1st gear low speed shudder HELP

Truck: 2007 Tacoma TRD Sport 4x4 auto trans 244k miles, stock suspension height, has had the recall for leaf upgrade done

Symptoms: From a stop, or from a very slow roll, there is a shudder (decent vibration, probably 5-6 shudders) for a second or two around 5-15 mph, until it shifts into second gear. It happens everytime. Seems to be worse when the truck is warmed up. Every other gear shifts perfect.

My dad's a mechanic, but not a tacoma expert. He initially thought drive line, but said all of that checked out ok. Then he said maybe torque converter, so we did a full tranny fluid exchange with some BG conditioner. No change.

I've poured through the forums re: tacoma shudders. From what I understand the normal torque converter shudders happens around 40mph? This allows you to do a brake tap test to see if the shudder goes away. But at 5 mph and upon accelerating, it's impossible to brake test. I've seen possible VVT solenoids. Axle wrap. Driveshaft needs balanced...etc etc. The truck has no codes or lights on the dash.

Any ideas? Any specific tests that can be done to confirm diagnosis. He has access to pretty much any dealership tool there is available. I don't want to waste his time as he has a shit ton of projects going already.

TIA

 

@gearcruncher is essentially where all my forum reading knowledge came from

 

The clutch inside your torque converter only comes on after the truck is warm .
If you feel the shudder when the truck is cold , you can eliminate the converter .
Judging by your explanation , i also think this is more related to a driveline issue such as tires and driveshaft angles .
Factory suspension sags after some time even with tsb springs .
Have you tried adding weight to the box of the truck to change the driveline angle ? its a cheap test
Universal joints good ? need to be greased at every oil change

There is a process of elimination list here
https://www.tacomaworld.com/threads/vibration-diagnostics-for-all-tacomas-write-up.520607/

 

Amazing. That's what I was looking for.

I did add 100# of sand bags, and then put on a new topper, which probably weights another 100? I did not notice a change in vibration.

T-SB-0249-12

Going to start assuming it's a driveline vibration until I rule that out considering the truck does vibrate when it's cold, albeit it seems worse once it warms up. This TSB mentions 15-25 mph, which is 5-10mph more than where I feel mine, but it's close enough and I assume there is some variability there.

I will try to update post when/if I come to a successful conclusion.

 

Well we removed the rear drive shaft and drove truck in 4H. The vibration went away. All the joints and bearings are fine. Now we are trying to measure driveshaft angles to see if we need shims?

 

Our 2010 started having the same kind of shudder you describe (except it does it cold, too) after we replaced the suspension and tires (going from 265/70/16 to 265/75/16) and lifted the truck 1.5 inches (a little higher in back, because we went with heavier-rated springs). Our shudder is in the rear. Looking forward to your findings.

 

This is good news .
One step closer to finding the issue.
Toyota says to rotate those tires every 5k .

 

How much play was there in the carrier bearing rubber bushing? If the rubber bushing is worn and the carrier bearing itself can move radially, that certainly can cause vibrations at low drive line rpms.

 

Finally got around to installing those 3 degree shims. I would say it improved the shudder about 80%. I can still feel a little vibration at the same speed. I'm not sure if installing a 4 degree shim would of rid of it completely. Seems odd the truck, with stock suspension would need that much of a shim for normal operation

 

So to follow up my own post in case anyone has the same issue and is looking for resolution. This last weekend I went ahead and installed an old man emu 2.5" including 3rd gen OEM tacoma leaf springs with an add a leaf pack plus new shocks and struts. I left the shims installed as well. The shudder as has gone away. So I assume the issue was due to some kind of weak leaf spring issue causing axle wrap or binding issue. Hope this helps.