08 sienna U151E 5 speed lubegard?

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930
Location
Southeast
I got this car about 4 years ago with 70k. Almost to 120k now. Its been flawless except for a dead battery at the most inopportune time from leaving lights on. I've done most maintenance other than a brake flush which a mechanic did. According to my records I've just done the 4th drain and fill of the Toyota WS trans fluid since I've had it. Each time probably 3 to 3.5 quarts is replaced. I did this in 2016, 2017, and now about 6 months or 10k miles apart twice in 2019. I have no idea if it was done at all before 70k. The trans shifts very well, especially under low throttle. Sometimes on the highway during passing, if the trans shift from 5 to 3, it will be a bit sluggish going back to 4, then it might hang in 4 for several seconds before shifting back to 5. I just did the last drain and fill a couple days ago, so I'll drive it for a bit to see, but I don't think the fluid is the issue. I left a little space in there with the last fill. Should I give lubegard red a try?
 
change filter if any, you dont have flare ups or shudder... sounds like a lazy/worn switch or solenoid, or could be clutch material/debris or varnish impeding its operation from in-spec upshifting times scanner that can read TCM codes if any lubegard red or platinum at 1-2oz per qt of trans capacity will help with cleaning varnished switches/solenoids and supplemebt lubricty with their patented esters is your fluid burnt smelling? do you notice this only in cold weather or at startup? maybe a full synthetic formula may help if that is the case
 
Are you even sure this is a transmission problem and not how the trans is programmed? I don't know Siennas, but I do know in my Outback with 4EAT if you're cruising at 50-ish and stand on it and it drops to 2nd and then you ease off, the TCM thinks you're trying to be "sporty" and holds the gear for about twice the time it normally does when there is no WOT involved. My Impreza is similar with WOT, but at part throttle you can tell it was programmed to try to get every MPG... if you just barely push the gas from a stop, the car is in OD by about 28-30 mph and sitting around 1200rpm... any additional gas whatsoever kicks it down to 2nd gear. Sometimes its annoying, but it's what they told it to do.
 
Messages
2,118
Location
Seattle-ish, WA
Originally Posted by SubieRubyRoo
Are you even sure this is a transmission problem and not how the trans is programmed?
My thought, too. I have a U151e in a Lexus ES. It has quirks in shifting sometimes and that is just how they are programmed. A lot of Lexus buyers were really peeved at this and forced Lexus to develop new software to flash the PCUs during the first couple years it was introduced, c. 2003-2003. The Sienna programming would be different, but could easily be as similarly flawed as building these very durable units was different than programming the controllers. Toyota showed less skill there. That on the table, we now have 315k miles on ours and it works flawlessly other than the very occasional hard downshift (programming issue). They were designed around the thicker T-IV fluid and I have found running the lower viscosity WS or equivalent (MaxLife, etc.) in them results in less satisfactory performance. And many other owners have noted the same. I don't know what changes they might have made in 2004/5 ish to the unit or programming itself to accommodate the switch to the (problematic and unsatisfactory) WS fluid. I use T-IV, Mobil 3309, or Idemitsu TLS only now after a lot of years and miles of experimenting, and it runs great. I do use 1oz/qt of Lubegard Red in it, also. If you do really suspect a valving issue, you could add a little Chemtool B-12 to it for a week before your next fluid change. I added about 3 to 4 ounces to a Honda transmission recently and it made a WORLD of difference - I then did two drain/fills and (last with Lubegard ATF itself, not just the additive) and it went from feeling like it was on the way out to feeling like new.
 
Oro, I think something that would be "safer" and an approved use of fluid, would be to double the dose of Lubegard Red, and add enough to treat the entire trans fluid capacity at a rate of 2oz per quart of trans fluid. I'm definitely no lubrication designer, but MolaKule has agreed with this treatment, and also said that based on the makeups of the fluid, he would ONLY recommend using Red, not Platinum, because it messes with the friction modifiers. I believe something was mentioned about the double dose "should" be able to help free up sticking solenoids IF they are able to be saved. But again, maybe check if there are any Sienna message boards and if this is a common complaint with programming fixes, or if it indicates an actual problem. Maybe call your local Toyota stealership, have them run the VIN to see if they can tell you the most recent TCM software in the vehicle, and if there is an updated version. I know, I know, none of us really like stealerships, but if this is a programming issue, the latest firmware may be able to resolve some of your concerns.
 
Messages
902
Location
Alberta
Same transmission in my 2005 is spec'd for type T-IV. Maybe slightly different programming for the thinner WS fluid,but mechanically it's the same. I use a bit of lubeguard red when I drain and fill.
 
Messages
2,118
Location
Seattle-ish, WA
Originally Posted by SubieRubyRoo
Oro, I think something that would be "safer" and an approved use of fluid, would be to double the dose of Lubegard Red, and add enough to treat the entire trans fluid capacity at a rate of 2oz per quart of trans fluid.
Yes, that would work, too. However, the Chemtool or SeaFoam use is recommended by the respective manufacturers for just this application; it's not exactly "off label." That said, I only do the stronger solvent treatment (B-12 or SeaFoam) when I am planning a drain/fill soon to remove most of it. Where I not, I'd go with the Lubegard Red additive, or re-fill with the Lubegard ATF which is "pre-treated" with the unique Lubegard add. pack. I don't think there were any U151e re-flashing TSB's on the Toyota side. They didn't deploy that transmission to Toyota models until a few years after the Lexus line, and they learned their lesson and "dumbed" it down. Also, the Lexus re-flashing is widely considered undesirable in the Lexus community now - it made the transmission much lazier and the car less responsive, though it did cure the occasional "clunk." The re-flashing was also only available under the initial power train warranty, and otherwise wasn't done.
 

FL-400S

Thread starter
Messages
930
Location
Southeast
The symptoms are at operating temp on the expressway, not cold. When it is warming up, it seems to shift every 10mph, ie it goes into 5th around 45 or 50mph, similar to other Toyotas i drove. I don't recall it hanging on the 4 to 5 upshift for the past few years. It turns about 2000 rpm on cruise at 70 in 5th gear. If I shift to 4th, it jumps to almost 3000rpm. I drove it on cruise this morning til warm, then gave it a couple 5 to 3 downshifts, and it quickly went from 3 to 4 to 5 within a few seconds. Seems normal now. Maybe the trans reprogrammed with less spirited driving, or the atf is working better? Still try some lubegard?
 
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Messages
2,118
Location
Seattle-ish, WA
Originally Posted by FL-400S
Seems normal now. Maybe the trans reprogrammed with less spirited driving, or the atf is working better? Still try some lubegard?
Could be either/both. I would still add some lubegard; it works in multiple ways. Put 9/10ths of the bottle in the AT and the last ounce in your PS system. Regardless of the add. pack., the ester oil will condition seals and reduce temps (slightly). It's worth it for that alone.
 
Messages
171
Location
VA, US
I always added LubeGuard Synthetic in my older transmissions (Ford, Hyundai). That IMO kept them alive and well for 20 years. LubeGuard sells also their own ATF, with pre-added compounds. In regard to Fuel Efficient, Low Viscosity transmission fluids, specified to be used in transmissions designed a couple of decades earlier, for normal ATF... I don't trust them, no matter what manufacturer says. They will do that to maintain their claims of fuel efficiency (MPG numbers) and they will hope that the transmissions will last past the warranty mileage. I want more miles on transmission for my money, I don't care so much about using slightly less fuel. My point - my 2011 Toyota RAV4 has a U151F transmission (4WD version of U151E). This is the U250E for V6 models. The U250E is a 5-speed version of the U241E. The 4 speed U241E appeared in 2004. The U241E appeared in cars in 2001! Those 2001 transmissions used non-LV fluids and are famed to last a long time. I am not so sure that the new LV fluid will do them any good.
 

FL-400S

Thread starter
Messages
930
Location
Southeast
Its driving fine. It still gets hung up sometimes, but I think it is pedal dependent. Not sure lubegard is doing much. I tried it one one or two vehicles previously, didnt notice much change.
 
Messages
171
Location
VA, US
Originally Posted by FL-400S
I got this car about 4 years ago with 70k. Almost to 120k now. Its been flawless except for a dead battery at the most inopportune time from leaving lights on. I've done most maintenance other than a brake flush which a mechanic did. According to my records I've just done the 4th drain and fill of the Toyota WS trans fluid since I've had it. Each time probably 3 to 3.5 quarts is replaced. I did this in 2016, 2017, and now about 6 months or 10k miles apart twice in 2019. I have no idea if it was done at all before 70k. The trans shifts very well, especially under low throttle. Sometimes on the highway during passing, if the trans shift from 5 to 3, it will be a bit sluggish going back to 4, then it might hang in 4 for several seconds before shifting back to 5. I just did the last drain and fill a couple days ago, so I'll drive it for a bit to see, but I don't think the fluid is the issue. I left a little space in there with the last fill. Should I give lubegard red a try?
I just did my first flush on my new-to-me RAV4 with almost the same transmission U151F 5 speed (AWD). Based on the dark color of the WS at 70k miles I would never, ever use that in it. Oxidizes like crazy and also absorbs moisture! For now I will keep flushing it (drain/refill) with Valvoline MaxLife synthetic till is coming out almost read and then replace the filter. As a side note those transmissions are slight modifications of their older 4 speed that were not designed for Low Viscosity fluids. Now that Toyota, like everyone else, switched to thinner fluids (for better fuel economy) I am curious how long those transmissions will last. Toyota T-IV that was specified before was great... and still needed to be changed at 30k miles (if driven in stop-and-go conditions, like... city traffic in most big cities).
 
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