Vibration from 24-29 MPH?

My truck has a noticeable vibration in 3rd gear from about 24 to 29 MPH, it feels almost like you are on a rough road. Any ideas what I should look for? The truck seems fine at all other speeds including highway.

Thanks,
Ron

 

I have the exact same problem. After the Leaf Spring TSB and the ECM Reflash I noticed it.

From what I can tell, it seems like the shift points are not calibrated correctly and the truck is waiting too long to downshift when coasting/braking.

Anyone else have any ideas on how to solve this? I just had it in the shop and the best they could do was balance the tires.

 

Bump - I'm about to bring it into the shop again for this problem. Anyone have any ideas?

 

OP, have you lifted the rear any?

Sportsphreek, yours is probably due to the Leaf Spring TSB due to a change in the driveshaft angle.

 

There's a TSB for this. T-SB-0132-08

 

No lift, and its a 4cyl AC with manual tranny. I'm stopping by the dealer today to take a tech for a ride, I hope they can fix it because while its not getting any worse it is driving me nuts!

I'm looking for the actually TSB, the one I found doesn't include my truck.

Thanks,
Ron

 

That would make complete sense- I KNEW it was along the drive train. Is there any known fix for it that the dealer can do when I bring it in on Monday?

-Kevin

Edit: Or would the easiest fix be for me to just get a pair of Bilstein 5100's and level the truck back out

 

http://www.tacomaworld.com/forum/2nd-gen-tacomas/136672-fixed-more-vibes-free.html