2009 2 Door JK (Sluggish and Vibrations)
Thread Starter
JK Newbie
Joined: Jun 2012
Posts: 3
Likes: 0
From: West Chester, PA
2009 2 Door JK (Sluggish and Vibrations)
Ok, please bare with me as I am new here as well as to the lifted Jeep concept. I have a 2009 2 Door JK that I recently had a 3.5" AEV Lift and Mickey Thompson MTZ's (325/65R18) installed on.
Let me tell you what was done and how it is responding.
I had the 3.5" AEV lift installed with the stock wheels and tires and it road well. The next day I took it to the tire shop and had the MT MTZ (325/65R18's) installed. They remounted, balanced and aligned the tires. I took it home and it seem to run well. I drove it about 300 miles (All highway) and heard a rattle. I took it to the local jeep dealer and they told me the driveshaft was rubbing because of the increased pinion angle. I took a look with the service tech and absolutely it was. I had one shipped directly to the dealer and they installed a new Tom Woods DS the next day. I took the jeep home and recalibrated with the Pro Cal. (For the larger tires) Doing the measurements I am showing 34.25 inches. Now the jeep seems to be vibrating during acceleration? Someone told me that I would have to change my pinion angle to correct that? I do have ******* upper adjustable control arms...? Will that take care of the low speed vibrations? The next issue seems to be that the jeep "Holds" in gear before shifting. Almost sluggish. It is an automatic. I want to prevent tearing the transmissions up etc. How would I correct that? Also, do you recommend making any other modifications to increase gas mileage and not tear the motor/tranny up. Thank you all for your help in advance!
Let me tell you what was done and how it is responding.
I had the 3.5" AEV lift installed with the stock wheels and tires and it road well. The next day I took it to the tire shop and had the MT MTZ (325/65R18's) installed. They remounted, balanced and aligned the tires. I took it home and it seem to run well. I drove it about 300 miles (All highway) and heard a rattle. I took it to the local jeep dealer and they told me the driveshaft was rubbing because of the increased pinion angle. I took a look with the service tech and absolutely it was. I had one shipped directly to the dealer and they installed a new Tom Woods DS the next day. I took the jeep home and recalibrated with the Pro Cal. (For the larger tires) Doing the measurements I am showing 34.25 inches. Now the jeep seems to be vibrating during acceleration? Someone told me that I would have to change my pinion angle to correct that? I do have ******* upper adjustable control arms...? Will that take care of the low speed vibrations? The next issue seems to be that the jeep "Holds" in gear before shifting. Almost sluggish. It is an automatic. I want to prevent tearing the transmissions up etc. How would I correct that? Also, do you recommend making any other modifications to increase gas mileage and not tear the motor/tranny up. Thank you all for your help in advance!
JK Enthusiast
Joined: Aug 2010
Posts: 345
Likes: 0
From: Orlando, Fl
New Gears?
Out of curiosity, what is the gearing in your Jeep? I have 33" Duratracs on my 08 JK automatic. I was thinking about going to 35" tires, but I kept seeing people mention that the auto tranny with 35" tires usually needs a re-gearing and I'm not ready for that upgrade yet. Might be something to look into. Good luck!
JK Newbie
Joined: Apr 2012
Posts: 53
Likes: 0
From: Sherman, Texas
I have a 12' unlimited with a 4" lift and 35's and I haven't had any driveshaft problems or rattles but as far as regearing for the auto trans, you will notice most at hwy speeds if you try to use the cruise control. I need to do it myself. Defiantly next on the list of things to do....