2016 121,000 miles needs new transmission

Recently I knocked the rear axle out by hitting one of the little "U" poles next to a gas pump.

Axle replaced (along with surrounding parts) Reputable garage, I trust them.

I get the truck back and about 2 weeks of normal driving it slammed into gear one morning. Check engine light and "Traction control off" on the dash.

It drives fine, but when the the motor is cold it doesn't shift out of 4th on it's own. I release the gas and it shifts. Once it's warmed up it drives normal. (Drove like this for about a month)

I take it back and they tell me it's not related to the original issue. I'm not mechanically literate to intelligently argue about it.

Does this seem right?

 

What were the codes when the dash lit up? Are you sure it shifted into higher gears when cold previously? Mine won’t shift into higher gears when cold either, (not sure if it holds in 4th or 5th) until a mile or two down the road. I assume it’s tuned this way as not to lug a cold engine.

 

Never touched it.

 

Definitely shifted before; like night and day.
I didn't get the codes.

 

Is it 2wd? Is so, and if the driveshaft was removed from the transmission at any point during the repair or for towing, you very well might have low transmission fluid.

 

It is 2WD. I will bring that up to them, thanks.

 

Not sure if it will help, but you could always try to disconnect the battery for a bit and let everything reset and relearn. As mentioned above, make sure the fluid level is right. Highly doubt it is related to your wheel catching the post.

 

Yeah 2nd resetting the tranny and checking the tranny fluid making sure you have enough.

 

Would def check trans fluid level yourself. Lots of info posted on site. Some shops are not aware of how to check or set proper level.

 

What does a transmission service include?

 

Drain and fill.

 

After service was done now it's worse.
insurance is saying they don't know this was caused by the incident; and they need to open the transmission to find more info which I would be responsible for in the event they do not cover the replacement.
They are doing more "Research"...

 

It’s very possible that something internal got damaged when the axle was damaged. Not sure how fast you were going or which direction but if it was hard enough to take the axle out then the shock could have gone right up the driveshaft into the transmission.

 

There is a chance of damaged internals in the rear differential. Somewhere on here, I read that a rear gear was cracked from an impact. Maybe something going on in there causing the tranny to respond in a strange manner. Not likely, but I think it might be worth jacking it up and throw it in neutral, then manually spin the tires and see if all rotates in a relatively smooth manner in both directions. Just a way to try and narrow it down a bit. Another option would be to change the rear differential oil and see if any metallic shavings or chunks appear in the old oil. Be honest with us and tell us more about the collision too. Did it hit hard and knock you around a little bit inside the cab?

Edit: oops! Forgot to read your OP again!

 

Apparently the thing took a big enough wallop to need a new rear axle. Definitely enough to damage the transmission. I have zero doubt now.

 

Maybe it's just me, but I'm struggling to picture what a little "U" pole next to a gas pump looks like, and how hitting one knocks the axle out.

 

Thinking something like these, not turning wide enough, and the Tundra was in a desperate hurry for a drink??

 

Aye aye. But I'm still struggling to get my head around the angle, not to mention the speed, at which one must be going to collect with this to cause this sort of issue.

 

If the rear axle was forced forward, I could see the driveshaft yoke running out of clearance and damaging the transmission internals. If the axle was forced backward, then not sure how it could have damaged the transmission.

 

That's what I imagined but in my mind's eye the pump was displaying Nascar logos...
I wonder just how much forward progress was required to upset the axle in an area that isn't exactly suited to boy racer stunts?...

 

Damn this almost happened to me too one early morning before coffee, but my sliders kickout saved me and instantly paid for itself. Sorry for the troubles OP.

 

Maybe the OP can clarify what exactly happened here.

What I'm picturing is: pulls in to get gas, when done, can't exit forward and so decides to back up (the direction of travel of the arrow here), and so cranks the steering wheel and somehow or other the rear wheel got snagged up on the bollard, e.g.

These bollards are pretty clearly blue Loctite'd in place, thank god they did not use red.

 

I Imagine the assembly was in rotation with a significant amount of torque going through it and then an instant sudden complete stop occurred at which time there is a chance that even more force was applied to the skinny pedal momentarily...not good and likely the cause for improper transmission function.

 

Struggling to see how even rear axle damage occurred with this scenario unless it was at speeds above 30 mph which is nuts.

given service history it is likely a valve body solenoid that is sticky.

I've had cold shifting that was super harsh even when truck was new. I also have seen shift strategy change when ambients are below 40 deg F.