Shudder/vibration at 40mph.

What would cause a vibration or shudder at 40mph? If I speed up or let off the gas it goes away. Also in 4th and not Drive it doesn’t happen at all. I’ve read forums and seen quite a few people with thus problem.

 

It could be wheel bearings or the flawed factory design with the needle bearing on driver side. I’m not familiar with the terminology but I know that ECGS makes the remedy for it. Both these can be the source of the vibes.

 

It may be convertor shudder.
Here is a great way to test it. Special thanks to member Gearcruncher for the “How To”


Here is how you can test for a converter shudder from home .

Allow the truck to warm to operating temp . Your converter will not lock up when its cold .
Place the shifter into the overdrive position and drive until you feel the converter shudder .
Once you begin feeling the shudder , use the " Brake Tap Test " to see if the shuddering goes away .

As soon as you feel the shudder , use your left foot and gently tap the brake pedal about 1/4 inch down but leave your right foot steady on the gas pedal .
The idea here is not actually hitting the brakes but manipulating the brake switch . Manipulating the brake switch tells the computer that you are coming to a stop . Your computer will then command the converter clutch to the off position for a couple of seconds . When the converter turns off , your shudder is going to go away for a brief moment .
Because , you only tapped the brake pedal to manipulate the brake switch and you still have yourright foot steady on the gas pedal , the computer in your truck will then command the torque converter to re-apply the locking clutch and your shudder will instantly return .


https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

If it was needle bearing or wheel bearing I wouldn’t think it would stop if I drive in 4th.

 

I had some vibes that came from my drive shaft u joints. Give the shaft a shake and see if yours might be bad