How can you tell if your tranny is slipping?

[Soilent Green]

'98 Camry, 263 000kms, auto 4cyl.

I feel a slight shudder sometimes when the tranny shifts, my acceleration is kind of slow and the 1-2 shift isn't smooth at all unless I deliberately make it shift at like 3000 rpms, wich seems high.

Can somebody who experienced tranny slipping describe how it feels, like does it makes a sound or is there tremendous vibration or shudder?

I read at a couple places that when the tranny slips your RPMs rev up but of course, the car doesn't move. I have a hard time believing you don't hear some kind of screech or feel any vibration. It can't just rev up like you didn't put it in gear...something has to be grinding somewhere in there....

[Brian R.]

When your tranny slips because of worn clutches, there is no noise. Your engine revs without accelerating the car. Same thing as if you had a manual transmission and your clutch wore out. It wouldn't grab, just slip without transmitting torque to the transmission.

In answer to your question, you can tell your clutches are slipping when you push on the accelerator and nothing happens except increased engine noise.

[idmetro]

As stated above when the transmission is slipping you will notice the engine rpm increase and the speed of the car decrease.
I'd start by changing your trans fluid and filter. I changed the filter in my 91 and switched from basic atf to mobil 1; it made a noticable difference in the smoothness of the shifts. After having had to replace a transmission due to neglect (read lack of regular maintenance) I say good fluid is cheap insurance. I've read some posts where people really like redline D4 ATF even better but haven't tried it myself.

[Soilent Green]

I don't think it's slipping but I get some shudder when shifting sometimes and my acceleration is slow. I know, I'm driving a camry but still it feels like I would be beaten by a wheelchair on a red light.

[kable336]

All The Above Is True But You Should Try A Automatic Transmission Cooler.