I have a 2000 GS300 with 180K and an automatic transmission.

About 4,000 miles ago, I took the GS into my mechanic for a transmission flush. Last week my wife was saying how the tranny seemed to be shifting funny. I took it for a drive and noticed that the tranny was lagging/searching when trying to shift from 1-2 and 2-3. I checked the tranny fluid level and it was about two inches above the high hot mark on the dip stick. I took it to back to my mechanic on Saturday, he checked it and agree that it was high. He said it was about a pint high. Not sure if he’s accurate in saying that two inches above the hot high mark is a pint or if he’s trying to minimize the problem. But he said I should take it to a transmission shop on his tab, and they could determine if the correct atf was added and if any damage had occurred as a result of the high atf level. But the tranny shop is a place that the mechanic recommends business to so I’m worried that bias, in the mechanic's favor, would influence the tranny shop’s findings.

So I wanted to get CL’s take on the damage. How much damage, if any, has driving for 4,000 miles with excess tranny fluid caused the tranny? If damage has occurred, what type of remedy should I request from my mechanic?

Thanks.

 

An article i found on the web...

"Too much fluid can cause the fluid to foam, which in turn can lead to erratic shifting, oil starvation and transmission damage. Too much fluid may also force ATF to leak past the transmission seals."

 

Yup. Too much fluid will increase the pressure inside the tranny, and eventually your seals may not hold up.

I would drain the tranny fluid and pour in new fluid until it's at the correct level. Or you can get them to use a siphon pump and pump out the fluid through the dipstick. That's what I did when I poured a bit too much in.

 

Great thanks for the info. I examined the tranny more closely and there does appear to be a leak which I've never noticed before. So maybe the extra pressure is causing the gasket to leak.

The tranny shop will be doing a complete flush and analysis of the damage tomorrow, but I'd like to get a second opinion as to the extent of the damage.

Do you think driving with an extra pint of ATF for 4,000 would damage the tranny? Should I be worried about damage and thus make a stink about this with the mechanic or is driving 4,000 miles with the excess ATF insignificant?

 

I have always had my RX300 ATF's level above normal and not a single issue, it goes well past the Hot mark and to the IV in Type IV.

 

So, the guy at the tranny shop got back to me and I wanted to see if his answers are accurate or if he is watching out for the mechanic that added the incorrect amount of tranny fluid.

He examined the fluid level and verified that the ATF level was a pint high and said that this was not causing any of the shifting problems.

He also said that the small tranny leak was not a result of the pressure caused by the high ATF level because if there was excess pressure then the excess ATF would come out of the dip stick tube.

He also took the car for a ride. He said that the tranny was flaring (slow shift) between 1-2 and 2-3. He thought the flaring was due to the tranny flush performed 4,000 miles ago because the new ATF has detergent in it that cleans the metal build up in the tranny causing gaps in the gears or clutch that causes the flaring.

He also said that he would recommend us to stop driving the car because the problem would get worse very quickly and cause more damage.

Finally he said that there was no additive or supplement I could add to the tranny to make the tranny shift smoother.

Do these claims seem accurate?

 

I've also heard that a full flush can be bad for higher mileage transmissions.

here's what I'd try first...

drain the trans and refill it with 2 quarts of toyota type IV.
reset the ecu.

see what happens.

 

Tranny has a blow out valve, that ejects extra tranny fluid, dumb as mech overfilled mine and my tranny started to dump the extra fluid, scared the ***** outta me, after I started noticing fluid all over my rear bumper and my exaust. went back at told his foolish *** to remove the extra fluid after that care ran fine.. you gotta love the Japs! they thought of everything.

 

Thanks Chuck. I'll give the drain and fill a try.

I'm also considering adding some Lucas Transmission Fix. After searching CL, it seems that no one has gone wrong using it.

 

I dont know about the rest of the guys, but i would NEVER use any adictive in the transmission. The transmission is the most complex mechanical machine in our cars. It's rather sensitive to problems and harder to diagnose/fix when problems start to come up.

A drain and refill alone is good enough.

 

Honestly, even if the overfill caused an issue, at 180k it wouldnt be a bad idea to have a rebuild. Not saying that overfilling didnt contribute to the issue but now that you know that overfilling occured you are probably also being extra sensitive to any transmission abnormality. Kind of like the , "I added an exhaust and my car is louder so it feels faster" thing you know? I'm not saying the overfilling didnt do anything but you are going to have an EXTREMELY hard time getting anyone to service abnormal shifting in your 180000 mile tranny under warranty from a tranny flush. Honestly, I would just bite the bullet and get a rebuild and drive the car another 180k

 

lucas additives are wonder workers, they are the only additive i would ever put in any of my cars. lucas products are race proven and the only reason some cars are still on the road. sorry had to hype a great product

 

damn!!i got the tranny flush a year ago and put around 12k miles on my 99 gs300 and yesterday my tranny started down shifting and acting crazy on me!!when i checked the oil stick it was way over the h point.i took out oil till it reached the proper level.the tranny is still acting crazy!!! damn i should have checked the oil level.please help!!!

 

I'm telling you man...when I got a tranny flush and fill about a year ago I thought my tranny was shifting funny too. I found out that the level was too high by about 4-5 ounces! I drained a little bit and it's a full 180...perfect shifting; not an issue since (knocking on wood).

 

OP.. Which machine did your tech utilize to exchange your transmission fluid? The transmission should never be "flushed" per-se, rather, a fluid exchange service should be done on the tranny. My guy uses the T-tech machine, and I have never encountered problems or overfills of the transmission..