A Bad Automatic Transmission Mount may be causing My Vibration?
01-21-2009, 05:35 PM
#2
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Location: Okanagan, BC
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There is a linkage underneath my 4runner that lost the "boot" around it. Whenever I come to a stop, and even more so when I shift into reverse, I get a horrendous vibrating sound and obvious shaking in my cab. Not sure of what this linkage is called but it seems to be related to the auto tranny. That might be what your experiencing. Looks like a PIIT to fix, but I'll have to look closer when it gets warmer.
01-26-2009, 08:26 AM
#6
Contributing Member
There isn't really a flywheel on an auto, the TC is bolted straight to a drive plate (flex plate), which is bolted to the engine output (crank shaft flange I guess its called)
I guess you might want to remove the inspection plate (see pic below) and look to see if all the bolts to the TC are tight. You have to rotate the crank around to check them as you can only see them one at a time. I would probably rotate the engine by the crank shaft bolt, but only turn it in a righty tighty direction so you don't loosen the bolt by accident. IIRC there are 6 bolts, one has a slightly different color and shoulder size. It is suppost to be inserted first to help center the TC to the engine.
I guess you might want to remove the inspection plate (see pic below) and look to see if all the bolts to the TC are tight. You have to rotate the crank around to check them as you can only see them one at a time. I would probably rotate the engine by the crank shaft bolt, but only turn it in a righty tighty direction so you don't loosen the bolt by accident. IIRC there are 6 bolts, one has a slightly different color and shoulder size. It is suppost to be inserted first to help center the TC to the engine.
01-26-2009, 08:33 AM
#7
Contributing Member
The drive plate will always be turning when the engine is running as will the TC since its bolted to the drive plate. Correct, the drive shaft doesn't turn in park or else you'd be moving in park. Don't want that, hehe.
Last edited by mt_goat; 01-26-2009 at 08:35 AM.
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01-26-2009, 03:24 PM
#11
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01-26-2009, 03:34 PM
#12
Contributing Member
Shouldn't have to remove those, but I probably did because my tranny was coming out away.
01-26-2009, 07:11 PM
#13
Registered User
Would it be safe to say that the engine is just running rough under load? I mean, you said when you're coasting with the engine turned off there is no vibration, right? And, you still feel the vibration with the vehicle stationary and yet revving the motor. Does the vibration occur at all when idling or just under load/acceleration?
Would it be possible for you to get a very inexpensive stethoscope, have your wife or someone rev the motor in park, and listen around for the source of the vibration? Like at the output bearings, motor mounts, harmonic balancer <<<CAREFULLY!!, etc. That's what I would do.
Would it be possible for you to get a very inexpensive stethoscope, have your wife or someone rev the motor in park, and listen around for the source of the vibration? Like at the output bearings, motor mounts, harmonic balancer <<<CAREFULLY!!, etc. That's what I would do.
01-29-2009, 03:09 PM
#17
Contributing Member
I usually just put in on and start touching the tip on things to hear the noises they make. When you touch the source of a noise its pretty obvious, almost painfully loud sometimes. Just make sure you don't hit the fan or something 
01-30-2009, 05:21 PM
#19
Contributing Member
I guess the flex plate being loose or broken or the t.c. bolts being loose would be worse with rpms being higher. So in that repect the rpms would normally be higher with OD off. But I can't see how that would cause the shifter to move a lot. I don't remember ever seeing movement in my auto shifters. It is only connected to the tranny by a linkage rod 
I don't know let me think about that one.
I don't know let me think about that one.
