Tundra Transmission

I have a 2015 Tundra Limited with roughly 130k miles. I’ve started to notice some questionable noises/feelings while driving. It appears to happen in 3rd and 4th gear, but say I’m driving on a flat road and in 4th gear, if I let off the gas pedal, the engine kind of revs up then down until I push the gas again. I’m worried my transmission is going bad. Anybody have a similar feeling/issue while driving? Any insight is appreciated.

 

I think you should check that trans fluid first see if it’s low

 

There’s no dipstick for the transmission fluid under the hood, would this be underneath the truck? Theoretically if the fluid levels are fine, do you have any other recommendations? I know Toyota will charge you $120 just to do a diagnosis of the vehicle. Just looking for options. Thanks!

 

It is a sealed tranmission, there is no dipstick.

 

How can I check if the transmission fluid is low?

 

Yea no dipstick.

I only use WS Toyota Trans Fluid.

****Mod edit for incomplete data that could cause damage to transmission.***

 

Appreciate the detailed message Eddie. Thank you. I’ll check it over the weekend. Any other suggestions if it is full? Take it to a transmission shop?

 

Toyota Trans are actually pretty good Trans I hope that’s your issue they are big money to rebuild so let’s stay positive hit me up if you need any more help

 

I owned a 2015 and had a similar issue in 2nd into 3rd gear, which eventually moved to 3rd into 4th gear. My issue included what I described as a jump as the gears changed. My dealership tried, but reported no symptoms during the visit. After two visits, the service manager basically told me that I need to bring it in when it is happening. By chance, I was driving by the dealership and this issue was occurring. I popped into the dealership and the SM jumped in. We drove 5 blocks and it happened the whole time. I saw the SM lower his head and shake it. When I inquired, he said the tranny was done and needed a replacement. We drove back to the dealership and they gave me a rental. The replacement though rebuilt, was fully covered under the warranty. Sorry that you having this issue....it can be frustrated.

 

There is more to checking the trans level than listed above. The thermostat for the cooler needs to be pinned open and the trans needs to be close to cold (101-113?) not all the way up to temp.
Do some research- there are other threads here describing the process to check the level of the ATF.

 

Did you check to see if you have any codes?

 

No codes as of today.

 

Is it a cooler thermostat in the classic sense-running trans fluid- or a coolant thermostat that runs coolant through it to heat/'cool' the transmission fluid?

 

When was the last transmission service done? If I may ask.

 

Did he say why? How many miles at the time?

 

A 2015 Ltd should have the tow package which included an auxiliary cooler - not just the puck that’s on the 2019-2021. It has a button that gets pinned down to force it open allowing flow through the whole system while cold.

 

Do they look similar?

 

All Tundras have the puck that brings coolant to the transmission to warm the fluid, the difference would be you would see a thermostat with lines attached running to the front of the truck if you have a cooler. This is what the thermostat looks like, it would be attached to the transmission and then the warming puck is attached to this, on 2019-2021 there is a spacer to take the place of the thermostat.

 

Here's a good video showing the "button"

https://youtu.be/dlh0eyQevsc

 

Ok. So the warmer puck that's on all trucks just warms the trans fluid via coolant and I assume 'cools' when the trans fluid gets hotter than the coolant is?

 

Correct, just it does a very poor job at it and if you monitor your trans temps you wont ever really see it go down once it goes up it basically stays up until you stop driving.

 

I noticed this. Not towing, freeway speeds it sits around 210-220. Do you know the safe operating range of WS fluid?

 

typical “safe” operating temp is between 185-210. With a transmission cooler installed it will at times go above 210 but should drop down rapidly once transmission thermostat opens up

above 230 for extended periods of time can degrade the fluid and possibly cause damage. No one really knows the exact number when that happens. There have only been limited recorded cases where trans temp has really been an issue. The cooler was removed with the ‘19 models and up, so really too soon to have a mass amount of failures due to temps. But I’m sure they will be coming soon.

 

I bought my 2020 tundra used with 47k miles. Truck was in excellent condition you could tell the previous owner took good care of it. But he towed a heavy ice castle trailer with it. Had the truck for 2 weeks then one day the transmission started shifting all over the place then wouldn’t shift above 4th gear no matter what. Transmission was toast. Thankfully it was replaced under warranty. I think removing the cooler was a big mistake if people plan on towing a lot. I’m not adding a cooler yet but I’ll be replacing the fluid every 30k miles for sure. Towing my boat on a hot humid 95 degree summer day I see temps of about 220 with the converter temporarily spiking to 240. Transmission temp light comes on at 300 I believe. I’m going continue to monitor it and see how the temps do. But I think if you change(refresh) the fluid on schedule it should be ok. If I towed a big job trailers for work every day I’d probably consider a cooler.

 

Op I would do a drain and fill, if your high transmission temp light comes on you most likely burned the fluid by that point if you guys do any towing I would definitely get a transmission cooler if your truck is 19 or newer