2005 trans shudder?

I am the original owner of a 2005 tacoma 4x4 w/ 128k miles that has developed a pretty bad shudder. It used to only shudder at low speeds 10-20 mph like rumble strips, but it has since changed to all speeds. The magnitude of the vibration correlates closely with the amount of applied throttle - accelerating hard makes it vibrate worse. Coasting or neutral and it disappears. The truck idles fine and seems to shift fine. Sometimes it cruises smoothly at 55+, sometimes you can still feel a minor vibration at high speed. In 4wd the shudder is just as bad.

I took it into a local auto shop and a mechanic and his manager said it the low speed vibe was due a bad tire with a flat spot. They rotated the tire from the front to the rear and the truck drove a little better. I had the bad tire replaced under warranty as it was fairly new and it felt much better but the issue returned over the next 500 miles or so. I then had an alignment done, the trucked was toed in too much. Then I took it into a different auto shop and asked for a transmission drain and fill. They refused to work on it saying I need a new transmission. As they were assessing my truck behind the shop I heard them doing burn outs on it - it drove awful on the way home.

So I did a transmission drain and fill myself - replaced about 3.5 qts using valvoline maxlife. It seemed somewhat better. Then a couple days ago I did the full pan drop, cleaned pan/magnets, replaced the trans filter using 4.5 qts maxlife. I also added two tubes of instant shudder fixx. It seemed to drive smoother especially right after the last change. The transmission makes a minor fan belt squeak sound between 0 and 5 mph and the shudder is still present at pretty much all speeds. The truck seems to shudder more now its been a few days since the last drain/fill. I also tried the brake tap at speed test and I dont think it makes a difference so is my trans shot? Probably not the normal torq converter issue everyone has? I'm thinking to try another drain and fill with lubeguard plat.

I did have the leaf recall done perhaps 6-8 months ago I wonder if thats somewhat relevant. I also had a drain/fill done at the dealer in 2008 when the truck had only 40k miles on it seems odd to think the trans is already shot. Thanks for any help.

 

Have the u-joints and carrier bearing been checked/replaced, a stiff or worn out u-joint can cause a vibration at all speeds.

 

the ujoints and carrier bearing are original - i havent checked them and am not sure how to do so, but I was thinking if a ujoint or carrier bearing was causing it, when i put it in 4wd the front would be pulling the truck and reducing the stress on the rear drivetrain and reducing the magnitude of the vibration, but the strength of the shudder remains the same in 4wd

 

You can look at them and see if there's anything obvious but the best way to check them is to drop the driveshaft and make sure they all move freely and there's no play in them.

 

The transmission holds about 12 qrts. Maxlife is good. You can try lube guard red additive. I use Amsoil SS blue cap atf in my 15. I would disconnect the return line going back to the transmission and do a full fluid replacement with Maxlife. Get a gallon jug and measure 3.5 qrts of fluid. Add 4 qrts till the fluid looks bright red. Add the lube guard and see how it runs. It may take a little bit to work.

 

Here are two additional observations on the vibe/shudder that I wonder if would help narrow down the source better:
1) The vibe is less pronounced when the truck is cold and conversely its worse after things warm up/loosen up.
2) Sometimes the vibe has a sort of cyclic hum when cruising. Every couple of seconds the frequency of the vibration will change between a higher frequency sound and a lower freq sound. When its doing this and I shift gears the vibe pattern and oscillation remains the same - which makes me wonder if its a drivetrain issue and not a tranny issue?

 

Update:

I pulled the driveshaft off and drove it around in 4wd (front wheel drive tacoma). It drove great - no shudder or vibes. The carrier bearing seemed to be completely worn out and the ujoint near the trans was somewhat wobbly. I rebuilt the drive shaft with 3 new ujoints and a new carrier bearing, reinstalled the driveshaft and have minor/moderate vibes now - its definately better than it was with the old worn out stuff but not as good as it was driving around without the rear driveshaft. I had trouble pressing in new ujoints, some were fairly stiff to operate after pressing, is that normal? I noticed after driving about 20 mins the driftshaft was fairly warm to the touch, esp near the new carrier bearing. Is that normal? I wonder if I have something too tight or improperly seated. I'm wishing I would have bought a driveshaft assembly instead of tackling this project - looks like Amazon has a complete assembly around 330 probably junk? Maybe I could get a quality tom woods driveshaft for not much more?

 

I tap each side of both yokes with a hammer after installing the clips and that usually makes them loosen up.

 

An under filled transmission will have sloshing fluid issues. If you emergency stop, it may slam in to gear. It may have minor issues of shuttering that can be over looked. This can eventually lead to transmission failure.

 

any weights left on that driveshaft? time for a balance? is it phase matched correectly?

https://www.youtube.com/watch?v=dt69zYAcXME&ab_channel=WeberAuto