I had 11 quarts of my ATF drained and filled last month. It seemed like most if not all of the fluid was fresh and red. But this morning I had 2 quarts drained and filled with my oil change as usual, but the ATF came out very dark. My mechanic told me the transmission is going bad and it's just burning out all the new fluid. Any advice? I don't want to rebuild or replace at this point.

 

Please give us more detail about your car, year, model, mileage and driving condition???
How you drain and fill 11 qts? Did you use the power flush( hooked up to the machine)?.

 

1998 GS400 with 150k-ish miles. Mostly highway?

I did the drain and refill for him through the transmission return line. It took 11 quarts before the fluid coming out of the line turned red again. His mechanic said the clutch pack might be failing, which I was leaning towards in the first place. Then again, it could be something else. I wouldn't be able to tell unless the tranny is apart

 

Any aftermarket mods, like supercharger, and driving condition? It's very rare that the trans on the GS400 goes bad that quick unless the driver has some mods or racing. I've seen some GS400 with over 200k without any problem with the trans.
May be this is one of a few.

 

His car is has been stock except for the K&N intake, but the fluid was dark prior to that. I dont think the previous owner has ever heard of a transmission fluid drain and refill before. No racing, just normal cruising.

 

I wouldn't worry about the color of the fluid really... sure, the trans may be on its way out, or maybe its not... has the trans filter been changed?

my car has almost 200k on it, and the fluid in it is drained and filled regularly, but not all the time, nor have I ever flushed it... it still works great...

so long as its working, and you maintain the fluids, keep driving...

 

Thanks Henry, you know pretty much everything about my car.

I guess I'm gonna take your advice with the tranny cooler and the lubegard. Guess it can't hurt.

 

I was at autobacs today and it looks like they do carry Lubegard. I guess it's catching on now. It use to be that only one or two stores around here selling it. My fluid doesn't get oxidized nearly as much ever since using Lubegard.

 

My car has 174k on it, and i drive it hard regularly, and it shifts great still!

As far as installing a trans cooler, i think its fairly pointless. If you arent racing the car, or heating up the trans fluid unnecessarily, then a cooler wont help you much, as the factory cooler built into the radiator works great for stock applications.

 

Does the car still shift ok? My GS300 had dark trans fluid a few years ago. I started having Dynamic drain and fill it when I would do oil changes (every 4K miles). The fluid looks ok now at these intervals, but after quite a few drain and fills. I would suggest draining and filling at shorter intervals, but don't let someone sell you a transmission rebuild if it still works / shifts fine.

 

It definately shifted smoother after 11 fresh quarts but from park to reverse it's not smooth as it should be.

What's driving hard BTW? I'd say I floor it maybe once a day. I figure the tranny cooler can't hurt?

 

motor/trans mounts.... what it sounds like you are getting is the trans twisting from a naturally forwards motion to a rearwards motion and causing a jolt... loose / worn mounts can cause this... also driveshaft bushings will cause something similar...

 

is there anyway to check if it's the motor mounts? cuz the driveshaft, well have to get under the car and everything. mines does the same. when i shift it into like reverse or park, it jolts into that direction. thought it was just normal, guess not.

Peace out

 

a little is normal... alot is not... it's hard to say what is bad enough to warrant replacement... and many times its simply something to live with...

motor mounts... put car in drive, one foot on brake, one foot on gas, have someone watch the motor to see how much it moves side to side - also, get a flashlight and watch the mounts (one on either side, just south of the upper shock mounts) then do the same, but in reverse...

 

hmmm alright. thanks man. will do that when either my brother or dad gets home.

Peace out