I have a 2004 Toyota Tacoma Prerunner TRD V6 Truck. I have noticed that usually between 50-60 mph, I get a vibration from the rear (I feel it in bottom of seat) and it usually causes the bed to shake only on the left driver side. The tires are Runway Enduro HT’s which after some research, I have found out they are sold only for Tires Plus. I have had the truck in to Toyota 2x and I also did a road force test @ Tires Plus. Toyota says they have inspected shocks, leaf springs, driveshaft and axle and can’t find it. Toyota tells me the tires are the issue, but Tires Plus say it isn’t the tires because he put 2 new Bridgestone Dueler HTs on the rear and it didn’t go away. It might be a wheel, but to have 3 (2 rims + spare rim) be bad is highly unlikely. Tires Plus checked the suspension and didn’t find anything. I myself did notice that one of the bottom most leafs on the RR is slightly kicked out. Toyota Service Mgr said that is okay and would not be causing it. Toyota the 3rd time put different rims/tires on it and it did better (but it was only up to about 55 and on one road, not the 60 miles I drive a day). I am not convinced it is the tires. I have one person saying yes and the other saying no. What is really strange is usually early in the morning, it doesn’t do it sometimes. I have also moved tires around and even balanced the brand new spare and put it on the LR and the problem is still there. I would be more angry if I buy new tires and it still does it. Does anyone have any ideas, thoughts, or suggestions? Thanks.
I have the same problem, this sounds exactly like what is happening to my 2001 tacoma. I t doesn’t happen all the time, but gets worse the longer I drive. They put new tires on before I bought the truck, about 15,000 miles ago.
Put some weight back there and see if 400 pounds will change anything. Try tie downs across the bed from one of those holes to the other. These are goofball suggestions but Ford did things like this on the old Mustang to stop the shaking. Look at the braces Ford put right under the hood. After tricks don’t work, maybe smarter people will have a suggestion. I’m out.