing the clutch. It only happens at low rpm's. This problem just recently occured after trying to push my buick with the ranger up a hill into my garage to work on it.

 

Check motor and transmission mounts

Block a tire, both sides
Open hood
Start engine and put in 1st gear
Slowly let out the clutch and watch engine
It will start to lift up on one side but motor mount on that side should hold it in place, so just a little movement
Push clutch pedal back down quickly and listen for a "clunk", thats a loose or broken mount mount
Now do the same test but use Reverse, opposite torque on engine

You have to get under the truck to check trans mount, see if you can push tailshaft around, shouldn't be able to

 

If its not engine mount then I'd suspect the clutch next.