Transmission slip from 1st-2nd

My 2012 Tundra has 216k miles.

My father purchased it brand new and I took it over 5 years ago.

There was around 130k miles when I received the truck.

He was religious about all the maintenance since day 1.

He pulled a light weight work trailer with it over the years.

When I got the truck I started going through and doing some more routine maintenance. Spark plugs, k and n air filter, started using 0w-20 royal purple with k and n oil filter, brakes and a lot of other stuff.

At some point I realized it was due for a transmission fluid service. Everyone in the world warned me about bringing it to Toyota for a flush but the truck had been in for regular flushes every 30,000 miles when my dad owned it.

when I brought it in to Toyota and scheduled the service they did not want to flush it, but when I asked about their recommended service interval and how they recommend a flush every 30k especially when towing I mentioned it. They looked up the service logs on the truck and said okay. Yeah we can flush it because it’s been in for regular flushes.

this was approx 2 years ago.
I noticed as we went into winter here in Colorado that when I would take the truck for the first drive of the day (vehicle was somewhat up to temp but not completely) I found that after I drive out of the neighborhood and come to my first stop, when I let off the brake it felt like the tranny was not engaged and it would want to roll back if on a hill. Then after giving gas it goes high rpm, and if forcing the gas harder it would jerk here and there before a hard shift to 2nd gear.
This would happen 1 time the first drive of the day. The rest of the day transmission shifts normally.
Since the flush I have done my own drain and fill to avoid any problems from a flush because I believe that flushing it did cause some issue.
So I’m sitting here writing this because I find it super strange it only does it once for the day and it’s done. I’m hesitant to even ask Toyota about it because I feel that they won’t care as they didn’t really want to “flush it” Initially.

after scouring the internet I see some tundras have issues with the solenoids on these transmissions. However most of them are throwing codes and not shifting above a certain gear.

I’ve also stumbled across many videos that explain this shift issue could be a big variety of other things, I.e sparks, throttle body, maf, coolant sensors, the list goes on.

I prefer to do most of the work on my truck as I’ve had bad luck at Toyota and other mechanics around. My understanding of transmissions is most of the time if something is clogged or a solenoid is faulty, the truck carries the symptom full time and may throw codes. I have 0 codes and haven’t had any since I’ve owned it.

so I’m curious, can anyone enlighten me or has been through a similar situation as this?

when it is in between 1st and 2nd and is jerky I left off the gas and do a gradual increase on throttle and it seems to get through to the next gear okay. I feel if I just kept gassing it it would continue to jerk back and forth and then shift hard to 2nd.

thanks for reading, hope to hear some thoughts

 

Hi Crestyc, new member here just like you! From experience with AT, your symptom of transmission feel disengaged is due to a low fluid level. Keep in mind that fluid expand with heat and contract when cold. If your ATF level is just on the low limit then you could have issues as described.

You said that it occurs when you drive it for the first time of the day and your truck is almost up to temp (after idle warmup i guess) so your engine is warm but not your trans... Then you accelerate causing the fluid to move in the pan and cause starvation like described. After that, the fluid heats up, expand and the issue is gone for the rest of the day until sitting all night and fully cool down.

Just curious, automatic transmission have a special fluid level check. Have you done it correctly? Engine must be idling and ATF at a precise temperature to pull the dipstick or remove the overfill plug(sealed trans) for accurate reading. You can read your ATF temp with a scan tool or using the obd2 connector pins method( just google tundra atf level check procedure). Be sure to use the correct info for your transmission (A760f for 4.6l 4wd, A760e for 4.6l 2Wd, AB60f for 5.7 4wd or AB60e for 5.7 2wd).

 

Oh yeah!

the 1st few things I’d say about that is

a) the symptom
Occurred after Toyota flushed it.
So they would leave it low??

2ndly. Yes. After I replaced the fluid in the pan, I jumped the pins on the obd thing underneath the dash, waited till it got up to temp, pulled the check plug, and got a fine steady bead of fluid.
Funny thing is I changed my dad’s fluid on his 2020 tundra, and from what I observed (because after draining fluid, I measure how much came out) Toyota over filled his truck. There was about an extra half a quart of fluid in the transmission.

I will put it in to test mode again this week and pull the plug and let you know the result. Do just double check I’m not crazy

 

Let us know your results when done!

 

High mileage and towing - I'd be looking at worn frictions pack.

Add any transmission shudder fix product and see how it goes in a couple of days.