I have a '99 4Runner with 4WD and 130k miles. I have noticed recently when I start out and I take my foot off of the brake slowly, the car starts to shake. Also when I accelerate very slowly, it does this slightly. It is smooth after I start accelerating or if I take my foot of the brake switftly. Does anyone else have this issue? Is it a brake issue? Any help will be appreciated, thanks

Brian

When you say it starts to shake...what starts to shake? Is it the steering wheel you're feeling it through? The brake or acceleration pedal or is it the vehicle in general? What's your best guess of the source?

I would say its the whole car shaking/bucking. The steering wheel does not shake. I would say its the brakes. But could it be the tranny?

Ok, the problem has progressed. I am pretty sure it's the transmission. When I stop at a light or stop sign, the car will slip out of gear. It will be in drive, then when I step on the gas, it just reves like it's in neutral. I have to put it in park, then back to drive several times to get it going again. I did check the tranny fluid and it is low. I will add some in the morning. Any other suggestions?

if the fluid has not been changed for a while or if it is not reddish anymore or has a burnt smell, you may want to drain and replace...better be safe than sorry.

Yup, check fluid first. Otherwise, could be shift solenoid (any CEL?), or first gear shift sprag. If it's the latter, start looking for a used low-mileage tranny to replace yours. That's what I ended up doing.

good idea^

aside from draining the ATF pan, before replacing fluid, you may want to drop the pan, clean the filter and soleniods... this one i have done with assistance from my mechanic friend... my tranny was whirring also before.

no whirring now.

Have you lubed the driveshaft lately? When you come to a stop it can bind up, and when you let off the brakes that binding can be felt as it releases. Lube it up and see if you still have an issue. I had the same symptoms, and that fixed me right up. It took a few times before things would stay lubed up as I guess the seals were dry, you have to keep at it.

Ok, another update. I had the same problem this morning going in to work, I would stop at a light/stop sign, and it would just magically slip out of gear into neutral and just rev when I wanted to start again. I took it to the dealer to check it out. Of course in front of them, I could not replicate the problem. The shaking still happens when I lightly take my foot off the brake, but the slipping out of gear does not. I asked the mechanic if he did anything and he said he cleared two error codes, non related, one was for an overheat, and one was for a non standard key being used int he ignition. He said that may have happened before and it was saved in the computer. Could that have solved my problem of the tranny slipping out of gear?

Well just an FYI. When the mechanic dropped the pan, he noticed fluid in the transmission (radiator fluid). A few months back, I had the pink milkshake scenario happen to me. Replaced the unit, flushed the fluid 2 different times and thought I had all of the fluid out, guess I did not. So I flushed it again, and now all of my symtoms have gone away. I have my fingers crossed and hope the tranny wasn't damaged too much.

Oh, look for a new trans now. The milkshake gotcha!!!