What would cause a serious wobble in the rear end?

Just to confirm what you are seeing because this term is commonly used for a shaking in the front end but not in the rear.

So, when this happens, are you driving at highway speeds and hitting a joint in a bridge or something else in the road and the steering wheel starts shaking until you slow down?

If so, then this is an issue in the front end and not the rear.

This can be anything from tires to tie rods. However, the most likely cause is a weak steering dampener.

Have you replaced this and if so, can you give a list of things that you have replaced at the front end?

This issue can happen on any twin I beam suspension, so we need to run through the most common things first.

This includes shaking down the front end and finding out if we have loose tie rods or other steering components.

https://www.2carpros.com/articles/steering-wheel-shakes-when-accelerating-or-braking

https://www.2carpros.com/articles/tie-rod-end-replacement

Please let me know about this info and we can go from there.

Thanks

Okay. That just means it is a worse issue than others because it doesn't have to happen only at highway speeds.

So, if this is a shaking of the steering wheel then we can fix it, but I need a full list of what you have replaced. What is "everything?"

Also, we may end up redoing things because this issue is normally only a couple things so let's just provide this detail and go from there.

Lastly, because you have a lift kit, which is going to aggravate this issue. Did you just install this lift, or has it been installed for a while?

Have you done anything with the tires on the front? Have you rotated them to the rear?

Okay. If it were me, I would rotate the tires and just make sure you don't have a weak side wall that would cause this. However, I suspect it is a steering dampener issue.

I would replace the steering dampener with an updated and larger dampener. Since you have a lift kit on the vehicle, you have altered the steering angles and so the stock dampener cannot handle the added load due to different angles and so they wear out quickly.

I would remove it and see if you can press the ram in and out by hand. If you can then it is worn out.

However, if you are going to take it off, I would just put a new one on since you can get a really good one for not much money.

Here is a link to the one I would use:

https://www.summitracing.com/parts/sja-7009/make/jeep/model/grand-cherokee

Please run through this and let me know what you find. Thanks