Ok so besides my 93 cherokee, my mother in law has a 93 cherokee also and she has been experiencing some strange problems, i think its the transmission but what exactly is wrong i dont know, when we are driving sometimes under the car around the tranny/column area it starts to rumble and shake real hard, only in that one spot the engine is fine, it picks up speed and accelerates fine, but it has this god awful rumbling in the tranny area any thoughts???

 

Does this occur at certain speeds, only on acceleration or deceleration? Is the rumble a result of the vibration or does it start before the vibs?

 

just throwing this out there but could be the tranny mount on the crossmember

 

during acceleration is when it occurs, and she just called me saying now it does it non stop when she has her foot on the accelerator, but the car is running fine so i dont understand completely

 

Check the trans mount as Clay stated, and check the u-joints on the driveshafts fronr and rear.

 

that makes perfect since, so when im under it tomorrow how do i check if its loose, and if thats the problem how serious is it

 

Tranny mounts are pretty serious being that they hold everything in line enought to make your powertrain work from front to back. But they are inexpensive and easy to change.

 

right on, but my mother in law just took it to a mechanic today and he is saying its the spark plugs and pcv valve, which makes no sence, those things are why it idles rough they wouldnt make the middle of the car jerk and vibrate that hard would they?

 

if your engine is misfiring so bad that it shakes and rumbles your check engine light would come on and then the computer would say that some cylinder was misfiring. But if it was a drive train shake or misalignment then it would probably be a bad u joint. You should take it to a good mechanic that knows what they are doing.