Jeep shakes violently

[ParsonMac]

I took the Jeep I'd just purchased to Moab on it's debut run and it performed great, no problems. Took it for a spin the other day and ran over some railroad tracks and while coming off them the Jeep started a violent shaking with the shifter moving from side to side. Reproduced it on the return trip and clutched and braked to see if that would stop it - no go. Seems now (or did I not notice it before?) the shifter is closer to the rear of the hole and hits the tub in 2nd and reverse. I noticed this shaking will not occur at speeds of 20 mph or less. Checked the engine mounts - practically new and tight. Transmission mount? Ordered both the main mount and the stabilizer rod and bushings. Front end seems tight - nothing loose etc. Help!

 

[sjlane]

Check the lug nuts. One or more may be cracked, broken or loose.

 

[SteelHeadz]

Check this out. http://www.jeepz.com/forum/suspension/29510-wrangler-death-wobble-what-causes-how-fix.html

 

[Gennybro]

Check the engine mounts again, not just the rubber that you can see,but directly under them where they are connected to the frame.Have a helper get in the jeep and put it into gear and see if the engine moves up and down or tilts in any way. The small piece of frame work under the engine mount is really flimsy in my opinion. It is connected to the bottom of the engine mount and then connected to the frame itself.Its about 2" in hieght by 6" long.

 

[sweetpeet]

I took the Jeep I'd just purchased to Moab on it's debut run and it performed great, no problems. Took it for a spin the other day and ran over some railroad tracks and while coming off them the Jeep started a violent shaking with the shifter moving from side to side. Reproduced it on the return trip and clutched and braked to see if that would stop it - no go. Seems now (or did I not notice it before?) the shifter is closer to the rear of the hole and hits the tub in 2nd and reverse. I noticed this shaking will not occur at speeds of 20 mph or less. Checked the engine mounts - practically new and tight. Transmission mount? Ordered both the main mount and the stabilizer rod and bushings. Front end seems tight - nothing loose etc. Help!

despite what everyone else says, it really sounds like its you u-joints more that anything. the issue with the speed just shouts u-joint. check your u-joints whether they are relatively new or not they could have gotten messed up somehow.

 

[ParsonMac]

Thanx all for your input. You've been very helpful!

 

[Jmarch68]

Tighten the track bar and check the bushings. If it seems tight, tighten it some more. Don't forget the frame end.