89' Accord Transmission Problem

After Driving the car for about 5-10 minutes the transmission slips into neutral and just revs up. A friend said the problem is probably that after the fluid in the transmission gets warmed up all the "trash" just drops to the bottom and is causing the problem. But I want to be sure before I go and pop 117 dollars on a flush that might not even be needed. and spend it on what else might be wrong.
Uh guess it'd help if I said it was Automatic F.W.D.

Any help/ suggestions on this would be very much apreciated!

Also I crawled up under the car to see if I could just drain the fluid and there is not a place to do so that I could see. Then again I'm not very knowledgeable about the mechanics of cars.

Oh forgot to mention I did a search and did'nt find anything like my problem.

A flush is a maintenance service....was never intended to fix a transmission that already has a serious problem.

99 times out of 100, the flush is going to be a waste of money. If the problem is due to worn clutch packs, the extra shear strength of the new fluid will be the last nail in the coffin. Most times when people bring a slipping tranny for a fluid exchange, it self destructs even quicker after the fluid change.

For that reason we started asking if the tranny service was being done for maintanance or were they having a problem. If problems, we'd send them to a tranny shop. Not worth having people trying to claim the service ruined the tranny....

If you have enough trash in the filter screen to totally block flow, you have enough worn internals to warrant a rebuild....there is no amount of normal wear debris or fluid varnishing that would clog a filter.

The ONLY scenario I can think of where you might get out of this without internal work is if the transcooler was blocked or had a pinched line and the tranny fluid was overheating to the point it falls out of gear after warming up.

In 25+ years of working on cars I've never seen a fluid exchange fix a badly malfunctioning tranny...

I can't really afford to have the transmission rebuilt. I got to thinking perhaps the cooler was blocked. is there anyway to check and see if it is? and if so how hard is it to do?

Talked to a honda mechanic today and he had this to say.
Hondas have an internal pump screen and the garbage gets sucked against the screen after the transmission gets going 5-10 mins until the pump can't suck in anymore fluid causing the line pressure to drop and the transmission feels like it's in neutral. I would recommend a transmission fluid exchanger. An exchanger takes the old fluid out and refills it with new fluid while the car is running. It's like a dialysis machine for car transmissions. Also use Honda's brand of ATF as it has additives that help with shifting. It's not much more expensive or anything and it really helps older transmissions.

The pump screen is quite large and like I said there's not enough normal wear debris present in a healthy tranny to block it, so if it did improve it, I'd wonder what was getting shredded in there so badly and expect more trouble before too long.....there is a couple of small screens in passages in the valve body that can get blocked and cause problems, usually missing shifts...I'm not sure if a flush/exchange clears them or not.

You can remove the tranny lines from the radiator and direct LOW PRESSURE compressed air into the cooler core and verify that it's clear. more than 30 psi or so can rupture the core.

Okay I looked at the transmission today and noticed drops of transmission fluid leaking. From what I know from pipes ect. a leak is a bad thing. What's even odder is that my dipstick reads it full. I appreiciate all your help Jeff, I'm going to save the money up and take the car to a transmission shop. I bought the car for 900 bucks, so I guess I get what I paid for?

Check the level very carefully, full operating temp and running in park or neutral.

Being too full can aerate the fluid and cause enough foam to make line pressure drop off.

Also check the fluid level once it starts slipping out of gear. If it reads way higher than when you checked it before, that can be a sign of an internal pressure bleed-off (blown accumulator, etc) or a badly cavitated pump that can't pump fluid once it warms up.

I was thinking, you could also probably just feel the lines going in and out of the radiator transcooler core...just like radiator hoses you should feel them both warming as the tranny warms up if there's flow present. A blocked core or line would cause one side to remain cold. Be careful as they get pretty hot. I'd check from a cold start, see if they seem to be coming up to temp together.

At any rate if you had one side very cool to the touch even after it began falling out of gear, that would be a red flag.

You hadn't mentioned getting stranded, so what do you do once it starts slipping? Turn it off and wait a few minutes or what?

Yea I turn it off wait a few minutes and start again. My dipstick is located dangerously close to the fans and I have to shove my arm up and under the motor basically to even get to it. and I have to untwist it to check my fluid. so checking it while it's running is out of the question. I'll do what you just said about the trans cooler.

Okay I just did that, and when it slipped out of gear I pulled to the side of the road and put my car in park and I did'nt feel the tranny changing into park. I turned the car off and started it again and changed into drive and I felt the tranny shift into drive. but when it was slipping, no matter what gear I put it in I could not feel the change in gears at all. As for the tranny cooler lines I had one hot and semi warm. (after driving) how ever when It was from a cold start they were the same temp. or felt that way atleast.

You have to check it when running....that's the standard way an automatic's level is checked. The static fluid level is meaningless...
If it reads full when not running it's way low. They'll read an inch or so over the full mark if the level is correct and the motor is not running..

It sounds like the transcooler is flowing fine.

You said it was leaking some. Would be funny if after all this it just needed some fluid...

If that's got the flexible plastic fans they just about can't hurt you...but you could pull the fan relay from the fusebox under the hood if you are real wary of it...the radiator fan won't run with it out (be sure you put it back in)

LOL, that would be really funny, and less cost than a rebuild <.<, but where the dipstick is located, is up and under a ton of hoses which are uhhh hot. <.< So even if I check it after it's been run the levels would be the same as checking it cold? or does the car actually need to be on for me to get a correct reading? (complete novice with cars I actually had to look up trans cooler to figure out what you was talking about :D).

Actually you are right, I forgot those with the threaded stick get checked w/engine off. The level is checked with the stick just sitting on the case, not threaded in.

Didn't mean to get your hopes up. so used to checking them running I got ahead of myself.

The trans is supposed to be warm though. Stone cold is the level at the top of the full range, or just somewhere in the cross marks? Topped out cold would make it slightly overfull at full temp. That can cause aeration.

I doubt it would cause what you got though.

Was this always this way since you bought it, or it just started suddenly? I didn't catch if this is a car you just bought, or had it a while...

I've had the car about 2 months and it's been doing it for about a week. I stoped driving it after it did it to me the second time. It read full after I checked it when the car had just been run.