Beating a dead horse (transmission fluid)

Could not having the transmission fluid changed cause gas mileage drop 110 mpg

 

Wait ...what?

 

Unlikely that changing or not changing the transmission fluid would have ANY effect on miles/gallon.

 

I'm curious because I have no clue how I went from 330 miles to a tank to 211 miles to a tank

 

Prob one of them masked ninja from that weather tech commercials slipped some larger gears into your tranny while it was parked at a Chevy stealership???

 

MPGs = miles per gallon. I think you are referring to MPTs or miles per tank and no dirty t fluid will not cause a drop

 

I asked him in another thread if he was hand calculating but I never got an answer. I never trust the readout on miles per tank. I just know that I can do about 200 in the city and about 320 on the highway.

 

I never calculated it I always use trip A and I has been good enough for me either way I used to get 280 city and 350 highway and now I don't so there is a problem somewhere. I'm asking questions because that's what the forum is for.

 

You should still hand calculate. Super easy and way more accurate than filling up at a quarter tank and assuming it should’ve lasted you longer.

 

I wasn’t trying to poke a dig at you. And you can ask as many questions as you want never said you couldn’t. But if you’re going to ask questions we are going to ask questions back to clarify. Miles per tank is not as accurate as miles per gallon. I understand you used to be able to go further on a tank of fuel. Since you are using Trip A and resetting after each fuel up, just divide the miles you went by the gallons you put in. Miles per tank is too vague. But I’m not saying I don’t believe that you are getting poor mileage. Maybe your four-wheel-drive isn’t completely disengaging. Check the front of your truck up and spin the wheels. This should show you if they are spinning freely or if there is resistance or it’s straight up in four-wheel-drive.

 

There is resistance when I spin the front wheels but the front drive shaft spins freely unless it's in the front diff

 

Hmm I can’t remember how the front differential works. Is there an actuator in there that locks and unlocks the hubs? It would be great if it’s as simple as an actuator and doesn’t involve a differential replacement or rebuild. Maybe a good time to change the fluid and see how it all looks.

 

@Woodtickmp https://parts.toyotaofcoolsprings.c...cat/differential-scat/?part_number=4140034020
So there is an actuator. Number 13 on this list in the link. I wonder if it’s hung up and staying engaged.

 

It was almost out of fluid in November and I filled it. Every now and again it locks in rough and unlocks rough but it's not all the time

 

Is it leaking? It shouldn’t be low unless the previous person who serviced it didn’t add enough.

 

It was my father-in-laws truck and he took good care of it and there are no leaks but there is an actuator that engages the front diff I wonder if it is not dissengaging all the way

 

Maybe it’s possible that it was ran for too long with low oil and things went south inside.
Did you refill it with the recommended oil? Maybe it’s due for a fresh change out.

 

Make sure you don't have a caliber that is hanging up.

 

Maybe I'm off base or common opinion has changed but I've been told and have read a number of times that mechanical transmission flushes were a bad idea because there is a possibility that the force of the flush could knock something loose and then that gunk can get jammed into some other crevice within the tranny causing a premature failure? Supposedly this has happened more then once but usually with transmissions there weren't regularly serviced and were flushed for the first time with 150+k already on the tranny?

IDK, maybe that's all BS but I've always been leary of transmission flushes?

I get with some tranny's (like the one in my 4th gen 4runner that is sealed) there really isn't any great options but with the Tundra, what's the problem with doing it old school and dropping the trans pan and replacing the filter? I know you don't get all the old oil that way but you don't get all the old oil out doing a standard engine oil change either. The offset is, you get a new filter which is probably more beneficial then getting out every last drop of old oil?

 

I did use recommended oil when I filled it but it looks burnt

 

They are hoping to sell you (or a future owner) a new transmission at 100-150K miles....

I wish the truck had a dipstick, but the fill port is fine. I'll to a full fluid change at 60K miles. Always have on AT's. Does this AT have a changeable filter? One thing I loved on my wife's Subaru was the external screw on oil filter. After Warranty is over, I may add an inline screw on in my AT cooling lines.

 

Yes, it does, but the pan bolts are subject to snapping off during pan removal to change the strainer. Pan bolts snapping off during removal is less likely in areas with low corrosion, more likely in areas where the environment is wet and salty. The fact that Toyota calls it a "strainer" in the parts catalog indicates that it will only remove the big particles; it's nothing like the micron rating of an oil filter.