Really Needing Advice

I had the TC shudder and a drain and fill fixed it for me. Your symptoms seem different from what I had. For me it seemed as if the truck was shifting into overdrive to save gas when coasting (1200-2000 rpm 35-40 mph). When I feathered the throttle to maintain speed it would shudder like a rumble strip until I let off the gas or accelerated more. There's a brake tap test to check for TC lock up. This post describes the brake tap test: https://www.tacomaworld.com/threads...sion-shudder-any-advice.772383/#post-27588697 There's this post with almost too much info: https://www.tacomaworld.com/threads...econd-gen-4-liter-trucks.289913/#post-7301737

My co-work had also had an issue similar to the TC shudder, but it turns out his read diff breather was corroded and stuck.
Changing spark plugs might also help depending on how old they are.

 

You're on the right track! Keep chipping away at it. I would flip the carrier bearing bracket next. It's easy and just might help.

Loose or tired or damaged leaf springs could be part or all of the problem, too, but if that were it, I wouldn't think it would just disappear when going in to 4WD. That kinda leads me to believe torque converter is suspect, but fixing that's a very involved effort so I would check and make sure literally everything else is not the problem first.

Also...didn't ask: is your truck newly lifted?

 

Truck is stock! Only thing that has changed is I went from stock 245/75/r16 tires to 265/70/r16 with stock wheels from 3rd gens on those tires as well. That was done almost two years ago.

 

I really hope it’s not a torque converter problem… are there any more obvious signs that it likely the torque converter?

 

Not to my knowledge, sorry. After I replaced one component to the next without any change in shudder ( u-joints, carrier bearing, leaf springs under recall, added Lube Guard), the carrier bearing bracket flip finally fixed it, so I stopped researching. But there is info on Tacoma World about torque converter shudder issues so I'd recommend doing a search on it. And Gear Cruncher suggests adding Lube Guard to these auto trannies anyway so might be worth just doing that for some added protection, especially since you know your way around the fill plug. If the Lube Guard helps your shudder problem, it's likely the issue is in the torque converter.

On another note, I ask if it's lifted as some have reported angle shimming the leaf springs fixed their shudder on lifted trucks but not the case with yours. I have no reason to believe a slightly bigger tire would cause any of these issues, either. A mechanic saying the leaf springs were loose is a little strange. Might be worth just looking over the leaf springs for cracks or that one doesn't look signicantly different than the other.

 

Thank you guys for your advice. Will provide update soon.

 

Haven't visited this thread in awhile, but I PERSONALLY think it may the FP. For anyone experienced in trans shudder, can it even happen at IDLE as described by OP? Seems TO ME that the sudden drop in gas level right after fill is kinda indicative of a problem with the level float in the pump, and by extrapolation the pump itself.

TO ME, the issue at incline also kind of points to this direction, since there would be an increased need for fuel while going uphill, especially where it was sudden transition and the transmission was in a higher gear at that moment?

 

After reading this my thoughts are to change out the transmission fluid again, just to verify everything good

 

Update:

Changed spark plugs, cleaned MAF and throttle body (which was extremely dirty). Seemed to help a bit with the vibration. But still having a rough shift into drive and reverse and idling roughly when in either of those gears. I can very clearly hear the shift happening in the transmission fluid box (not sure what the correct name is)

I also hear a slight whining sound coming from this part circled in green... there’s is also an O2 sensor in front of it

Planning on doing rotation and rebalance tomorrow. Not really sure what else to check at this point since there are not any lights coming in the dash indicating any issues… not at this moment at least

 

That is a catalytic converter protected by a heat shield. It is very common for those heat shields to become loose and rattle. When its cool, grab it with you hand to see if it is loose. The catalytic convertor isn't going to make any noise, but a loose heat shield will.

 

is it also common for that shield to get loosey goosey on a 4cyl Reg Single cab 4wd with AT?
got a relative with an '11 single cab (92K miles) that has a VERY annoying rattle on the passenger side (been rattling for more than 20k miles now) that pops up at slower speeds over the bumps in the road, sometimes it is very loud, sometimes not so loud, and sometimes there is no rattle at all. it perplexes me after spot checking several things. the 4cyl has no exhaust routing under the driver side so that can be Ruled Out!

 

I am not sure what is common for a 4cyl, as I have never worked on one. I would think there is a high probabilty that the heat shield design is common between a 6 and 4 cyl. On my 6cyl, the bolts holding the two halfs of the heat shield rusted out. I just bough new boths, painted with high temp paint, and then installed them. I've read a few owners just pulling the heat shield off completely to reduce the rattle. If you grab the sheild with your hand and you can move it, that could be a source of the noise. The shield should not move around on the cat.

 

UPDATE:

This post has been a while but I still have been slowly working away at this acceleration shudder. Ended up having the carrier bearing replaced again because the shop noticed it was torn in places ( I did not notice tears) but was curious to know if this would make a difference and it DID NOT.

So.. I am very confident that the driveline is not my issue.. there is concern with torque converter and was recommended to get the transmission checked. But once again, no definite answers or a resolution.

Anymore thoughts?
Thanks everyone

 

My truck has the slight 2nd gen shudder on takeoff. It was there when I got it at 104k. Currently at 136,000 miles and it's still there: Transmission flush and fill (Toyota W-S w/filter performed. No change but not any worse. I really think it's the carrier bearing. No way the A750-I is breathing it's last at 136,000k. I tow a sled trailer on occasion with all of the normal essentials and the slight shudder is still there: Hot-Cold-Wicked Cold: doesn't matter.

136,000 is: "break-in miles" for this Aisin transmission: a wholly-owned subsidiary of Toyota. Volvo used them for years in the 8'0's and 90's....

"I ain't worried 'bout it right now"

 

I did a drain and fill about 20k miles ago but that did not make a difference. I haven’t checked the fluids since they were all changed at the same time

 

To add: FWIW, I only feel this phenom/issue when I really get on the peddle hard from a dead stop for whatever reason. I'm not chasing it any further before 200k miles

 

What is FWIW?

 

FWIW= for what it’s worth

 

If the OPs shudder was a fuel delivery issue the truck would fall on it's face anytime fuel demand is high. Likelihood of this being a FP problem is extremely slim at best. Most of the fuel that gets pumped by the fuel pump out to the engine ends up being returned to the tank via the fuel pressure regulator, the volume of fuel delivered to the engine is significantly more then the motor requires on purpose.

Suspecting this is the fuel pump is easter egging without any other symptoms pointing to fuel delivery. If the engine was starving for fuel you start seeing codes like a P0171/P0174 (lean condition bank one/two) if the pump is marginal but still working and the motor would fall on it's face when you put your foot into it if was bad enough to cause symptoms during normal operation. A fuel pressure check is all that's needed to verify but IMO it's highly unlikely for the OPs issue. Transmission shudder is not uncommon on these trucks and it's almost always the TC or tranny on non lifted trucks.