Vibration problems

I'm new to Tacoma World and joined to discuss my 2008 Tacoma 4X4 quad cab driveshaft vibration. The vibration really started to show up at 50,000 miles and got progressively worse and the vehicle has 70,000 miles on it now. Over the past year I've had the Technical Service Bulletin fixes done, got new rear springs per the safety recall, tried firmer rear shocks, had the U-joints replaced on the Warranty Enhancement Notice, and still have a driveshaft vibration which I've confirmed with a vibration analyzer. The Toyota dealer's response has been that my truck drives like any other 2008 Tacoma, which is not an acceptable answer as far as I'm concerned. Has anyone had similar driveshaft vibration experience?

 

Welcome to TW! Have you tried replacing the drive shaft center support bearing ( https://amzn.to/2x4Ch9h )?

 

No, for several reasons. The dealer's position was that it wasn't the problem. They also said that they didn't just replace the carrier bearing, but replaced the whole drive shaft. The Toyota Warranty Enhancement Notice said that if the driveshaft vibration was not fixed by replacing the U-joints, that they would replace the driveshaft under the Notice. Toyota said that my vehicle didn't meet their criteria which was that the driveshaft had to make excessive noise. Mine did not make excessive noise so in my case I would have to pay to replace the driveshaft, which I was not willing to do. Personally I think the carrier bearing is worn and needs replacing, but I also think it's Toyota's problem if their design requires replacing the driveshaft at 50,000 miles. The fact that they've published a Technical Service Bulletin and a Warranty Enhancement Notice on this problem says something about the design IMO.

 

Here's the summary of my 2008 Tacoma saga. First off, let me say that after dealing with Toyota for over a year on my drive shaft vibration issue, I'd had enough and decided to get rid of the Tacoma and trade it for a new Honda CRV. The CRV is all wheel drive and has the same drive shaft configuration as the Tacoma, i.e., split drive shaft with a carrier bearing in the middle. After inspection, the biggest difference of the two is the drive shaft on the CRV is centered in the rubber donut, whereas on the Tacoma it sat lower than center (either due to wear or a less rigid rubber donut). Toyota always said that was not a problem. Given the similarity in the drive shaft configurations I decided to run the same vibration test on the CRV that I ran on the Tacoma, which was a 4-mile road test at 30, 40, 50, and 60 mph speeds with the vibration sensor placed on the frame at the carrier bearing. The test results show the frequency distribution of the vibrations from the road bumps which are the standard imperfections that you get on all paved roads, as well as any other vibrations encountered by the vehicle. With a firm suspension vehicle which both the Tacoma and CRV are, the road bumps are handled by the suspension but also can be felt by the driver. Toyota always blamed the ride on bad roads in our area, but they are similar to the roads I've driven on throughout the western U.S. I never had any problem with the road bumps I felt in the Tacoma. What I had a problem with was the added vibration caused by the drive shaft after hitting the road bumps. You can calculate the rotating frequency of the drive shaft by simply calculating the frequency of the tire rotation and multiplying by the rear-end gear ratio. On the Tacoma road test plot there are spikes at 25, 33, 42, and 50 Hz. (corresponding to the 30, 40, 50 and 60 mph speeds) on top of the frequency curve of the road vibrations. Those spikes are clearly coming from the drive shaft. On the CRV plot all you see is the road vibration frequencies. As you would expect with the CRV all you feel is the road bump and no added vibration of the drive shaft. According to Toyota I was and overly sensitive driver in what I was feeling, and the technician said that all they could do to find the problem I was describing was to "throw parts at it". Well, all I can say to Toyota is I'm one happy Honda owner now.