mikob

So immediately after I flushed and filled my transmission fluid on my '90 LS400, I realized I filled it too much. So I got back under and flushed until the proper level. The transmission went from perfect to abysmal instantly.

Now I'm getting these symptoms:
*Takes a long time for gear to engage, car wont move in drive or reverse occasionally (esp. in cold weather)
*Gear engages but car moves really slowly until warmed up (even at high rpms)
*Gears engage/disengage when in drive but idling (I have to keep my foot on the brake, it jolts forward when the gear engages!)
*Car stalled when idling once

I've heard the transmissions are rock solid on these. I've read that the solenoid seals sometimes rupture and the solenoids start to fail. Could this be my issue? Unfortunately no OBD on this old beast, so I can't check for solenoid codes.

sam12345

iTrader: (1)

Most likely the new fluid loosened dirt and clogged your tranny or gumed up your solenoids. Drop the pan, clean the solenoids and change your filter. You may want to add an inline filter. If your car has 180k you may want to change your on off solenoids. The on off seats wear over time and the first symptoms are harder than usual shifts at part throttle but it is not a sudden change like you experienced.

Yamae

Your symptom sounds like the condition when the ATF level is too low. How did you check the level? You need to check it when the engine is idling and the shift position is in P after throughly engaging all gears. I hope you didn't check the level as you did the engine oil stopping the engine.

sam12345

iTrader: (1)

Good point never thought that he may have checked it wrong. It should also be fully warmed up. At least driven 10 miles before checking. Also if you just put tranny fluid in it will show like it's too full because it's still in the tube. Drive three miles between each fluid addition or u will get a too full reading due to the fluid still in the pipe the dip stick goes into.

dicer

At least in the Gen 1 when you drain the fluid its only 2 quarts that come out. Just put 2 back in. It is really difficult to read the dip stick, as fluid in the tube (on the walls of it after adding or constantly jabbing the dipstick) can give an erroneous reading.

Also what brand fluid did you use?

mikob

I used Dexron VI which states it's Toyota T-IV compatible. The dirt theory is very probable as before I got the car, it had been sitting for many years without a fluid change. I had to drive it a bit on only partially-flushed fluid (as not all of the transmission fluid comes out in a flush).

I did follow the instructions in checking while the car is running and only after driving and shifting through all the gears. But I suppose there could be oil on the walls too. No idea how to measure correctly in that case, don't know how much I took out, or put back in. I tried adding more and more in when I started experiencing symptoms, doesn't seem to have an effect.

Car has 115k, but was sitting for many years. So, solenoids is improbable?

sam12345

iTrader: (1)

Yes dirty/worn solenoid is probable. Most likely dirty

dicer

And maybe it wasn't very compatible ? Did problems start after adding it?

mikob

Problems did start after flushing and adding this fluid. But this oil says right on the bottle that it's compatible.

I checked the level again today after driving around, shifting through all the gears. It was perfectly 50% up the hot section. I'll put some more fluid in tomorrow, see if there's even a noticeable difference.

I suppose clogged filter is even a more likely issue? If the symptoms are characteristic of low oil, maybe the oil isn't getting to the right places because of the clogged filter. The oil I swapped out was REALLY old. The solenoids are a bit pricey if I'm just buying all four. I'm thinking of doing just the filter, trying it out, then ordering the solenoids only if the new filter doesn't fix the issue.

cobalt91

What did you use to flush it?

sam12345

iTrader: (1)

Clean the solenoids while you have the pan off. Probability is it's the solenoids dirty. Your mileage is a bit low to be filter. So clean thenm out

Yamae

What do you mean by "50% up the hot section"?
Do you mean that the level is just the half level of the hot zone? If so, add till the top of the hot zone when ATF is warm. Sorry that English is only my third language and I'm not good at it.

I drive a 98 Celsior. This is my actual experience and this may be useful for you to know the character of this Aisin's AT.

When I filled the ATF Toyota type IV up to the center of the hot zone, I had similar problems as you mentioned. I added some more ( about 0.5L= a half qt+) and it was mostly OK but it was not fully OK when very cold.

So I added some more (can't remember how much precisely) and the AT worked perfectly. It was a few mm ( 1/10 inch) higher than the top hot zone. I dare kept that level now since I drained some to be a bit less than the top level and this caused a slow shifting problem when very cold again. What I think is that the best level is the high end or even slightly higher than that and I added some more. It has been more than 28 months after that and the AT has been working perfectly.

dicer

I went to the Toyota dealer today to get some IV, he first grabbed some dexron, I said its supposed to be IV. So if Dexron was compatible like mentioned above then why does the dealer have both types available? And both have Toyota on the bottles.

Hmmm I'll try to answer my question:
Because the IV is going to have a different formula of friction modifiers, and since seals and friction material has run in that and soaked in it, adding something else may have something that could chemically attack those items. If you do a complete transmission rebuild, then using a compatible fluid would be just fine, just keep using it till the next rebuild. Mixing fluid types is not a good idea.

paulo57509

I don't know what brand of Dexron-VI you're using but the labels on the containers of Valvoline Dexron-VI in my stash don't say that it's compatible with T-IV.

Your A340E transmission specs T-II which isn't made anymore. T-IV is backward compatible with T-II so T-IV is what you should be using, IMO.

This is the only other stuff that I have found equivalent to T-IV:
http://www.avlube.com/mobilatf3309.html

The reason why the Toyota dealer has both T-IV and Dexron is that older Toyotas specified Dexron. My '87 Camry transaxle was spec'ed for Dexron-II.

Another reason is that some Toyota P/S systems (my '98 LS400 included) also specify Dexron.

dicer

Yes for the Dexron on older stuff. But what I was driving at is if Dexron was okay then there would be no reason for the DEALER to have the IV on the self or in the store period. SO THERE IS A REASON TO USE THE IV TYPE FLUID. Its so funny there are so many threads on using the RIGHT STUFF, yet people use the WRONG STUFF then complain about a transmission problem.
And really are you saving a buck doing the wrong thing?