High mileage Tundra downshifts unexpectedly, indicator lights on

I have owned my 2008 Tundra CrewMax Limited 4WD since new. It now has 271,000 miles on it. I had the transmission fluid changed at 183,000 miles. Last Wednesday while driving it on the highway at about 60 mph, it downshifted into 4th and stayed there. Normally at 60 mph, the tachometer is reading 2000 rpm's. When it downshifted, the rpm's jumped to 3500. I could not manually shift it into 5th or 6th. No indicator lights came on at this time. I made it home and shut it off. A little while later I started it up and had four indicator lights come on. 4Lo and VSC off flashing, Check engine and slip indicator lights on steady. I have an appointment with a mechanic next Tuesday, but was wondering if anyone else has seen this. Thank you.

 

I had the identical thing happen on my '07 this spring. Get it scanned and check for codes. Mine was a S4 shift solenoid (code was resistance high), dropped the pan, replaced with a new solenoid, and all has been well for 5,000 miles.

 

Thank you VWTim, I will let you know how it all works out.

 

VWTim - It was exactly what you said it would be. I had a shop replace the S4 shift solenoid and that took care of the problem. Also discovered a bad front wheel bearing while it was on the lift. Had both front wheel bearings replaced, so it was in the shop a little longer than anticipated. Running great now. Thanks for your help.

 

Same here with the 2007 and the AB60F transmission.

 

Glad you got it fixed!

 

Were your transmission bolts all rusted? I'm debating whether or not to do this job myself because I feel it will be quite expensive to have done by a shop.

 

Not all of the transmission pan bolts were rusted. Two did break off while they were being removed. The mechanic had to drill them out and replace them with a bolt and nut. I opted for a repair shop because they had a lift. All I have is four jackstands and a gravel driveway. Hope this helps.

 

Fwiw, all of my bolts came out like nothing. Granted I have a PNW truck so very little rust and zero salt exposure. '07 with 165K

 

my 08 with 240k is rusty on the bolts. Took to toyota dealership, they broke 1 of the bolts and said they could attempt the others but drilling out would be expensive and if they couldn't get out, new tranny.

I spent nearly $500 for them to break a bolt, never repaired it or even replaced the bolt, and to change the fluid

 

I'm terrified too because I've got 256k miles and I don't think the fluid's been changed for the past 150k miles or 12 years! My dad was the previous owner and said he never even touched any of the differential's or transmission and now I'm stuck with the consequences. And I know my local toyota dealership could care less just like yours did so I'm really debating on biting the pain bullet and doing it myself but I don't have a lift and I'm sharing my 1 car garage and driveway with 5 other cars atm.

 

I've said this here before, but my local dealership tells me they do a fluid extract/fill through the fill plug in our transmissions. Never touching the drain. I then asked about the filter/element change and they said they only recommend that if the fluid condition warrants it. Quoted $250-300 for the fluid exchange.

 

On a system with as many miles as mine going unchanged for as long as it has it's gonna need the whole works either way. Taking the whole thing apart would just add to peace of mind for me personally because I'd know if there isn't any chunks of metal sitting in my pan that I wouldn't ever know about if all I did was flush the system through the fill plug...