I am looking at buying a 1998 with the 24 valve Cummins. It is a 3/4 ton, 4X4, regular cab, and has almost 200,000 miles on it. During a test drive it had pretty good power and was running smooth, until i got up to 70 or 75 miles per hour. It then started shaking very hard. At first i thought maybe i lost power, but when i slowed down to 50 miles per hour the shaking stopped and it ran alright the rest of the test drive, although i didn't get going faster than 55. I then thought maybe the road was really bad at that spot, but when i took my Ford F-350 over it i found out it was fairly smooth. Got any ideas why this happened?

 

I have a 2000 4x4, bought new, and have not had any problems like you mentioned. The only time I notice any shake is a a rough road or a stretch where the road has heaved up during the winter.<br><br>The only other thing you might want to check are the tires. The sidewall could be starting to separate and you can feel small ripples on the sidewall. If this is the case you will need some new tires. I did have this problem on one of my other vehicles. Also, could be a balancing problem on the tires.<br><br>Mine runs right down the road at 80 mph on a smooth road without any problem!<br><br>Hope this helps, good luck!!!<br><br>smokinjoe<br>ohio<br><br>

 

With 200,000 miles and a 4x4, it's likely that the front end is loose unless the compontents like ball joints, tie rods, trac bar, and such have been replaced. Hard to tell from the description. Do you think it is engine related or suspension related? If it was engine related it should have more relation to RPM than MPH, i.e. it would shake at the same RPM in each gear. I would ask the seller if he has replaced any front end compontents or not.