Shudder when accelerating from a stop.

I have an '07 V6 TRD-OR 4X4 double cab and the last week or so it has developed a light but noticeable shudder when accelerating from a stop. Hard to pin down the exact conditions, but it seems to happen around 1500 RPM at around 20 MPH. At first I thought it felt better when in 4WD, but it feels the same in both 4 and 2WD. From what I can tell I still get plenty of power, and everything seems to run fine at higher speeds. Just wondering if anyone has had a similar experience and has any ideas.

 

Have your drive shaft u-joints thoroughly lubed. Even if that doesn't solve it, its a good idea to do this as part of normal maintenance.

 

Good idea. Planning on doing that tomorrow. I'll let you know if it helps with this issue.

 

The most likely cause is the rear drive shaft shaking around in the carrier bearing. Some people suggest testing it by trying to accelerate in 4wd, BUT, while the test coming out "smooth" in 4wd proves the association with the rear driveshaft, being able to duplicate the "shake" IN 4wd does NOT DISPROVE it.

The reason is because of variations in TIRE WEAR.

The purpose of the test in 4wd is to UNLOAD the rear driveshaft and have the vehicle accelerated by the front, HOWEVER, if the front tires are more worn (slightly smaller circumference) than the rear, then putting it into 4wd does NOT unload the rear, so the test is inconclusive.

The only CONCLUSIVE way to test the rear driveshaft in 4wd is to remove it entirely. However, a better way to test it is to mount a camera to the frame pointed at the carrier bearing and repeat the test in 2wd. If the video shows the shaft shaking in the carrier, then you have your answer.


Now I'll tell you what I notice on mine... I have a "little" bit of the shake when taking off in 2wd (which is not present in 4wd). It wasn't there when the truck was new. One difference I've noticed since the vehicle was new, is that the carrier bearing now sits lower in rubber buffer. I guess that with age, the rubber has softened, and the bearing now hangs down a bit lower, which alters the geometry slightly. The slight shake I have doesn't bother me much, if it gets noticeably worse, I might replace the carrier, but after my Nissan truck (that thing gave new meaning to the word "shake"), it really seems insignificant.

 

Very interesting tgear.shed. I may have to try putting a camera on the carrier. I lubed the u-joints yesterday and tested roughly how much moment there is in that carrier. It didn't seem to allow too much movement or shaking but I don't know just how tight it should be.

 

Try pushing it UPWARD. It probably won't move much side to side because of gravity.

 

My barely noticeable 20mph shudder got a lot worse when there was 200-400lbs. of weight in the bed. It was a rear U-joint. After that fix, It soon began to shudder again. I installed Ride-Rite air bags about a week later, and It stopped. I don't see how this mod changed any driveline angles. Maybe a small center of gravity shift, since I now keep the truck an inch higher in the back. Doesn't shudder even with heavy loads in the bed now.