motor mounts
#1
JK Newbie
Thread Starter
Join Date: Nov 2007
Location: HOBART INDIANA
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
motor mounts
does anyone know haow many and where the motor mount are on the jk i've got a vibration problem and think its a motor mount thanks pics would be great
#2
JK Junkie
Please describe EXACTLY the vibration you are having- it's not unheard of but not too likely that a motor mount is bent or broken unless you have REALLY flogged your JK HARD....
#3
JK Newbie
Thread Starter
Join Date: Nov 2007
Location: HOBART INDIANA
Posts: 60
Likes: 0
Received 0 Likes
on
0 Posts
mounts
jeep vibrates in neutral and in drive i had a fender bender that only messed up the plastic bumper cover it hit the crush can on the driver side jeep dealer said they could find why it was vibrating its driving me nuts
#7
JK Junkie
Yeah a hit on the end of the frame rail will cause enough engine shift to bend/shift a motor or tranny mount. You have a mount tab bent and barely touching under acceleration. A motor mount is made up of 2 brackets, one is bolted to the side of the block, the other is bolted to the engine crossmember or frame rails. These 2 brakets are bonded together with a thick rubber pad which is strong enough to hold the brackets together, yet flexible enough to absorb engine torque. Since the Motor Vehicle Safety Act of 1968 all engine mounts are required to have entertwined tabs which lock the mount together in case the rubber breaks or an accident damages the mounts. Normally these tabs don't make contact, but after being bent they sometimes will rub under acceleration. In the pre-tab days when a motor mount broke and came apart the vehicle would go to full throttle when the engine shifted position without a complete mount to hold it in position. Nowadays you just get a vibration. Look under the hood and see which direction the engine twists when taking off. On the down-side motor mount check the bottom of the mount assembly with a flashlight very carefully, many times the rubbing tab will be shiny where it is touching under acceleration. On the up-side mount, check the top of the mount for the same spot. If all else fails, replace the down- side mount first. If that cures your vibration, you won't have to buy the second mount. Best of luck!!!
Trending Topics
#9
JK Enthusiast
Join Date: Jan 2009
Location: Charlotte, NC
Posts: 414
Likes: 0
Received 0 Likes
on
0 Posts
I did the exact same thing to mine a few weeks ago when I was offroading. It vibrates like a mofo in N and D, but not in park. I hit on the exact same spot as yours when I went in to a dirt ditch. I was thinking its the motor mounts too. Let me know if yours is fixed if you replace anything...
#10
JK Junkie
motor mount pics
Hi- got your PM, it's dark now but I was able to get a couple of pictures, hope it will help you a little bit. The first picture 003 is of the right motor mount from directly underneath. The long ''c'' shaped bracket with the 2 holes towards the center is what should concern you. See where my finger is pointing to the 1/2'' gap between the ''c'' frame bracket and the black cast mount? if this end of the ''c'' bracket is bent the gap will be gone and the mount and bracket will rub, causing vibration. The ends of this bracket should be 90 degrees compared to the 8'' bolt running thru the whole mount assy. The second picture is of the left side mount assy, looking from directly underneath. This left mount is probably your culprit, since the impact point was your left frame rail. Make sure that 1/2'' gap is there. If the ''c'' tabs are bent you can jack the motor up slightly with a piece of 2X4 under the oil pan to take the weight off the long (8'') motor mount bolt. Remove the bolt only from one side at a time, and hammer the ''c'' bracket tabs back to a 90 degree configuration. Reinstall the long bolt and check for vibration. This entire line of advice is based on the premis that your accident could have caused the motor to shift, bending the motor mount brackets. I fix wrecks for a living, so I have seen this result many many times. Remember it could be something else, I'm not on the scene. Give this a try, it might cure what ails ya.... Remember the driver's side is always LEFT, the passenger side is always RIGHT...
Last edited by TINMAN080; 04-09-2009 at 04:57 PM.