Front end vibrations with acceleration

[LoganTheJeep]

Hey all! Recently lifted my 04 3.5” (rubicon express, springs and monotube shocks) and went from 30s to 33s. Tires have been balanced, alignment done. I ran out of time to instal the new CV driveshaft and SYE kit but that is being done soon. Whenever I push the gas, I get bad front end vibrations. It’s worse in second gear around 30-35mph. As soon as I let off the gas, the vibrations stop. Any suggestions?

 

[CharlesHS]

The 3.5" lift has changed the angle of your front driveshaft which is what is probably causing the vibrations.
You will need to install adjustable upper control arms to correct the driveshaft to pinion angle.
The adjustment will require a magnetic angle indicator to detect the differences between the pinion and driveshaft angles so that you get close to 0* difference, but maintain approximately 6* caster so you do not have a drifting feeling in the steering while driving on the highway.

 

[Jerry Bransford]

Get the SYE and CV driveshaft properly installed and your vibes will go away. I'd make enough time to do it asap, u-joints don't like being made to vibrate from being subjected to excessive angles.

 

[Artsifrtsi]

Also, check the condition of the front driveshaft and joints in it, the new angles can take a going bad joint to a "I'm gonna explode, and take the world with me" joint, fairly quickly.

 

[Shawn at Tom Wood's]

Get the SYE and CV driveshaft properly installed and your vibes will go away. I'd make enough time to do it asap, u-joints don't like being made to vibrate from being subjected to excessive angles.

I agree with Jerry, as usual. I know that you, the OP @LoganTheJeep, said it is coming from the front end but I wonder if it just feels like it is but is really coming from the rear shaft. The symptoms you are describing exactly match the symptoms we describe as angle related vibrations on our website. I'll copy and past an excerpt below.

1. Angle related. These are typically felt at lower speeds, from 0 to about 40 mph. These are also worse on heavy throttle and load, when accelerating or going uphill. Angle related vibrations are often described as a shudder and usually get better or go away when you let off the gas or shift into neutral. Another sure way to know it is angle related is if the vibration started immediately after installing a lift.

You can find the whole page and more information about drive shaft vibrations here https://4xshaft.com/blogs/faq/diagnosing-drive-shaft-vibrations?_pos=1&_sid=d6ec76a03&_ss=r

 

[Jerry Bransford]

I know that you, the OP @LoganTheJeep, said it is coming from the front end but I wonder if it just feels like it is but is really coming from the rear shaft. The symptoms you are describing exactly match the symptoms we describe as angle related vibrations on our website.

X2.

 

[LoganTheJeep]

Hey everyone! Thank you for the help! I installed a cv drive shaft and SYE kit and problem solved!!