Bad vibes, Stumped on Stopping Vibrations on my 2000 Taco

When I bought my '95 a few years ago, she had a bad vibration that would start around 40-50mph and get progressively worse. Nothing subtle about it, at all.
Assumed it was the old, dried out tires, since she came out of Nevada. Ended up being the front wheel bearings.

5sp, 3.4, Xtracab

 

Tylerb
Dang thought I was on to something

U mentioned prior owner might of chinched out on new clutch in the past
IMO, there would be 5% chance that he paid the $40 to resurface the flywheel

possible so glazed/groves unbalanced?
Like u stated, could be the issue

I know some manufacturers have a ‘inspection window’ on bell housing
Unk if our Tacos have thou

plz let everyone know what u find

 

I have been fighting a vibration recently in my truck. I'm thinking its related to exhaust since I replaced the manifold with an LCE header but getting under the truck it barely vibrates.

When in D or R only after the truck is up to normal operating temp and idle is down to normal (650ish) the truck shakes like absolute madness. When decelerating around 20mph I have a shudder which I'm fairly sure is related to the torque converter if I shit into neutral the shudder is gone. Same thing during idle if I shit to neutral it goes away and is smooth.

Can a failing torque converter produce these issues at idle? Besides that one shudder around 20mph the truck is smooth and responsive. I've replaced just about everything except engine/trans mounts and the trans mount is going to be swapped in a week or 2 since I found some rubber separating on it.

No codes, no misfires, cleaned TB when fuel injectors were replaced, IAC responds well according to my scanner, fuel trims are as good as its gonna get on an old truck (LT around -3), no vacuum leaks as far as I can tell, plugs/wires changed ~15k ago

 

I’ll add in that I also had old rear drums that caused my vibrations. New drums and shoes made a big difference.