sheffeaj

Hey guys and gals,

I have a 99 Cherokee that I (and 2 other guys) just installed a 4.5" Zone lift in and put 33's on her. While driving it I get a decent amount of vibrating/rumbling (not death wobble) when I accelerate that goes away after about 45-50mph or when I get to my cruising speed. If I stay under 45-50mph it simmers down a bit but is still there. Additionally I have a weird grinding sound that comes from the back when I let off the gas that lasts for only a second or two but wasn't there before the lift. It is my daily driver that I like to get real dirty on the weekends.

I know right after putting a lift in the alignment is going to be off by miles and that could be causing the vibrating (more like rumbling). So as expected when I took it to a shop to get the alignment and tires balanced, the guy told me I need a new extended (or drop) pitman arm as well as the TC drop blocks in order to get a proper alignment and everything needed to be re-centered including the whole axel, draglink/ trackbar and so on, also the whole steering system was way out of wack. The guys that helped me put the lift in said the TC drop wasn't absolutely necessary right away so I was just going to do it later. However I'm more concerned about the pitman arm...is it something that I need?

Also, I was looking at different feeds about an SYE, they said that this could be part of the vibrating/ rumbling problem...and at some point I want to put one in but not yet (due to lack of funds). Is it something that I can live without for a bit or do I need to put one in right away and bite the bullet by dipping into my savings?

Now that I asked all about the front of my jeep and those issues what about that grinding (that sounds like its in the back) when I let off the gas, what could that be? Its more of a medium pitched noise (not too high like a whine or grinding on a bench grinder and not low like a snow plow on asphalt) Here I'm completely lost and have no idea what it could be seeing as its only when I take my foot off the gas and only lasts 1-2 seconds...

I'm banking on the alignment and the tires getting balanced as well as everything getting re-centered to fix the issues with the front but again I'm just not sure so any advice and tips will be greatly appreciated, and I just want to make sure every option and avenue is covered!

Thanks!

Tsaani97xj

Drive line angles are off.

Best option: SYE, shims, CV driveshaft

Option: TC drop, shims

The grinding/buzzing is out of phase driveline.

People claim to get away without any of that at various lift heights but it has always been my experience that you HAVE to adjust your driveline when you lift.

Best.

sheffeaj

Tsaani97xj,

Thank you for the quick reply!

I do have some more questions though:

For the best option that you presented, can you give me more details on each part i.e. what SYE would potentially work best (brand, hack-n-tap, ect.), what shims to use (what part do I search for) and if the CV driveshaft is front or rear?

Ive done a little other reading about the CV driveshaft and I'm seeing a good amount about the rear one being the issue, but I just want to make sure (huge price difference). Or do I need to replace both? Would I be able to use a SYE without the CV driveshaft?

Also what do the shims do exactly? How do they work, where do they go ect. Im new to modifying jeeps and am trying to learn my way around it.

Thank you for your time.