Transmission Horror Story - Please Read !

[LuckyApril7]

I decided to change my tranny fluid when i got my synthetic oil change at a Jiffy Lube in southern California. I drove off and a week later i got hard shifting. I would let my car sit awhile and when i shifted out of park, it shifted hard. When i would slow to a red light, the tranny would shift hard to a stop. I thought the worse and went doing some price checks to replace my whole transmission. A rebuilt SC tranny runs $1300 in my area.

I was already in the market of buying a new car so i decided to mask off the problem by changing all the lube in my engine and tranny one last time to hopefully make it smooth for any test drives. I went to a different Oil change place and noticed they poured in an additive that the other oil change place didn't do.

With my curiousity, I asked the mechanic and he told me that Lexus uses special tranny fluid than other cars do. He told me putting in the wrong fluid will cause hard shifting and stalling. To my surprise the problem went away. I drove back to the original oil change place and asked them what tranny fluid they used and to my horror, they told me they use regular ATF fluid and even showed me the bottle.

To make a long story short, Lexus uses Dexron/Mercon 3 for tranny and not all fluids are made the same even though they look it.

[lexus082]

Actually, all Lexus SC400's require Toyota Type TIV Fluid (NOT DEXTRON III). According to some transmission manufacturers, such as Valvoline, some Dextron III is compatible with Toyota Type TIV. But I would just stick with the Toyota Type TIV rather than save a few bucks. But you are correct, using the improper fluid will cause abnormal shifting to occur.

[anthonyiez]

yep toyota type 4 is the way to go. valvoline makes a fluid called maxlife that will work, but the toyota fluid isn't all that much more.

[Walt in Asheville]

I had thought of switching to synthetic Tranny fluid myself. Is there any opinion on using Amsoil Tranny Fluid? Here is the link: http://www.amsoil.com/StoreFront/atf.aspx

[BMAN1113]

I used Amsoil ATF in my 93' SC400. I started to notice that when I really got on it, the tranny didnt seem to want to engage. The RPMs would just keep climbing and I would have to let off of the gas. At normal driving conditions it felt fine. After putting around with the Amsoil for a year or so I decided to switch back to the Toyota T-IV. At 147K I'm now facing a tranny replacement. I keep wondering if it was the year of Amsoil. I can't say for sure, but I wish I hadn't done it. I dont see how Amsoil can say they have one fluid that covers all brands, and they didn't answer my questions very well. They just kept saying that it was formulated to work in all cars. They could never explain exactly how. Different trannys require different friction quotients from their fluid. The shop that I want to deal with has quoted me $4500 for a factory swap out. This bites!!!. I do, however, swear by Amsoil 0W30, although you may end up having to chase a few leaks at first (ie. valve covers) Hopefully the leaks are only minor. Had I heard about this common occurance before switching, I may have decided not to do it. I went to Amsoil at 87K and had to replace the valve cover gaskets a couple of months later. Bottom line... I would use Amsoil motor oil ONLY!!... and preferably in a new car.

[Homer 94sc300]

I have 122k on my SC300, the tranny fluid is nasty, but im afraid to change it cause ive heard stories about it messing it up. Could someone PLEASE help me out here, thanks.

[lexus082]

Just do a series of drain and fills. I bought my car with 117,000 miles on it and the condition of the trans fluid was bad. It was as black as dirty oil. Now after many drain and fills I have safely improved the fluid condition. Its starting to look like the new stuff I am putting in. It took many drain and fills to get mine back to what it should look like. This way you don't have to worry about possible damage occuring as a result of a tranny flush service. Now I'm just trying to get it to be as red/pink as possible. Looks a whole lot better than it did. I don't know how it compares in cost to a tranny flush, but it seems to be a much safer method. Also consider servicing the transmission filter. Overall I think I did 10-15 drain and refills. Make sure you put the correct transmission fluid in for your SC300.

[jzz30]

change your trans filter and all problems will dissappear. and if it happens again, change it again becasue some loose clutch material is cloggin the filter causing it to starve. i did this and it was perfect!

[anthonyiez]

I have 122k on my SC300, the tranny fluid is nasty, but im afraid to change it cause ive heard stories about it messing it up. Could someone PLEASE help me out here, thanks.

i have yet to have a problem flushing a high mileage toyota trans. i use the BG flush machine and it does a complete flush of the entire system.

[lexus082]

I believe there is still a risk factor. Its seems that probably most of the time it will not cause any damage, but it has caused problems for others. Some say that if the transmission has been well serviced then a flush won't cause any problems, but then say if the transmission hasn't been serviced according to the transmission service intervals then there is a higher risk of causing damage. This topics been covered in the past. Do some searches if you haven't already, there should be many different opinions on this matter.

[t0ked]

All SC400s need Toyota T-IV fluid. The SC300 until around 97 or so required plain old Dexron-III (ie. Mobil 1 Synth ATF). Make sure you use the correct ATF. I have a 1993 SC300 and I use Mobil 1 synth ATF for regular drain a fills about once a year.