Jeep 1993 grand cherokee shakes when I excel over

Fix your car right away, by clicking the link
1993 Jeep Grand Cherokee Service Repair Factory Manual INSTANT DOWNLOAD

Did you try a good set of plugs and wires?

Usually a bad crank sensor or a bad ecu computer.

Locate a dirt parking lot or field and engage the 4wd. Make a slow tight turn and you should feel some resistance while turning as the wheels dig in and fight one another causing the steering wheel to shake somewhat too. Do not attempt this on pavement or damage may occur. If you can turn freey and not notice any difference then when your in 2wd its likely not working.

Whether you have a drive shaft on or not the roll back is the ebrake not properly working like it should it will need a adjustment,and as for the bouncing speedometer you will need to inspect the cable as they can wear out.

check speedometer cable and speed sensor

This is not an auto shift or slap stick it is actually used to determine your top gear... its like putting your care in 1 or 2 gear

No, not with out a lot of work. Electronics are most likely different on the 2 also.

check the vaccume module on the front axel it my have come un pluged or the electric connector hope this helps

You did not say if you checked the fuses.