I have a 2015 Ram 1500 SLT. It's an 8' bed with a regular cab. It's the 3.6L gas 6 cylinder. The thing vibrates and feels just like a tire or wheel balance problem. Its got a brand new set of tires. A dealer tried to find the problem by switching all 4 wheels and tires from a new vehicle. No change. The vibration is most noticeable from 42-50 mph. They said the rear axle is ok and the driveshaft is ok. They checked their "forums" and said others have reported this problem and they don't know what it is. I'm tired of putting up with it and was considering replacing u-joints just to try something. Here's my question: It has a 2-piece driveshaft and I don't know whether to change all of the u-joints, just the end ones or just the middle ones. Has anyone had similar experience and/or any luck in changing u-joints to fix a vibration problem. Thank you.
Wow!!! That dealership scares me. As a former Ford and GM Tech, I do know that one ESSENTIAL tool required by the manufacturers across the board is (among many) an electronic NVH (noise, vibration, harshness) analyzer. This piece of sophisticated electronic equipment takes out the "try swapping parts" aspect, and accurately points a competent tech to the problem; thus a fix.
Question is, does that dealer have a competent tech who KNOWS not only how to use one of these tools, but, MOST importantly, WILL said tech do so?
Years ago, I had a fellow tech bring me a new, under warranty Mustang with a very similar vibration as you describe.
After he had replaced the harmonic balancer, motor mounts, driveshaft, realigned the exhaust, and replaced the wheels and tires (temporarily) from a new car in stock, he brought it to me (I was an automatic transmission specialist) for my insight.
I asked him if he had used the NVH diagnostic tool, to which he replied that he didn't know what that was/is. After a lengthy search for ours, I found it on an upper purloin of the shop building, over by the front end department. The original color of the blow molded case was red, but this one was coated in an oily, nasty black concoction of oil film and gritty filth.
I cleaned it off, and showed him how to use the tool. The problem turned out to be a bad torque converter. Go figure.
I'm a one-man shop today and am semi-retired (IOW, I work when I want, and take naps when I want! LOL) and I own one of these very critical tools (mine is a Pico and complements my Pico oscilloscope). It is crucial to have one to prevent spending so much valuable time and money on high dollar parts. Shot-gun repairs are so unprofessional and expensive.
In closing, you might consider finding a competent tech who is savvy about use of modern diagnostic equipment, regardless of where he or she is employed. It's the best bang for your buck given the sophistication of today's vehicles! I hope this helps you! Good luck!