1990 4runner,3.0,auto,177,000 mi,stock,33's , no cat....bumped bottom after coming off a trail the other day, not very hard , no visible damage, got on the highway and noticed a vibration that I thought may have been my tires, ran rugged after that, changed plugs,wires,cap,rotor,fuel+air filter, oil is good, tran fluid good, took her for a run , ran better than ever, fired her up this AM, runs worse than before, shaking , stuttering, no power,never had a problem with her before, slight vibe coming from underneath,tranny, transfer,? don't see anything, only acts like this under load, is there any kind of sensor I could have knocked loose? Thanks for all the knowledge available on this site, sometimes overwhelming.

 

U joint on drive shaft, had the same thing happen to me, does it do it worse around 60 to 65 mph

 

What speed it shakes at depends on the damage. Some will only shake at 10kmph and some will only shake at 130kmph.

You could have also bent a driveshaft when it was dropped. An easy way to check is to take out either drive shaft, then go for a quick drive and see if the shake still there. That will confirm the balance of your drive shafts.

To quickly check your u-joints, get underneath and grab your drive shaft right beside the u-joint. shake it like you havn't seen your girlfriend in 3 months. If theres any play in the u-joint...change it.

Or suspension parts may have been bent, messing up your alignment and causing a shake.

As for the rough running, We need a better description on whats happening and when it happens if we are going to do anything besides throw out random advice in hope it works.

 

If its worse under load, that may indicate an ignition part breaking down, i.e. plug wire, plug, dist cap or rotor. And that could be causing bad vibration which would make stuff rattle around. Just a thought...

 

Yep, was the u-joint, found out after, full tune including NGK wires and plugs, she runs super sweet, had never been touched before, I even think the MPG came up by 1 mi..