Shuddering Under Acceleration

2002 Tundra TRD SR5 206000 miles.

Today on my way to work I noticed the vehicle shuddering. (much like one would shake with a fever if that helps)

Mainly between 50-70mph whilst accelerating.

On the way home, this was the case as well, but experienced some vibration when I was first getting going. I let the truck warm up before going anywhere to make sure everything is up to temp. Once I got off the highway to my neighborhood, it wasn’t shaking at low speed anymore. It hasn’t died on me, but did have a bit of an idle dip one time pulling out of the lot.

the shuddering itself wasn’t too violent, but was definitely noticeable.

Gauges all look good. No flashing check engine light.
I’m guess transmission or torque converter, but I am not the most mechanically inclined.

Historically, there has been some slip, or catching, rather when going from 1st to 2nd, but this vibration is new.

Let me know if anyone knows what’s up!

 

Is it shuddering when the torque converter locks up and goes away when not locked? Could be the torque converter lining/spring dampners or valve body not holding fluid pressure. Not much to go on unless a specific code is seen like p2757 for TC lockup.

 

In my experience the "older" first gens will take their sweet time to give you a check engine light for a misfire. I'd bet you have a bad ignition coil.

 

x2

 

Supposed to be 2 consecutive drive cycles but you’re correct, it has a mind of it’s own at times. It might possibly have a pending misfire code if poster has code reader.

 

I'd check for a pending misfire code. The ignition coils on our trucks are famous for going bad and causing misfires, but it often takes the truck a while to actually throw a code. In the past when I have had a coil go bad, I've had to hold the gas and the brakes at 50+MPH to get it to throw a code. The dip/hiccup at idle also sounds like it's a misfire to me.

 

Could be misrouting of the crankshaft position sensor wire during timing belt also, and the harness is getting damaged by pulley.

Could be the mounting bolt/ground is bad (corrosion) on one or more packs, or the connector plastic had its tab broken and isn't making constant contact.

Could be one or more loose/cracked vacuum hoses, especially thinking about the one that goes from the fuel pressure regulator above bank 2 over to the boxy part of the OEM intake tube.

Could be something stupid like dirty MAF, dirty throttle body, something stuck on MAF, like shred of paper from air filter, or oil residue if OP is unfortunately using K&N or similar style oiled air filter.

Could be they did something stupid like buy their spark plugs on fleaBay/scAmazon and got counterfeits, as is par for the course, and their plugs are dead already, or worse, broke off into the cylinder.

Could be the fuel pump is finally giving up the ghost, bad gas, or someone replaced the fuel filter with aftermarket fuel filter that's all clogged up, as aftermarket fuel filters do on these trucks.

Could be that one of the fuel injectors is finally giving up the ghost...

*** tl;dr - there's so many friggin' things that could be the cause, spark/fuel/air metering alone, not to mention wiring, but ... since @Beans1921 didn't bother to tell us which engine his truck has, we're legitimately pissing in the wind here...

It'd also be helpful to know the maintenance history, like the last time the timing belt was changed, since timing could cause this, and the timing belt on our V8 engines needs to be replaced every 90k or 9yrs (or 100k/10yr) and failure to do so can brick the engine if the belt snaps. Timing being off a tooth, or the timing belt being stretched/failing could cause the symptoms.

Too many possibilities. Not enough info to offer a reasonable diagnostic.