i have a 91 f250 5.8l and once is gets up to speed and warmed up it shakes violently. any ideas what could be wrong? also my check engine light has been on constantly since i replaced the front u joint and tie rod. any suggestions?

 

I suggest you check codes.

 

could be tires, front end alignment, suspension components, etc.

 

Alright. I drove it some more and it seems that the worse is between 30-45 mph when I'm not on the gas too hard

 

Could be anything.. Rear drive shaft u joints, loose lug nuts, out of balance tires. You gotta start looking for loose/worn parts

 

I wouldn't think worn suspension parts would only show symptoms after it warms up. I would be looking at the ignition and fuel system first... especially since your cel is on. Pull codes and go from there. Sounds like a bad miss, the way you describe it.

 

I am an operations manager for my company and we have 22 vans. we have a similar symptom from time to time. Vans will be fine till you get to a range usually around 45-55, 40-50, 50-60, or something similar. At that point they start shaking, but if you ease off the gas and then go back through the range it is fine. If you keep going through the range, without backing off, then it gets worse. Every time it is either the tires (balance or wear pattern), alignment or joints. Those are a great place to start.

 

I'm going to take it to a garage here soon.. I need to get it inspected anyways... but I'll have them align the drive shaft and wheels. Is there anything else I should get aligned?

 

If you have shaking and it's suspension related, I doubt aligning anything will help. They probably will be able to tell you what needs replaced, though.

 

Maybe you over looked Sean's post? Did you check codes?