Overdrive vibration

Good morning, there are countless of threads of tacoma vibrations but I cannot find one that relates exactly to my situation. I’ve got this vibration from 30-40 mph in overdrive at medium gas but I can accelerate through it and it will stop or if I take my foot off the gas it will go away. At first I thought it was transmission related so I brought it to a shop and they hooked it up to the scanner and they didn’t believe it was the transmission but I had them change the fluid anyways, didn’t help. They suspected it would be the carrier bearing or a u joint that is a little stiff. I replaced the carrier bearing and all three u joints on the rear driveshaft. None of them helped so I decided to take the rear shaft out and drive in 4 high and it still had the vibration but not as severe. Figured ok maybe it’s the rear end even though this is the second rear end in the truck. I drained the fluid and there wasn’t an alarming amount of metal on the drain plug. Any ideas??

 

total mileage

why 2 prev rear ends

3 u jooints ......carrier bearing inadvertently could be out o phase

 

It’s got 210k on the clock but the only thing original on the truck is the front diff and the transmission. I knew the previous owner and the rear end needed to be rebuilt so he decided to buy a new one.

 

Sounds like u-joints Which are all the same part number. Or your carrier bearing need replacing
I would suggest that with the low cost. Doing everything

 

I replaced them all this week and even without the driveshaft in the truck it still does it so it can’t be the shaft.

 

Do a google search for torque converter shudder and "rumble strip"

 

You shouldn't be in OD at that speed. But the way these trucks transmissions are programmed it will shift to OD too soon. If I'm driving in a place where top speeds will never exceed 40-45 mph I shift out of "D" and put the truck in "4". At that speed IN OD your engine is really lugging and struggling. I'm betting that is the source of the vibration. Try driving in "4" and only manually shift to OD after you're at sustained speeds over 45. This may, or may not stop the vibration, but the truck has more power, gets better fuel mileage and you'll be a lot happier.

 

Output shaft bearing?

 

When in overdrive, can you tap the brake pedal for a sec and get it to go away.
(You will still need to be applying the gas to maintain speed)

Gearcruncher has a great explanation here.
https://www.tacomaworld.com/threads...th-pics-for-second-gen-4-liter-trucks.289913/

 

i agree

a compression test cold will probably yield UNeven ignition pulses

I would never drive 30-45 mph on OD ................Ur perogative

 

Thank you guys for the tips. I started driving in 4 under 45 instead of D and the shudder is gone.

 

5th is only good 55mph =

i never drive below 2300 rpms any gear.....................sweet spot for my engine I4 6speed

Ur taco may be diff engine /trans / rear end