Firmer shifts after pan drain and fill

So I’m fairy new to Tundras but not Toyota Trucks. I have owned several 1st and 2nd gen Tacoma’s over the last 15 years but due to a growing family I had to upgrade to a larger truck that was capable of carrying 3 car seats. I ran across a 2007 crewmax (1 owner 125k miles) in awesome shape that was in my price range. I ended up purchasing it after an extended two day test drive (to make sure it met my expectations). With me being a service freak the first thing I wanted to do was catch up on the unknown service history. Per Carfax it had great oil change intervals but really no other serving had been performed.

After a complete tune up I wanted to start getting all the original WS fluid out by doing a couple of pan drain and refills. I ended up going with Valvoline maxlife due to me having great success many many times with my Tacoma’s Aisin a750f. The first drain went unremarkable, a week later I did another drain with maxlife and soon noticed a “much firmer” shift in almost all the gears. To the point that my wife noticed. It also had a pretty aggressive downshift that it did not have befor when coming to a stop. Well my thought was maybe the ab60 is more sensitive to fluid change than my Tacoma and didn’t like the change in viscosity, So I ordered some oem Toyota ws. While waiting two days for the fluid to come in I noticed almost all the hard shifts went away except the 3rd to 4th shift. Which is still present. I did a third drain with ws and a fourth with ws and still no changes. I know 100 percent the fluid level is correct.

at this point I’m not sure what to do. Maybe have the dealer reboot my trans memory? Over on Tacoma world I follow a lot of very smart transmission experts and some have stated possible glazing on the disk. I put in 12oz of lubegard platinum but with no effects. Anyone want to add your two cents???

 

My old truck of 7 years. My new truck of 1,000 miles

 

I may want to mention that I’m sure this truck has had a very easy life with little to no towing. The original transmission fluid was dark but still red in color and still smelled good. Definitely not abused or mistreated. The tow package had moss growing in the hole so I suspect it has been quite some time since it pulled a trailer or even had a ball hooked up.

 

Try dumping a tube of this stuff in. I've heard mechanics rave about it & it's helped me out with a tranny issue.

https://www.amazon.com/gp/product/B0002JMLQU/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

 

I have thought about it. I know a TON of folks over on Tacoma world love lubegard and use it religiously.

 

Did you perform the fluid level check after each drain and fill? If your fluid level is off even the smallest amount, your trans will shift weird.

This is one reason I prefer a full fluid exchange.

Does the Valvoline meet all WS specs?

I wouldn’t add anything to the tranny unless you are at a point of no return. Ex. You’ve ensured fluid level is correct and I would check the pan.

I’ve exchanged many Toyota sealed transmissions (I use amsoil) and never had problems you mentioned as long as the fluid comes out looking good and the fluid level was correct after. Hopefully we can help you sort through this.

 

Yes I verified it by jumping the obd ports and also on my Ultragauge. BTW my 2007 goes into temp check mode at 99 degree and not the 115 that most of the info is showing.

as far as the Valvoline meeting the ws specs... it says it does and I also done a lot of research as well. The numbers are very close to ws viscosity.

 

Since a lot of people havegreat outcomes with AMSOIL fuel efficient. I compared the specs of maxlife vs AMSOIL vs WS

Cst at 100c
WS 6.0
AMSOIL 6.0
ML 5.91

Cst at 40c
WS 25.0
AMSOIL 29.8
ML 28.82

viscosity index
WS 201
AMSOIL 153
ML 156

Brookfield viscosity
WS unknown
AMSOIL 9050
ML 10200


So In theory ML and AMSOIL appear to have very similar chemical makeup. (unsure about anti wear properties but viscosity values). I know a lot of people don’t like ML due to it being a universalproduct. Since AMSOIL don’t list as much compatible make and models I feel that both are a great alternative eventhough they don’t match the WS numbers perfectly.

 

The only thing I have not done is drop the pan, but I would suspect that to be unremarkable and a waste of 6 quarts of fluid.

 

Are you sure it's the transmission? Might be barking up the wrong tree. I found it odd in the Tundra that slip yoke is not greaseable as my 4runner was. You must pull the driveshaft, unclamp the boot, clean and grease it, and then reassemble. I haven't done it yet but that's what I have always attributed the occasionally clunky feeling shifting to. Others would consider it normal and say I'm just being too picky.

 

I did a drain and fill on mine back in 2017, when I had ~120k miles. It looked like it had never been changed, was mildly dark, and didn’t smell burnt (truck was also in great shape, never beat on). Filled it back up Toyota WS fluid, and after that I would occasionally get a jolt when 5th gear torque converter lock-up engages. It only does it while cold, and not often enough for me to try and fix it.

YMMV, but I’ve learned my lesson; and won’t ever change transmission fluid unless I know it has been done consistently before I took ownership.

 

I feel ya! That was part of my 5k regimen when I had my Tacoma. Grease my Zerks and drop my drive shaft at the carrier bearing to slide my yoke out and grease it while my oil was draining. With the tundra it does not have Zerks but rather a triple seal non serviceable spicer.

 

One weird thing I noticed is that these transmission run about 50-60 degree hotter than the little brother a750.

 

interesting data! Mine seems to not do it until over 120 degree. Also it does not do it if I’m more aggressive on the throttle and make it shift around 2500 rpms. Zero slipping or delays though

 

Very interesting, indeed. Because mine does it when I try to make it shift by letting off the throttle (only 5th gear, though). I’m suspecting a sticking solenoid. But my knowledge on transmissions is pretty limited.

 

Why not drop the pan, replace the filter, refil and see if that helps? it wouldn't hurt, well except your wallet but worth a shot. I noticed my tundra would occasionally feel like if I was driving over the safety grooves on the side of the road while riding between 45-65. I did a full fluid exchange about a year ago, never happened again after that. A750F's can be fussy. I know my problem it is not exactly what your is but one never know, that might fix the issue. my 0.02

 

thanks for the input! Seems like we are in the same thought process. I picked up a filter and some fresh fluid today. Gone give a last resort flush tomorrow and see what happens.

 

Swapping the screen/filter would be a good move. I use BG’s ATC p/n 310. It’s has smoothed out a lot of transmissions for me. Did you pin the cooler when checking your fluid levels? It sounds almost like you’re low on fluid.

 

Yeah it was pinned. I’m most certain the fluid level is correct. Although that would be an easy fix!

 

i haved maxlife in mine with no issues. getting close to 250K , let us know what you find

 

Great thinking!!! I have owned toyotas all my life, and there is one rule I have when it comes to doing maintenance or repairs to my trucks/cars, use only OEM parts and OEM recommend fluids, (don't ask me how I learned that) Yes they can be pricey but I believe in the long run sticking to that personal rule has saved me tons of money. Whenever a friend buys a used Toyota we always get together and replace ALL fluids right away, including coolant; that way he knows exactly when fluids need to be replenished or replaced, no guessing. Anyhow Good luck with your tranny, and keep us posted on the results.

 

I believe you are taking the right action. Everything I've read says MaxLife ATF works fine in all Toyota transmissions, but I am a little skeptical of mixing the two fluids together with a drain and replace procedure. A full fluid exchange of either fluid will probably restore your transmission to prior performance levels. I'll be watching for your results.

 

I encountered the same issue with my wife’s 08 Sequoia which uses the same drivetrain

I filled with an additional 1/2 quart of fluid AFTER performing the level check

It’s been fine since

Oh,and I also use the Maxlife without issues in all my Toyota vehicles

 

Well I got a brand new filter with 12 brand new courts of ws. The filter looked pretty clean for 125k miles. Took it for a test drive and the 3rd to 4th is still pretty stiff. So I’m gone give it a few more days/weeks and see if it smooths out.

 

Have you tried adding this? There was a transmission builder on tacomaworld that always recommend this stuff.
I personally used it in my problematic Honda auto trans and it fixed a lot of the issues I was having. Also recently started using it with my 4runner V8 with the a750f with 200k miles.

 

It might take another pint more if you didn't get every drop of the 12 quarts

 

Yeah I been running 13 ounces of the lubegard platinum for the past two weeks. Not much if any change. I think it may be a slightly worn valve body seal that is causing it.i think my computer is sending a slight low pressure and sending more fluid to the valve. I can rebuild the valve body myself for about 220$ with a zip kit and I’m sure that would fix it since noting else has.

 

Everything looks good and clean, if the problem persists my next stop would be at a transmission specialized shop to check and test the whole transmission. Sometimes the control units inside the gear box need to be reset to factory specifications and then "it" needs to "re-learn" the best and most optimal time to switch gears, a bit extreme move but based on everything you've done, specially after replacing all fluid you should feel improvement. Did you check the fluid level after you were done?

 

Add 1/2-1 more quart fluid and see if there’s a change.

If not you can always cycle it out next drain/fill

 

tech stream may be an option as well. I’m curious about them deleting the memory and doing the relearn...but I don’t want to pay 105 dollars for them to do it! I’m trying to find someone local that may can down load the free version.

also yes the level is correct. I’m pretty good with the procedure. I done many many pan drains on my past Tacoma’s over the years and also on my dads Tacoma. All with no bad outcomes. That is why i still in Denial about me messing up my new truck!