My 2006 mega cab 4x4 (3500 SRW) has developed a strange vibration over the last year or so. Ive searched numerous threads that discuss this issue and many owners have described it very similarly to my issue, but no one has posted a solution.

Basically it is a vibration that starts around 65 MPH and gets progressively worse as speed increases. Around 70 MPH it becomes a vibration the comes in 1 second "waves". It vibrates-stops-vibrates-stops at about 1 second intervals.

Truck is very low miles at 50,000 original miles. I am the original owner and this truck is almost 100% stock with 2 exceptions: 1 piece aluminum driveshaft and 285/70/17 Bridgestone tires. Never had a tuner on it at all and has never been off-road or abused in any way.

Vibration is speed related but it is worse if under power, as opposed to when coasting.

Things done to troubleshoot:

1. Changed tires. The originals were dry rotting so put on new Bridgestone tires 1 size bigger than stock.
2. Changed out 2 piece rear driveshaft. When this vibration first started my first thought was u joints or center bearing-Great excuse to upgrade to a 1 piece aluminum driveshaft. Had one built by a local shop with new u joints.
3. Removed front driveshaft.
4. Rebuilt transfer case with a bearing and seal kit. Never replaced the chain because it was still in good shape. All internals looked in fine.

My next thought was maybe the engine/transfercase mount is getting weak, but I don't want to just throw any more parts at it.

Any other suggestions?

 

Sorry I can't help you but I have the exact same truck and the exact same vibration. I was just about to pull the trigger on a one piece drive shaft but am glad I haven't yet after reading it didn't help you. I bought the truck 9 years ago with 54,000 miles. I don't remember it vibrating at first but I put new tires on it a few months later and soon noticed the vibration. I put 285s on as well. I now have 160,000 miles on it and have learned to ignore it. It does bother me when I notice it but I can't afford to replace the truck with the price of new ones so I just live with it. On a brighter side it seems as if the vibration reduces if I drive if longer than an hour or two.

 

You weren't kidding when you said it is the exact same truck...Patriot blue Laramie mega cab. Even the color is the same.

I drive my truck so infrequently that I haven't really been able to get a good handle on how consistent it is and troubleshooting the problem.

However the last few weeks I have used it as a daily driver and the vibration is very inconsistent when it comes and goes. Some days it starts at 62 MPH like clockwork, but the other day it would only do it at about 70MPH. Sometimes it gets worse with speed, and others it stops just after 70 MPH.

There is a lot of discussion threads about this type of problem back when the 3rd generation trucks came out, but no one ever posted a solution to the problem.

The way this issue changes makes me wonder if I have a weak motor or transfer case mount. If the vibration was due to an "imbalance" on something rotating, it wouldn't change from day to day.

How long has your truck had the problem?

 

I bought it with 54000 9 years ago. It started shortly thereafter.

 

I had a similar problem with mine. I bought it about 2 years ago with 160K on the clock. I had front and rear driveshafts rebuilt, tires spin balanced with weights, idler pulley replaced (thought on the off chance that the vibration was the belt harmonically vibrating at high speed). 3 weeks ago I bought new tires, 35x12.5x20 and had them install balancing beads. I no longer have the vibration at 62-68 mph. I do not know if it was one the old tires just being slightly out of round or if it was out of balance.

Gary

 

Had a set of tires installed on my vw bug, at discount tire, they just throw the tire on and balance, having worked in the aviation industry, learned the red dot on the side wall goes aligned with the valve core. Original balance tire vibrated and shook the whole car, returned to discount tire and had them align red dot with valve stem, balanced tires, now up thru 75 mph "down hill" positively no tire vibration at all, so check the red dot alignment and valve stem, balance and road test, hope your vibration is gone. u can google tire red dot.

 

I get my truck tires now at the local independent Dodge shop as I don't trust my local Discount to balance and mount them. i have used them for our Honda Pilot with good luck.