Overfilling The Transmission - Possible Damage?

[K9crew]

I'm unhappy with the way that my LS shifts so I started looking through the original owner's service records. He had a similar complaint and the service description is "checked and adjusted ATF". I've had the car for a few months and I knew that Lexus "changed" the ATF at 45K miles (2 QTS. that is) so I didn't bother to check the level when I bought the car ... I did check the color/condition. Since I'm unhappy with the way the transmission is shifting I checked the ATF tonight when the car was cold. I checked it on level ground with the engine running and I moved the shift lever through the gears pausing in each gear for about 5 seconds. The COLD level was just below the HOT mark on the dipstick. I drove home (about 15 miles on the freeway) and stopped at a gas station near my house to check the ATF while hot. It was difficult to determine how much the fluid was over the HOT mark because it's hard to see the fluid on the thin wire part of the dipstick. My guess is that it's at least 1/2" above the HOT mark. So now to my question, will an overfilled transmission result in damage and is it reasonable to expect the shifting to be affected by overfilling? I plan to drain the trans pan (2 QTS.) first thing in the morning and only replace 1 QT of Type 4 ATF. I'll check the level COLD and take a quart of ATF to work with me and check the fluid once I get to work.

Thanks for any help.

:)

[99lsguy]

k9,

I don't know if it can damage it or not. I suppose it depends on the Duration of long trips that may cause the fluid to "foam". I do know the fluid does expand a little when HOT. T-IV has "foaming inhibitors" and synthetic additives; it is good product!

I changed my ATF first thing when I got the car and know what you mean. Mine was "slightly" overfilled - probably to the top edge of the upper blub marker. (you know - right where the top tapers into the cable). I think you should let the car warm up a little bit just to get the fluid warm before you pan drain it.

My 1st pan drain got nearly 3 quarts out! So I put back in 2.5 and made a run. Well, the fluid was still over the full line, but barely! This kinda makes me think that the older the fluid is, the more it expands. So I'm thinking the stuff in the torque converter is actually "overexpanded" maybe 1/2 quart - that's why it was too much.

Anyway- drained it again next weekend and out came 2 .5 quarts or so - I then refilled it with only 1.5 quart. Then took a run - I believe the whole system needs to be HOT to get accurate reading on the upper section of the dipstick. This time I was about in the middle of the "HOT" section. Then I VERY CAREFULLY added just 2 oz or so. THERE IS VERY LITTLE RANGE between the ADD (hot) line to the FULL (hot) marker. So SLOWLY sneak up on it. It it this kind of procedure alone that we as DIY owners pay MUCH MORE attention too than any tech would.

All this being said, I can't be sure if the car shifts any better - as it was always smooth. I do know the tranny is better off not overfilled!

I know I feel better about it. And to be quite honest, I don't think a Lexus service tech would do as accurate job as I have done.

99

[99lsguy]

k9,

BTW,

Lexus dealer can read the OBDII codes to check for High Temp or any problems triggered by the shift solenoids - for peace of mind. Here in KC its about $50 for the diagnostic.

Our cars have 6 yr / 70,000 mile drivetrain warranty so they should cover any faulty solenoids or other. I'd like to be there if they agree to drop the pan and look at the screen, magnets, etc.....

[wwest]

Over-filling will lead to the fluid being stirred/whipped and foaming will occur and there is no doubt that will affect the shifting points/functionality but likely no long term harm.

[K9crew]

My 1st pan drain got nearly 3 quarts out!

99,

I drained my transmission pan this morning and like you I ended up with 3 FULL quarts in the pan!! I poured the old ATF into some empty Mobil1 oil containers and all three were filled to the top ... what's going on? My morning almost turned into a disaster. After changing the oil and filter I tried to remove the trans drain plug. It started to come out easy and then it STOPPED!! I had to make an "exutive decision" ... do I retighten the plug and take the car to my friend's shop to put it on the lift or do I try to remove it and run the risk of stripping the plug and/or the pan and be stuck at home with an empty transmission pan. Well, I removed it and the plug is in terrible shape. It looks like it's been stretched (over torqued) and since the original owner took the car to a Lexus dealership in Plano, TX every 5K miles I have to assume that a Lexus technician is responsible. It just confirmed my resolve to never let anyone work on my vehicles!! I managed to make a new temporary plug by cutting down a bolt in my "assorted metric bolts" box. I'm off to the dealer in a few minutes to pick up a new drain plug and gasket. I only added 1.75 QTS. since you added 2 QTS. and were just about at the high HOT mark. I'm going to check the level cold and then again when it's hot. I'm more concerned about the HOT level than the cold level so I want to adjust the fluid when it's hot.

wwest,

Thanks for your comments. I hope my transmission shifts better now that the fluid isn't so high ... I'll make a post once I've driven to and from work today.

:)

[99lsguy]

k9,

good work on saving the day!

I'm telling you, I believe those guys just throw the ATF in there on a guess! <_<

No attention to detail!

Anyway, my car came from Texas Dealer too! - Maybe they just stop adding fluid when it runs out the top of the fill tube/ dip stick

Torque specs on the bolt is only 15 ft. lbs - I doubt they had it over 40 !

OK, I'm being cruel - but you agree with my point. And I, like you, have little trust when someone else works on my car.

Let us know when the level is perfect!

[JPI]

k9,

good work on saving the day!

I'm telling you, I believe those guys just throw the ATF in there on a guess! <_<

No attention to detail!

Anyway, my car came from Texas Dealer too! - Maybe they just stop adding fluid when it runs out the top of the fill tube/ dip stick

Torque specs on the bolt is only 15 ft. lbs - I doubt they had it over 40 !

OK, I'm being cruel - but you agree with my point. And I, like you, have little trust when someone else works on my car.

Let us know when the level is perfect!

Not every tech throw on the ATF and hope it should be at the stick. How did you ended up with a car from Parkplace?

JPI

[K9crew]

99,

You should be writing maintenance procedures for Lexus! :D You were right on the money with 1.5 QTS bringing the HOT level to the midway mark on the HOT section of the dipstick. I drove about 15 miles and rechecked the level. I added just about 2.0 QTS. in all and now the fluid is at the top of the HOT region. I'm going to drain the pan again this weekend and install my new drain plug and gasket. This time around there should only be 2 QTS in the pan so I'll add 2 QTS of fresh fluid. So I can say with some confidence that I my transmission was over-filled by about 1 QT!! Again, this must have been done by the Lexus dealership in Plano ....

Thanks for your help.

:)

[K9crew]

JPI,

I bought my LS in Houston from an outfit called Expo Motorcars. The car had one previous owner (I think I unerved him when I called him to ask about the rims on the car ... his name was on the title! :) ). I flew to Houston in November and drove the car to San Francisco (via the Grand Canyon and Yosemite). I then shipped the car to Hawaii. I've been in contact with the service people at Park Place. A young woman called Rebecca faxed me the service records from 29K all the way to 58K when I bought the car. I've been trying to get the rest of the records without any luck. I don't know what's going on but I've called many times to speak to her. She keeps promising to mail or fax the records but nothing happens. Initially I was impressed with their service but now I'm beginning to wonder!

:)

[VBdenny]

Hmmm you all have me thinking. I noticed mine seemed a little high but it is hard to tell. The indicator stick isn't all that easy to read.

[K9crew]

denny,

I think that's particularly true if the transmission is over-filled. It's quite easy to read the dipstick if the fluid is in the COLD or HOT regions, but if it's above the HOT region it's hard to read the thin wire part of the stick. I had no idea if my transmission was 1 QT or 5 QTS over-filled!! Anyway, I'm going to take a page out of 99's book and drain the pan at EVERY 5k mile oil change. 2 QTS of Toyota Type 4 ATF every 5k is cheap insurance. Thanks for the idea 99!!

:)

[99lsguy]

K9,

When you do the next pan drain follow the same procedure. I think you'll probably get between 2 - 2.5 quarts drained this next time. Then just put about 1/2 quart LESS back in on the fill up. After warm up, you'll get accurate reading. By my calculations, the Low-Hot mark up to the FULL HOT MARK may be only 4 ounces!

Denny,

Good to have you back bro, been wondering if all was OK on the coast.....

(Your Collinite is good stuff)

JPI,

I knew I would stir up some trouble with my statement. I understand there are some consciencious (spelling?) technicians and such - I just believe they are few and far between. I'm telling you - the LS specs/procedures absolutely CONSUME ME!!

The car was bought through a broker in Wichita who procured the LS (originally from Park Place) off lease.

great thread K9 :D

99

[K9crew]

the Low-Hot mark up to the FULL HOT MARK may be only 4 ounces!

99,

this may be the reason that our transmissions were over-filled or it could be that both of our cars came from Park Place Lexus in Plano, TX. :D Every vehicle that I've ever owned (with the exception of my F-350 PSD) came with an oil pan dipstick having a difference of approximately 1 QT between the LOW and HIGH marks. The LOW HOT and FULL HOT range is about an inch long on the ATF dipstick so it's counter-intuitive to think that the difference is only 4 ounces.

As for my LS, it seems to be driving much better now, the shifts feel quicker and firmer ... I don't think it's the placebo effect but after a few more days of driving I'll know for sure.

Thanks for everyone's input on this thread ... it's helped a lot.

:)