2007 Tundra 3-4 shift

All, I have a 2007 Tundra, 5.7 with 251k miles. I've owned the truck since it had 50K miles and, as far as I know, the transmission has never been serviced. I've noticed lately that, when the truck is cold, the first 3-4 shift is a bit late. If I happen to accelerate a little harder, it will hesitate and slip a bit before it shifts. After that, the transmission seems to work perfectly.

All in all, not all that bad. But I'd like to try and fix it if possible before it gets much worse and the slipping starts doing more damage. I am unsure what the typical life of these transmissions are and I realize the end may be near for it.

Any advice on this would be appreciated.

Dana

 

First drain and fill, alot of people drink the lifetime fluid, as I did, and don't change it until this happens. After this change your fluid every 20k miles. Either Toyota WS or any other similar or superior lubricant you feel comfortable with. I'm at 310k, owned it from the start and have started the maintenance schedule since 270k, dropped the pan twice due to sensors going bad, so I've technically cleared 14 quarts between bothnof those times.

 

Cold shifts will be less than ideal in most auto transmissions. The fluid needs to be warm for optimal performance. If you've never refreshed the factory fluid in there it is also likely low on friction modifiers that make the fluid work better. Do as @blackdemon_tt suggested and do a few spaced out drain and fills with Toyota WS fluid. One of the few additives I've come across that actually works (even cures GM 8 speed transmission shudder) is LubeGard Platinum transmission additive. I use it in all my auto transmissions now and it truly makes the transmission shift smoother and with less lagging. I'm still on my original 4 speed auto in my 2000 Tundra and it shifts like new. I tow heavy too, so I haven't been easy on it.

 

So to be clear, drain and fill only. No filter change. Also, approximately how much fluid should I purchase?

 

4-5 qts is usually plenty for a drain and fill. If you can find a better deal in bulk, get enough for a few drain and fills at once. Do a drain and fill with each of your next few oil changes.

 

What @KNABORES stated. Pinning the transmission cooler gets you about 4.5 quarts, unpinned it's about 3.5 quarts.
I will agree that filter change is not necessary. Plus dropping that pan will be no fun since some bolts may snap.