I think I have it solved. No driveline vibes, and only minor vibration. The vibes seem to get less and less the more i drive.

Here is my theory. I drove years with my lift (lets say 2-3" but closer to 2) with no probs. I had to drop the TC on account of new rear leafs. This put added pressure on the motor mounts, and maybe the tranny mount. Causing the shuddering. The new tranny mount is MUCH more rigid, and made the vibes worse at the motor mounts. When I replaced the motor mounts I raised back up the TC and shimmed the axle, hoping I got the angles right. Well, though I measured, it didn't quite work. So I ended up with some vibes. I Dropped the TC again, no vibes, and the vibes/shuddering from the mounts are improving. I think the new mount rubber is "settling in" or maybe softening up a bit as I drive.

As far as the TC and a SYE, it just isn't reasonable for me to spend that cash now. I only lifted my jeep to get biger tires to keep my diffs from hitting the sand/rocks on the beach where I surf. The road can get rutted. With this configuration I have had no trouble at all. I do understand the SYE and why it helps, but If I can go another 10yrs with no probs, im ok with this set up.

I was really surprised to find my tranny mount in such poor condition, I never would have suspected that if it wasn't for this forum. Thanks.

 

Awesome!^ I have bad shakes on moderate accelerations (from stoplights) and my springs are super bad...I've been hoping they'll go away or get better when I get my new leaf springs!

Edit: That message was for gstraniere, but I'm really happy for you, too!

 

I see a number of posts about vibes and whatnot only under hard acceleration. Not that this is your problem, but there is one cause that I think gets overlooked because on lifted XJ's most peoples' first thought is pinion angles/yokes/mounts/etc.

A failing torque converter. I knew a guy who had the problem and spent forever trying to track down the issue. When his TC failed an he had to replace it, guess what? His other problem went away too!. Another guy just gave his trans a forward flush to get all new fluid in there (the old stuff was BLACK and smelled like death), including in the TC, and his shudder under hard load went away.

 

Hmmm...interesting. thanks for the info...hope mine isn't like that, as im not mechanically inclined...

 

My problem is solved after an alignment and tire balance yesterday btw. Alignment was way off tho(ridicolously off), so it might have just been affecting a part which caused the vibration. Maybe in your case, that part is shot and alignment is good, maybe not. But alignment is a cheap thing, give it a chance.

 

I understand that but what many people fail to realize is the Jeep doesn't care what simple reason you have for lifting it. All it cares about is that you lifted it and now the geometry is all screwed up. A SYE and a drive shaft costs as little as $175. You'll spend that much in motor mounts and chasing vibrations from your TC drop over the next 10 years.

Either way, you aren't the only one that'll opt for the cheap route. Hell, 75% of XJ owners are cheapskates that cut every corner possible.

I hope it lasts you well.

 

Where are you?

 

Just put a surfboard rack on the drive shaft. That'll fix it.

 

^ Words of wisdom for every thread regarding SYE versus TC drop!
Hack it or Crack it, just do it..SYE

 

True but the fact is that people need to learn the LAW of CAUSE and EFFECT. A night of reading this forum prior to any work on the Jeep, and avoiding shortcuts would have completely prevented this whole thread. And that the purchase of a $2 angle gauge from harbor freight would have save hours of changing parts.

 

I'm not sure if this is meant to be helpful or not. And the following is only intended if your post was directed to me specifically, as I do believe in most cases you are right.

I realize my jeep doesn't care why I lifted it, but I went 10yrs with no vibes, or adverse effects related to the TC drop. So have many others. In 14 years of ownership, I replaced 2 motor mounts once, and 1 tranny mount. If you know the cost of those parts, you would know I spent nowhere near 175. Not that that's very expensive, but its for something I just do not need. I would have needed to replace the mounts anyway.

I didn't opt for the cheap route, I opted for the proper route to accomplish what was required for me to enjoy my jeep. I hope the 75% of us labeled as cheapskates are as offended by that statement as I am.

 

SteveMongr: Im on eastern Long Island

 

Reading this whole thread would have avoided you from posting your comment. As I stated, I did buy a tool to measure the angle, cost 8 bucks off amazon, sorry, I didn't get it from harbor freight, maybe that's what went wrong. I measured the angle (again, read the whole thread) and maybe messed it up a bit, or was just slightly too much with the shims. God forbid I made a mistake and learned something.

I understand the Law of cause of effect, and am learning how it applies to my jeep by working on it myself, making mistakes, and asking for help. Please be specific and detail the shortcut I took please. And please do not say a SYE, as it is now and was always needless for me.

 

I'm gonna look into this, and thank you. I still have some vibes, not related to the driveline. It seems to be diminishing, but this is a good bit of info to check in to....thank you.

 

It was meant to be helpful. Everything I post is meant to be helpful. It may be blunt but it's helpful.

T-case drops are the cheap route. It's a fact. There is nothing "proper" about a t-case drop. It causes 5 more problems than it solves.

You DO need a SYE. If you didn't need a SYE then you wouldn't have started this thread. That's also a fact.