Rumble Feel after Wrong Transmission Fluid

My truck: 2015 DBC TRD OR with 130k miles.

I recently had my transmission fluid drained and refilled and (I later found out) the shop put the wrong fluid in it (not WS).

It drove fine for a week but when I took it up a winding mountain road I began getting random power loss, power steering loss (got loose not tight), and hearing a clunking sound. It sounded and felt like I was driving over a rumple strip. Feels like the pedal goes to the floor but there's no increase in RPM's, there's a quick decrease. Whole thing lasts about 2 seconds, then goes right back to cruising along happily.

It only happened on the winding mountain road.

I did some digging and figured out they put the wrong fluid in. I took it to a different shop and did another drain and fill with WS transmission fluid.

Truck drives and shifts fine...until I went on the exact same winding mountain road about a month later.

It's been about a week and I went on a different winding mountain road that was less aggressive (paved, not off road), and it happened once today.

Any thoughts on this? I'm inclined to have a full flush and new-new-new fluid at this point.

I did find this thread but I'm not convinced we have the same issue:

https://www.tacomaworld.com/threads/rumble-strip-sound-feel.653432/

 

I don't recommend trans flushes ever. Drain and fill. Valvoline maxlife atf or Toyota ws.

 

I appreciate the arguments against doing a full flush, but in my position I'm inclined to purge all the non-WS fluid from the transmission.

I'm asking because I'd prefer NOT to flush it, but I'm not 100% sure the transmission is the problem. Everything I'm reading is pointing to it, though so I figured I'd ask people smarterer than me.

 

I think the transmission holds something like 12 quarts total. A drain/fill would typically be 4 quarts? Because of dilution, you would need to do 8 drain/fills to get to 93% new fluid. There is a strong possibility that there is a lot of incorrect fluid still in the transmission.

Also, Did you confirm the correct fluid level? Transmission at the correct temperature window and checking the fill level drain?

 

During the first (wrong) fluid change I checked the transmission fluid at operating temps and it was low. I didn't check it after the second drain/fill.

You're right about the 12 quarts vs. 4 quarts, and that's why I'm leaning towards just doing a flush.

 

I did a flush at 150k for the first time, it’s a risk because it clears out anything that could be holding your trans together if the fluid is original. I would do it just because new toyota fluid is better than having some random fluid that’s causing you problems. Any idea if your dealership is any good? The closed transmission is more niche to flush that’s why I opted for the dealership.
(My taco shifts so much smoother now and I made sure to double check the level when I got home because you can never be too safe)
Good luck resolving this

 

Thanks! That's kind of where I'm at. I had the fluid changed (drain/fill) at 100k, and I get the gripes against a full flush. From where I'm sitting it's the obvious solution.

I am planning on having the dealership do it. I figured I'm two shops in and might as well pay to have the folks that do this everyday fix it right.

 

Do you have a scan gauge or something to monitor trans temps? The heat from driving mountain roads puts stress on the trans and the wrong fluid may be exacerbating that.
Keep us updated

 

I've got the Scan Gauge 3 in my Amzn cart. Definitely on my list. Having said that, I grew up in the mountains, driving winding roads every day. I understand the stresses it puts on transmissions.

That wasn't what I was dealing with. This was like 1 mile into the drive, empty, not towing, not going fast. And I've driven that road a dozen times prior to this happening without issue. It's a new problem. And the only thing that's changed was the (wrong) fluid.

 

Drop and clean the pan out, a new filter. You'll get almost 6 quarts out that way. Stick with the WS, I've fixed more than a few early symptom TCC shudder vehicles with a pan drop, then a drain or two.

 

Good to get it flushed. I have a 07 4.0 and the dealership told me that I didn’t need to worry about my transmission cause it’s sealed no dip stick. At 190,000 I had to have my transmission replaced and was told that I probably wouldn’t have needed to do it if I would have had my transmission fluid changed at 100,000. It cost me $5,000 for a Toyota crate rebuilt from Toyota

 

If you need the proper trans fluid in a certain trans, then you need the proper fluid.

You can probably achieve this by doing two replacements.
Even just one replacement is usually not bad. If a car has 7/10 of what it’s supposed to have and 3/10 of what it’s not supposed to have, it’s generally fine.

I work on cars for a living for a long time and have never heard of or seen someone doing a flush.

I have seen Jiffy Lube claim to do certain work on a friends vehicle and not actually do said work.

depends on if you have a TQ drain plug.

 

I see no one asked this question: What speed were you going when it happens?

 

I havent seen wrong fluid cause a shudder like this, we have a WS flush machine and I would use it in this case but make sure if you decide to use a shop to flush it, that the machine is normally using the correct fluid.

Something seems off, I'd almost go to a dealer at this point, they only have WS so there's no messing around.

 

Good question! It happened going fast or slow (30-60), up or down, left turn right turn and straight, on the gas or off the gas. It's totally random.

 

I actually called the Toyota dealership today and they said they don't have the equipment to do a flush, but for the low-low price of $500 they could have a tech look at it to diagnose the issue.

It's certainly a weird problem and tough to describe accurately. The reason I posted here is because I'm leaning towards the bad fluid, because of the timing of the problem and I've read some similar symptoms with too much/too little fluid. Just trying to see if someone has had this problem before and I'm way off on the cause.

 

You should just confirm it’s at the proper level with the temp.check method. Shops are not always correct and don’t know these vehicles need to be check at proper temp. Mine was low from factory by 3/4 qts. and I would have a little slip on cold mornings when starting out. You are describing a situation of fluid starvation due to low fluid and out of level fluid in pan, due to road grade and fluid sloshing around.
There is a correct procedure to fill these transmissions and if it’s done like other vehicles it can create a problem. It needs to be confirmed by temp.

 

We have BG trans fluid here where i work..(just for an example)..I flushed my 2009 with the BG fluid,its compatible with WS fluid.Never felt any Shudder before..and On the drive home i noticed it had a small shudder that got progressively worse at a slower speed the more i drove it..a couple days later i flushed it with WS and it was smooth as glass again.

 

This.
For real though. So I tried the Aisin WS and it isn’t as good as Toyota. slower shifts and holding gear longer. Put some more Toyota back in and all was good. I did the max life on my Jeep Patriot with the 6 speed Hyundai transmission and that requires SP4/SP4M atf. Amazing how you can run the same fluid for the Hyundai and the Toyota but not the opposite for SP4 vs WS in either application. I am tempted to see how mixing fluids would affect the viscosity. If you accidentally put a higher viscosity ATF in your transmission (than OEM specs) then would you able to balance it out by draining some and then adding a lower viscosity fluid than OEM?
Or are the base oils different where it would cause issues with shifting or affect the seals? Compared to the OEM. I would assume if it’s the same supplier with the two fluids then you could mix them.

 

The first drain and fill resulted in a low level at temp (checked about two weeks afterwards). What you're describing is exactly what I was picturing in my mind, though I'm also bugged by the correct fluid not being in there.