Strange Motor Vibration when at 40-45 mph

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Jul 1, 2014 | 09:44 AM
  #1  
So I have a 95 jeep Cherokee country that runs and drives just fine except when I get to 40 or 45 mph then I get this strange vibrations feels like it's coming from the motor. I see that the rpms drops when I get to 40-45 mph, if I step on the gas its gone once I hit 50mph.


Anyone has any ideas what this might be let me know. I'm open to any ideas.
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Jul 1, 2014 | 09:47 AM
  #2  
Is it lifted? What motor does it have? Where do you feel the vibration, in the pedals, seat, or steering wheel?
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Jul 1, 2014 | 10:24 AM
  #3  
It's is stock for the most part I have some 235/75/r15s on it. It has the 4.0 straight 6. And for the most it feels like its coming from the engine, you cant really feel it in the petals or in the wheel.
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Jul 1, 2014 | 10:42 AM
  #4  
Auto trans? May not be the engine. 40 to 45mph is the speed at which your trans and torque converter goes in and out certain modes.
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Jul 1, 2014 | 10:52 AM
  #5  
It is an auto. How would I go about checking something like this, I have never heard of it.
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Jul 1, 2014 | 11:12 AM
  #6  
First thing I'd try is adjusting the TV (throttle valve) cable. I can't find the procedure (had a computer crash). Someone will reply I'm sure. How does it seem to shift?
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Jul 1, 2014 | 11:25 AM
  #7  
there are times when it seem to shift slow, or is going way over RPM's to shift. When it hits 40 to 45 RPM's seem to drop down to 1500, then when you go heavy on the throttle it will recover and then shift into 5th.
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Jul 1, 2014 | 11:30 AM
  #8  
Yeah start with the TV cable adjustment. Its literally a 2 minute job and requires no tools.

Like said above, its right before where the metal cable comes out of the plastic at the throttle body. Mine is a 95 and I have the white plastic clip. If its the white clip, take a small pic or pocket screwdriver and gently pry the clip straight up. It may come off but it only needs to come up a little. If its the recessed square button (most are black) then use a screwdriver or something to push the button in and move the cable forward or back.

BTW it is not a "kickdown" or "detent". Most people dont care about terminology but its the Throttle Valve cable "TV". This is a pretty critical adjustment, if its too loose it will upshift very quickly, also causing low trans pressure and possibly burning the clutches/bands. If its too tight then it will shift late and harsh. A little movement can change quite a bit, so you might need to move it a few times.

If anything you might prefer a little on the tight side <haha.. If its a little tight, it will shift a little firmer, hold gears a little longer and downshift a little more sensitve. I usually set mine like that, it works a lot better when crawling around off road and it doesnt make upshifts/downshifts so busy.

If you want to tighten the cable, release clip and pull plastic cable housing away from throttle body (pass side), to loosen cable then pull cable housing toward throttle body (drivers side) You should see the affect it has on the cable.

-compliments of jnicewan from another post
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Jul 1, 2014 | 11:32 AM
  #9  
Quote: there are times when it seem to shift slow, or is going way over RPM's to shift. When it hits 40 to 45 RPM's seem to drop down to 1500, then when you go heavy on the throttle it will recover and then shift into 5th.
X2 on adjusting that cable then.
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Jul 1, 2014 | 11:49 AM
  #10  
I will give it a shot, Thank you for the help!!!!
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Jul 1, 2014 | 12:01 PM
  #11  
Keep in touch.
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Jul 2, 2014 | 09:49 AM
  #12  
Update,


I was able to adjust the TV cable last night, and for the most part the vibration is gone, It dose it for just a second at 45 mph but, its no longer dropping rpms at random times and seems to be shifting correctly now.


Thank you a ton for all the help.
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Jul 2, 2014 | 09:53 AM
  #13  
I may have spoke to soon, my wife says that it is still doing it. But now I have somewhere to start. If you have any other ideas on what it might be let me know.
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Jul 2, 2014 | 10:08 AM
  #14  
With the OD off does it still do it at that speed?

Max
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Jul 3, 2014 | 11:04 AM
  #15  
I don't have over drive, or at least that I am not aware of.
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