I'm looking to buy a 06 megcab and while test driving it I couldn't help but notice that there was a vibration in the rear of the truck during takeoff. According to the owner, he did not notice the issue until he installed a 6" Tuff Country lift. From what I can tell without a tape, the rake on the truck seems much steeper in the rear that what my quad cab had. I am assuming that this vibration is caused by the drive line and perhaps incorrect angle. Any other ideas? Other than this the truck is great but I am leary about getting stuck with an expensive fix.

 

I'm not positive what the issue is but if you tell him you will buy it only after he fixes it I bet he'll do it. It's very hard to sell a truck these days.
Nothing worse than buying a vehicle and having to fix things right away.....

 

Could be the carrier bearing just needs to be shimmed. See if he put some shims in it with the lift and if he didn't that's probably the problem.

 

The "Takeoff Shutter" is a pretty well known issue, at least my 06' does it too. It seemed to go away if I carry any weight at all in the bed or if I was hooked to a trailer. From everything I have read in the past most think it is a driveline issue.

 

Do you think it is caused because the lift is too high? My 03 has a 6" lift with no problems at all but the Megacab is about 2" taller overall than my 03. Is this common?

 

The lift has something to do with it but it can most likely be fixed. The quad cab long beds and the mega cabs have a 2 piece rear driveshaft that requires a carrier bearing shim kit to be installed when the lift is over a set limit. Being a 6" lift, it definately needs to be shimmed. I would check and see if the shim kit has been installed. If not one needs to be. That is most likely the problem.

I don't understand why the mega cab is taller than yours if you guys have the same lift. Do both trucks have the same tire size? Is the mega a 3500 or 2500? Do both trucks have the three factory blocks above the lift-block in the rear?

 

I had the same issue from the start, but it got much worse after the lift. The key is to shim the carrier bearing like everyone is saying. It's super easy to do. I went to home depot in the electrical department and bought a bag of these square 1.5"x1.5" shims. Each one is about a 1/4" thick. They already have a hole drilled in the middle. I put three under each side after my lift and the take off shutter went away. I don't think they shim these trucks right from the factory in my opinion. It may take some playing around. 1/2" wasn't enough for me and had to go 3/4". The newer models (08's?) come with a one pc rear shaft. That's another fix, but obviously more expensive.

 

For every inch of lift in the rear you need approx 1/4 inch of shim between the steady bearing and the frame. You may need to have 1-1.5 inch of shim added.


Malcolm

 

Before considering the worst, check out exhaust vibration. I thought I may have had an issue on mine until I turned the mirror down and watched the exhaust tip on engine start up and take off - it was more pronounced after I straight piped - the rubber isolators on the OEM exhaust pipe are very soft - I can make my pipe move with one finger on the tip.

I can't explain it, but weight in the bed or pinned to a trailer makes it go away as well.

On take off, this is where I'm convinced my vibration is coming from, and it quits shortly thereafter.

 

Its called axel rap and mine started after the Fabtech 4.5 lift. I shimmed the carrier bearing and it helped but not completly gone. Fabtech is in the process with developing traction bars.