Transmission Shudder

Hello all! Looking for some advice on a transmission shudder on my 2005 V6 with 251k miles. I’m experiencing the shudder when I reach 20, 30 and 40 mph and it will stop once I’m in between those speeds. Once I get over 40 it’ll stop completely. Took it to a shop that concluded it was transmission related and didn’t want to drain and refill the fluid because of the mileage on the car. I’ve heard mixed things about changing fluid on high mileage vehicles. I’m wondering if it’s worth a shot since the transmission is apparently having issues anyways? Has anyone been able to solve the transmission shudder by changing the fluid/adding a lubricant like Shudder Fixx? Thanks!

 

I wouldnt add shudder fix
I wouldnt do a drain and fill
If you notice, if you drive a bit more aggressively, the shudder goes away. The shudder is typically from being in a high ratio, with high loads, at low speeds. The A750 in the earlier years of 4R was notorious for "lugging down" and running high gears at slow speeds. Its not uncommon for them to shift into overdrive at 40 and run about 1000rpm. If you try to climb any sort of hill and keep the throttle percentage low like under 10% the trans wont downshift, it will just lug more and more and shudder. Drive it a little more "spirited" and give it a bit more gas and force it to downshift.

I see situations where i know my vehicle is likely going to bog down or need a lower gear and i will force it to downshift. You can hold your throttle position where it is, and tap the brake pedal with your left foot and the trans will downshift and then you can modulate your pedal to accompany whatever load you are about to see such as a hill or whatnot.

 

Do a drain and fill and add the Shudder Fixx then after a few 1000s mile do anther drain and fill with the Shudder Fixx, most do this 3 to 4 times with good results, many have done this and many also have done a complete fluid replacement and I don't remember any that had bad results and most if not all had the shutter go completely away.

You really have nothing to lose trying this, if it doesn't help then you can go another route and have a transmission shop do whatever.

 

I had the same thing on my 2006. You felt the shudder especially going up inclines under 25mph. My transmission was up to date with drain and fill services over the years. My shop added some type of additive (can’t remember the brand) and that worked for about 3 weeks.

I found a transmission shop that I trusted and they said without opening it, it could be and likely is the torque converter. Very expensive to open/fix in its own. Sometimes replacing the torque converter doesn’t fix the issue.

We purchased the vehicle new and it’s in great shape. I bit the bullet and had the entire transmission rebuilt. Shifts like brand new. Aside from the shudder, I didn’t notice the shifts were a little rough until I drove it after the fix.

That was a year ago. Expensive, but I have 0 regrets.

 

Has the transmission fluid ever been changed? Shops don’t like doing fluid changes on vehicles in cases like this because they often get blamed for causing the problem; which can get worse after changing neglected fluid.

It sounds like you have a torque converter clutch shudder. This can be caused by physical wear of the clutch material, degraded (old worn out) fluid or a line pressure issue from normal wear and tear on the internal components… probably combination of all the above.

The Shudder Fixx is just a friction modifier additive that masks the problem… basically allows the clutches inside transmission to slip more before they lockup reducing the vibration (shudder) felt through the vehicle. It doesn’t fix anything that good maintenance may, or, may not have prevented.

250k miles is a good run for an automatic transmission. I would be prepared to rebuild or replace yours sooner than later.

.

 

I felt the shudder only once so far in mine..
I check the fluid level and found the dealership overfilled the transmission by 1/2-3/4qt on their drain and fill(perhaps wasnt the cause) anyways i dropped the pan, put in a new filter, cleaned the pan magnets and added instant shudder fix with the fresh 4.5qts of fluid it took to refill it..

So far so good.

 

@Bellafresh621 There’s good advice here, and I’ll add mine. While it’s true that the typical recommendation is to not replace high mileage ATF, you could do more of a refresh. Drain only the pan, add back that much new fluid (usually ~3 quarts). Drive and see if it helped. If so, awesome. If not, repeat. Continue for up to about 4 pan D&Fs and by then, the fluid will be close to fully replaced. I personally wouldn’t use a shudder fix product, at least until you’ve tried the full series of this.

Be sure to always check your level to make sure it’s correct.

Another personal choice of mine is using Toyota WS ATF. Some use Valvoline MaxLife and such; I just have trouble believing that one fluid could meet so many different manufacturers recommendations. I know WS works.

If cost is a factor with the Toyota fluid, a 25% off sale on OEM parts begins 11/24 - and you usually get that added onto the online discount many dealers offer.

 

I would have prefered to use a full synthetic such as Valvoline, but unless your doing a full flush(not recommended) you will be mixing fluids.. which is not ideal and could result in issues..

 

1 drain and fill using

$12 Lubegard 60902 Automatic Transmission Fluid Protectant, 10 oz

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