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Posted

I have a 1995 Lexus ES300, my problem is that when I first start the car it works ok for the first 2 min. then every songle gear slips, no grab whatsoever, I hooked up an OBD to it and its telling its low pressure, what can be causing this, I have benn told it could be my ECU, ant ideas would help


Posted

pull you tranny dipstick when the motor is at normal operating temp and the car is in P or N. (put your e-brake on!!!)

Is the level correct (should be at HOT mark) and what color is the fluid on the stick?

steviej

Posted
I have a 1995 Lexus ES300, my problem is that when I first start the car it works ok for the first 2 min. then every songle gear slips, no grab whatsoever, I hooked up an OBD to it and its telling its low pressure, what can be causing this, I have benn told it could be my ECU, ant ideas would help

Insuffient data to compute....How does it drive from a stop, hot, in Low then manualy shifted to D2....OK, or still slips? How does it drive with the ECU out of the loop? disconect your A/T solenoid harness. Watch the tach...is it slugish or slipping with no ECU input? ECU problem is unlikely in that year. Why do you say the scanner reads low presure since A541e's do not give presure readings via the scanner like GM's hydromatics do. Did you connect a mechanical presure gauge?Do you have a code? would you like to share it with us? Sounds like a mekacked forward clutch pack but I need more info bro.....Anyway, what does it mater, you need an experienced A541e A/T guy. Not something you can do at home.

Posted
I have a 1995 Lexus ES300, my problem is that when I first start the car it works ok for the first 2 min. then every songle gear slips, no grab whatsoever, I hooked up an OBD to it and its telling its low pressure, what can be causing this, I have benn told it could be my ECU, ant ideas would help

Insuffient data to compute....How does it drive from a stop, hot, in Low then manualy shifted to D2....OK, or still slips? How does it drive with the ECU out of the loop? disconect your A/T solenoid harness. Watch the tach...is it slugish or slipping with no ECU input? ECU problem is unlikely in that year. Why do you say the scanner reads low presure since A541e's do not give presure readings via the scanner like GM's hydromatics do. Did you connect a mechanical presure gauge?Do you have a code? would you like to share it with us? Sounds like a mekacked forward clutch pack but I need more info bro.....Anyway, what does it mater, you need an experienced A541e A/T guy. Not something you can do at home.

The fluid level is ok, not burned or anything like that, If I start the car it will go for the first 2 min. after that no gear works, not low, 1,2, reverse, none of them. I didnt know there was a solenoid harness. I have not tried it. I actually took it to the dealer I bought it from, I towed it over there, his mechanic was the one that told me it was low pressure, the rpms, will just rev up, the engine works fine, but after those first 2 min. i have no traction what so ever, the car will not move an inch. I know I can't fix it but I want to have an idea before I take it in, because any place will pill the trannie, then tell me whats wrong with it, then they will charge me weather I fix it or not, I just want as better understanding before I get ripped off.

Posted

If you shut the caroff and restart will it move for 2 minutes again and stop.

Sounds like a plug in the filter or valve body clogging the pressure transfer.

I say this alot latly but try adding an external filter and letting it idle for a while

Posted

I refer this one to my Chineese assistant :Som Ting Wong

Reverse is pure hydro-mechanical. If you loose reverse, it rules out the ECU, A/T solenoids and wiring....basically the cheap stuff. I do not have TIS or a manual in front of me....I will double check monday, but there is a machanical clutch called a sprag that allows the output shaft to rotate in one direction and lock in other...F2 sprag failure will give you a slipping/neutral condition but I think you still get reverse.... again I'll double check Monday. Presure loss if he realy checked it can be caused by restricted filters, worn pump, binding presure regulator valve...may be binding on debis or scratches in the valve bore. Hot oil has lower viscosity than cold, so it sounds like you are on the threshold of slipping. What happens if you take the car cold, idle in park for 10 minutes? will it move for the full 2 minutes then? Reverse takes much more pressure than forward gears due to gear reduction issues. You can try SKPerformances filter, it won't hurt and might help. Our filters are mesh screens like your front door screen.... Stops flies but not dirt. I think it's replacement time for you unfortunately.

Regards, Som

Posted

I was wrong about the sprag and I thought I might have been. If you have good presure in P and N and then experience presure loss in D and R it is in the forward clutch circuit like I first posted....if you have low presure allways presure reg in valve body, filter, pump etc. No simple fixes here. The box needs to come out and appart. I suspect it is low psi in D and R only and you have either blown out a C0 (forward clutch) accumulator seal or pipe, or had the C0 piston seal fail. Is the tranny pan dented near the front?

Posted
I was wrong about the sprag and I thought I might have been.  If you have good presure in P and N and then experience presure loss in D and R it is in the forward clutch circuit like I first posted....if you have low presure allways presure reg in valve body, filter, pump etc.  No simple fixes here.  The box needs to come out and appart.  I suspect it is low psi in D and R only and you have either blown out a C0 (forward clutch) accumulator seal or pipe, or had the C0 piston seal fail.  Is the tranny pan dented near the front?

The pan is not damaged, The car wil not work in any gear, If I start the car again it does the same thing. Another thing I noticed about a month before my trannie when out, was my abs light would come on while im driving and then shut off it would only last about 5 min. also the gauges would turn of and on, and the A/C would also turn off and on. any connection? I dont have a code, I actually just purchased an OBD reader, it should be here this week, I will let you know exactly what I find.

Posted

Since the transmission works normally when it is cold, the underlying problem sounds like it is electrical / electronic rather than mechanical in nature. This is good news if you can track down the gremlin.

The Japanese company Aisin has built tens of millions of highly durable automatic transmissions over the past 40 years. All these transmissions have been equipped with metal mesh filter screens. Obviously if the metal mesh filter screen did not do an adequate job of filtering the transmission fluid, Aisin engineers would have changed the filter design decades ago. But Aisin continues to use their time proven

metal mesh filter screen design so auxillary filters are not necessary and using them might be risky.

Posted

vgr to the point of it works so it can;t be improved.

some how ford is still in buisness selling garbage cars.

I guess that is why i can drive again after very knowlegable techs told me i HAD to get a new tranny.

Posted
Since the transmission works normally when it is cold, the underlying problem sounds like it is electrical / electronic rather than mechanical in nature.  This is good news if you can track down the gremlin.

The Japanese company Aisin has built tens of millions of highly durable automatic transmissions over the past 40 years.  All these transmissions have been equipped with metal mesh filter screens.  Obviously if the metal mesh filter screen did not do an adequate job of filtering the transmission fluid, Aisin engineers would have changed the filter design decades ago.  But Aisin continues to use their time proven

metal mesh filter screen design so auxillary filters are not necessary and using them might be risky.

One of my questions was if the A/T worked in reverse....he said no. There is no solenoid activated for reverse....as I stated, R is strictly hydro-mechanical in nature. Therefore diagnosis proceds as determining what component is activated in all gears 1-2-3-OD and reverse. CO (forward clutch) is active in every gear but o/d. If the car won't go 40mph you cant get to OD. Simply removing soleniod wires will activate a trany in limp in mode...2nd gear starts (sluggish but no slip) and a crisp up shift to 4th when 3rd would normaly come in. This is a valid check for forward, direct and O/D clutch packs. BTW, Last friday I replaced a tranny with less than 12,000 miles on it with a direct clutch pack that was so overheated from slipping the multidisc pack was fused together. They are good, not perfect. I bet you would be hard pressed to find a 97-98 Rav 4 with an OEM tranny in it. Diferential spyder gear washers exploding, and because of filter design it got pumped everywhere and we lost forward and direct pacs.

  • 1 year later...
Posted

:chairshot: Ok, My mechanic told me exactly what I did not want to hear. My transmission was doing the same thing, I always warm up my car before I drive it; but, it was making a squealing noise that I was concerned about, then it stopped. It worked fine for a few miles, then stuttered a bit, RPM's dropped to idle speed, the engine would rev when I stepped on the gas, but no speed was gained. So, I pulled over. When I tried to shift gears (to all of them including reverse) as I sat there, nothing. So, I parked it and called a tow truck. No codes when I took it in, no warning lights pre, during or post that incident. I am buying a transmission as we speak! :cries:

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