Anyone else with a 2nd gen Sienna? Shift quality?

[Huie83]

How does your transmission shift? Are the shifts soft and laggy when warm? IE, it goes to change gears and it doesn't flare but kinds hangs for a few seconds before it goes into the next gear? We purchased our 06 sienna (2nd gen is 03-08, 07-08 use the 3.5 and diff trans) last year with 83 K miles on it. It's always shifted great when cold, crisp quick shifts. After ~15-20 miles or 30 minutes of driving it starts to get sloppy-laggy-lazy shifts. Right when I got it I did a few drain and fills with Toyota T-IV fluid as the fluid was a little dark. Nothing abnormal on the drain plug magnet, just a little fuzz. Measured the exact amount I drained and refilled with the same. Checked the level after with engine running, hot and in park. It's exactly at the top of the hot marker so the level is spot on. A few weeks ago (I'm at 93K miles now) I was reading through the Sienna forums seeing if this was normal. Most posts said they had improved shift feel with Valvoline Maxlife ATF. I did 3 consecutive drain and fills in the same day with a short drive in between. The fluid is nice and pink, again correct level when hot. The shift quality has improved a little. It's not quite so laggy, but it's still not up to my liking. Thoughts?

 

[StevieC]

See if the transmission has a temperature sensor and try replacing it. I know there are some transmissions out there equipped with these that change the transmission shifts as it warms up and oil pressure inside the transmission changes to try and keep it feeling the same all throughout but if the sensor is bunged up it can affect the shift quality because it's not properly reading the fluid temperature. Not sure on this generation of Sienna but I would look there first. Also check to see if the cooler is thermostatically controlled. It could be when the thermostat opens to allow the fluid to go to the cooler that it's not circulating properly and as a result is affecting the oil pressures. These can get bunged up with crud over time.

 

[Oro_O]

What you describe is very normal for that transmission and the way it is programmed. There are a few ways to minimize it. OTOH, the U151E is an extraordinarily reliable transmission and if you change the fluid periodically, it will outlast the engine or vehicle in most cases. 1st is to use a T-IV spec fluid. This is thicker than Maxlife and the DexVI/Toyota WS fluids. So stick with that as the thinner fluids exacerbate it. If people reported it was better after adding MaxLife or similar, I would check if a) they were replacing worn fluid vs. fresh T-IV, and b) if they corrected a previous underfill. You don't have to use T-IV, but use a fluid of that viscosity (e.g., ~7.2cSt@100C) Another issue is that it is just not possible to get an accurate reading when warm. The splash effect will get in the tube and always make it look full. First thing in the morning, start it, shift slowly down through all gears and back up. Then go pull the stick and just make sure it's above the Cold mark. Besides getting the right amount of the correct fluid in the transmission, there really isn't much you can do because the behavior is generated by in the PCU, not the transmission. Driving style makes a difference too, because the programming is adaptive. If you are harsh with the gas, this tends to exacerbate it based on a lot of owner experiences I've read on TN and a ClubLexus. If shifts start to feel harsh, check your engine mounts and the torque strut on top; these wear out.

 

[SatinSilver]

When was the last time the <span style="font-weight: bold">trans filter</span> was replaced?

 

[The Critic]

Some of the 5-spd autos had a TCM update available for shift quality improvements- the update is announced via a TSB. I just did a 2005 RX330 last week for this concern. Get a $15 subscription to TIS and see if there's an applicable TSB for shift quality, and if there is, I would try that first. Also, make sure the fluid level is not too high. It's easy to overfill these. Drive the car until it is very warm, then check the fluid level. At that time, it should not be higher than hot max.

 

[LeakySeals]

My Gf's dad has a 2010 AWD w/97k. I was in it last week, and noted the perfect shifts. Has some other crunching issue in the front end, but the transmission is prefect. And he beats it bad. Regarding Maxlife, look carefully at the dates of the posts. Its changed in the past year or 2. Its become thin. Very thin. A post on here said thinner than T-IV. I had an 02 Camry that died with a perfect shifting transmission at 345k. I never switched away from T-IV. I'm running Maxlife in my SUV, contemplating exchanging back to Dex-Vi. Seems to shudder when its hot out. Never did that prior, but the miles are getting up there so I wont know till I do the exchange. One last suggestion is Lubegard Red. Add 10oz, or 1 qt bottle depending on if you can make some room. Its one additive that can make a shifting difference.

 

[Oro_O]

Originally Posted By: The Critic

Some of the 5-spd autos had a TCM update available for shift quality improvements- the update is announced via a TSB. I just did a 2005 RX330 last week for this concern.

AFAIK, this is available for all the early U151E - HOWEVER, most who had it done reported a 10% or more reduction in MPG and an only partially satisfactory result. And it's not reversible, once it is flashed, there's not kit or code to re-flash it. A lot of owners were really dissatisfied with this update and as word spread, people quit getting it done as the mileage penalty was stiff (~29 down to 24 mpgs hwy on the ES and Camry models).

 

[michaelluscher]

Same engine/trans combo in my '06 Camry Identical complaint I'm gonna start checking mounts, and doing one last service with straight up T-IV/3309 I used Castrol Transmax IMV, didn't like it at all I also put LGP in 3309, not happy with that shifting either

 

[Oro_O]

Originally Posted By: michaelluscher

I'm gonna start checking mounts, and doing one last service with straight up T-IV/3309 I used Castrol Transmax IMV, didn't like it at all

Have someone shift it while on the brake while you watch from in front with the hood up. Loose mounts should be obvious as it should sit perfectly still through this procedure. The top "dog-bone" strut breaks often. Of the lower ones, the two side mounts (behind each wheel) are the most likely; the front one is less breakage-prone, unless the dog-bone was broken a long time on top, and then it is over-stressed. I have heard that complaint re: IMV, though no experience with it myself.

 

[SatinSilver]

Napa carries T-IV. https://www.napaonline.com/en/p/AORATF0T4

 

[Olas]

Manuals shift exactly how you want, exactly when you want.

 

[wag123]

Originally Posted By: LeakySeals

My Gf's dad has a 2010 AWD w/97k. I was in it last week, and noted the perfect shifts. Has some other crunching issue in the front end, but the transmission is prefect. And he beats it bad. Regarding Maxlife, look carefully at the dates of the posts. Its changed in the past year or 2. Its become thin. Very thin. A post on here said thinner than T-IV. I had an 02 Camry that died with a perfect shifting transmission at 345k. I never switched away from T-IV. I'm running Maxlife in my SUV, contemplating exchanging back to Dex-Vi. Seems to shudder when its hot out. Never did that prior, but the miles are getting up there so I wont know till I do the exchange. One last suggestion is Lubegard Red. Add 10oz, or 1 qt bottle depending on if you can make some room. Its one additive that can make a shifting difference.

+1 You definitely want to use T-IV transmission fluid. Lubegard Red does help but the improvement is subtle.

 

[michaelluscher]

Originally Posted By: Oro_O

Originally Posted By: michaelluscher

I'm gonna start checking mounts, and doing one last service with straight up T-IV/3309 I used Castrol Transmax IMV, didn't like it at all

Have someone shift it while on the brake while you watch from in front with the hood up. Loose mounts should be obvious as it should sit perfectly still through this procedure. The top "dog-bone" strut breaks often. Of the lower ones, the two side mounts (behind each wheel) are the most likely; the front one is less breakage-prone, unless the dog-bone was broken a long time on top, and then it is over-stressed. I have heard that complaint re: IMV, though no experience with it myself.

I've already put a Toyota top dogbone mount on it Old one wasn't bad by any means, but I thought I'd start with the cheapest Side one felt OK when I did the trans pan last service, Guess I should check again

 

[TheKracken]

I have an 04 Sienna and the wife and I love this thing. I have noticed the shifting isn't the best but at over 280k miles I am just thankful it still runs! Planning to keep it for another 7 or so years and 350k miles before buying another! It's a top of the line model with awd.

 

[Huie83]

Thanks guys, I verified the fluid level today both cold and hot, it's spot on for both. I ordered a case of Toyota T-IV from amazon and will swap it out next week. I have a fluid extractor so I think this time I'll just suck it through the dipstick tube, measure and refill with the same amount 3 or 4 times with small drives in between to mix the fluid. I'll report back next week.

 

[SatinSilver]

Originally Posted By: Huie83

measure and refill with the same amount 3 or 4 times with small drives in between to mix the fluid.

I'd wait a week between drain and fills or 500 miles to get a nice, slow cleaning.

 

[TheKracken]

Oh another thing that will help is to disconnect the battery for a while. Since the Sienna transmission issues are mostly ECU related, resetting it with new fluid will usually help it relearn.

 

[Oro_O]

Originally Posted By: michaelluscher

Originally Posted By: Oro_O

Originally Posted By: michaelluscher

I'm gonna start checking mounts, and doing one last service with straight up T-IV/3309 I used Castrol Transmax IMV, didn't like it at all

Have someone shift it while on the brake while you watch from in front with the hood up. Loose mounts should be obvious as it should sit perfectly still through this procedure. The top "dog-bone" strut breaks often. Of the lower ones, the two side mounts (behind each wheel) are the most likely; the front one is less breakage-prone, unless the dog-bone was broken a long time on top, and then it is over-stressed. I have heard that complaint re: IMV, though no experience with it myself.

I've already put a Toyota top dogbone mount on it Old one wasn't bad by any means, but I thought I'd start with the cheapest Side one felt OK when I did the trans pan last service, Guess I should check again

You can judge this effectively just doing the visual test while someone else shifts. Any mount fault will be readily apparent.

 

[Oro_O]

Originally Posted By: TheKracken

Oh another thing that will help is to disconnect the battery for a while. Since the Sienna transmission issues are mostly ECU related, resetting it with new fluid will usually help it relearn.

This is very true, BUT - it has potential drawbacks. Some without experience have done it and fried the PCU, or blown the 100a main bus (which is $5 but a serious hassle to replace). Plus you loose all car presets, which are many. There is a better way. I have found just changing driving habits will re-set it in short order (<100mi). It appears the PCU (it is actually a PCU and not ECU, as it is a singular module that controls the the entire power train, not just the engine) has a very short memory. It is a single solid state unit behind the glove box stacked with the air filter. I learned this as my wife and I have very different driving habits - or used to. She had a very lead foot/heavy braking habit. She drove it daily. I could take the car for the weekend and drive smoothly, and the PCU would re-learn and smooth out the harsh shifts within 100 miles (distance to my parents and back). Then it would re-learn the bad habits by Wednesday after she put about 100/150 miles on it for work and errands. We went through this totally obvious cycle for two years. She gradually got a lot smoother and the swings disappeared. She grew up in Russia/Moldova and did not really start driving until 2003/4 after immigrating. So until recently, she was the equivalent of a lead-footed 18 year old. I've had the unique experience of seeing how this car works as a daily driver/shared driver, and researching it on dedicated forums. It's really a great powertrain, really actually fantastic, but has it's quirks.

 

[HangFire]

Originally Posted By: Olas

Manuals shift exactly how you want, exactly when you want.

Not when my wife is driving. And as usual, your "answer" contributed nothing.