The lift on my tj right now came with 1 inch transfer case drop spacers, and only replaced the lower control arms for the front and back. I had the SYE kit added and a pair of adjustable upper rear control arms added so I could get rid of the spacers and adjust my pinion angle. It has a cv driveshaft also added. I've had vibrations at high speeds ever since an accident a couple years ago and have been adjusting the pinion angle ever so often to figure out a good spot.
Does anyone who lurks around here in the group actually have a 4 inch lift and mess around with it? I'd like to hear what kind of setup you have and how its riding and such. I'm considering getting rid of this lift kit if I can't get it running smoothly at high speed.
You might also try an adjustable rear trackbar to bring your rear axle back into place, laterally. However, you didn't mention if the accident was before or after the lift. Vibes due to accidents open up a whole can of worms...could be a bent rim, bruised tire, tweaked anything...etc. Are you SURE it is a driveline vibe??
Ah I didn't think about the rear trackbar... I had drilled a hole in the bracket for the front bar to adjust it and didn't do the back. That would straighten out my driveshaft, I noticed it was a little to the left... The vibes started after the accident. I spent an hour under there the other day looking and grabbing parts and shaking and thinking.... and I think the lift I bought is just crap.
The lower arms that came with the kit aren't adjustable... I think it was designed so it HAD to have drop case spacers or need adjustable control arms for the lower, which it didn't. So I guess since I know now what I didn't then, can anyone recommend a long arm suspension for my TJ? 4 inches please
Describe your vibes. When do they occur (rpms, speed, acceleration, deceleration? If this started just following an accident, I think it is unlikely that these are driveline vibes.
2003 TJ Rubicon * 2001 XJ Sport * 1971 Bill Stroppe Baja Bronco
"There is a very fine line between 'hobby' and 'mental illness'."
Pronunciation: 'jEp Function: noun Date: 1940
Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase') A small general-purpose motor vehicle with 80" wheelbase, 1/4-ton capacity and four-wheel drive used by the U.S. army in World War II. _____________________________________________________________________
Well the accident was right after I got out from getting the locker and new gears put in. I had them remove the one inch spacers under the transfer case also. I didn't get it that fast to see if anything was done wrong. I also noticed that the front pinion was leaking a very little... so today I dropped the case back down using the one inch spacers and adjusted my control arms back so the pinion faced the output shaft again. It's gotten alot of the vibrations out now but I notice the shaft isnt' perfectly straight when viewed from below.
So all this makes me think of getting adjustable arms all around and an adjustable rear track bar to get it straightened out. Does that sound like it would work or maybe I should just get a new kit altogether.
You still haven't described at what point you are feeling vibes. This is helpful in determining whether or not these are actual driveline vibes you are feeling. A timeline of what you changed, including the accident, would also help.
There is no reason that you would need a SYE w/ CV driveshaft AND the transfer drop kit with a 4" lift. Lose the drop kit. Make sure you adjust your rear pinion angle for a CV shaft, not your stock shaft. Once you lower the Jeep to the ground, recheck your pinion angle as the weight of the Jeep on it's suspension will change the pinion angle slightly. Check your front pinion for excessive angle (when aligning the front end, pinion angle should take precedent over camber). Make sure your driveshafts are balanced.
You also should be able to get the shaft/pinion angle in line with just the upper adjustable control arms. If you have driven the vehicle a lot with major driveline vibes, you may have damaged your u-joints.
2003 TJ Rubicon * 2001 XJ Sport * 1971 Bill Stroppe Baja Bronco
"There is a very fine line between 'hobby' and 'mental illness'."
Pronunciation: 'jEp Function: noun Date: 1940
Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase') A small general-purpose motor vehicle with 80" wheelbase, 1/4-ton capacity and four-wheel drive used by the U.S. army in World War II. _____________________________________________________________________
I start noticing them now at around 45mph, then at 65-70. Much better though than before. I was under again today and looks like I do need the adjustable trackbar to get the rear driveline straight. I would like to get rid of the spacers but I'm gonna hold off until I get the trackbar, and probably some new adjustable control arms for the front since it has a cv driveshaft also but no pinion angle adjustments. With the case lifted it pointed straight back instead of to the shaft. Had the tires balanced and rotated today also. It's not my daily driver luckily so ujoint damage isn't great hopefully.
I remember reading in a post that in my setup the angle of the rear pinion should be towards the output shaft, but with 1-3 degrees up for axle wrap, is this correct?
Hold off on the rear trackbar for a bit. Let's see if you can dial it in as is, first. I would definately lose the drop kit. You simply do not need it with a quality CV shaft. (Tom Wood makes a nice one)
Try this...drive the Jeep to the speed you feel the vibes starting and hang around that speed for this test. Just cruise and slowly accelerate and decelerate through the vibes. Concentrate on when you feel the vibes. If you feel the vibes on acceleration only, your pinion is pointed too high, if on deceleration only, it's too low. They should go away at 'coast' and not be present at both 'acceleration' and 'deceleration' if they are pinion angle related. If they don't, you have another issue and it is probably not your pinion angle.
Now, I didn't realize you didn't have ANY adjustable control arms up front. Yes, you need those to properly set your camber, or get it closer to stock specs. If your camber is too vertical, you may feel the Jeep wandering or odd steering corrections. Also, if your front driveshaft is at too much of an angle, you can cause vibe problems. You also might remove the front driveshaft to eliminate it, or pinpoint it, as the culprit.
2003 TJ Rubicon * 2001 XJ Sport * 1971 Bill Stroppe Baja Bronco
"There is a very fine line between 'hobby' and 'mental illness'."
Pronunciation: 'jEp Function: noun Date: 1940
Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase') A small general-purpose motor vehicle with 80" wheelbase, 1/4-ton capacity and four-wheel drive used by the U.S. army in World War II. _____________________________________________________________________
This is Troy, I'm using my brothers account since my tools are at his house.
I kept the spacers on for now, and adjusted the rear upper control arms correctly for the pinion angle, since I dont have adjustable arms up front. So things are where they're kinda supposed to be, and now I can get up to
70mph without major vibes. But now something else comes to mind.
This lift I have is just crappy, I wouldn't recommend it to anyone. That being said, when it was lifted it didn't come with an adjustable track bar so my d30 was sitting a little bit to the left. The store that I bought the lift from, and who installs them (they didn't install mine) said to drill a hole in the track bar bracket (on the axle) about 1/2 of an inch iirc to adjust for the change. I haven't had a problem with it so far. Now I'm wondering if the same should be done to the rear track bar's bracket? There's not much of a noticable difference in the way it sits since the lift came with a bracket for the rear track bar, however when under the jeep I look up at the rear driveshaft and notice it's not straight... it's sitting to the side a little bit. How much is a little I can't exactly say but its definately noticable. Could the vibes be coming from the sideways slant? I suspect they are.
I checked out the bracket and there's room for me to drill another hole and move the bar to the side enough to center the rear axle, I just wanted to check with everyone here to see if their rear shaft is straight when viewed from the bottom.
They make a bracket for that so you keep the structural strength and flex angles. You can try the new hole, but be aware you might have to do some fixing later if it tears through. That part has a fair bit if stress on it.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
2003 TJ Rubicon * 2001 XJ Sport * 1971 Bill Stroppe Baja Bronco
"There is a very fine line between 'hobby' and 'mental illness'."
Pronunciation: 'jEp Function: noun Date: 1940
Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase') A small general-purpose motor vehicle with 80" wheelbase, 1/4-ton capacity and four-wheel drive used by the U.S. army in World War II. _____________________________________________________________________
Yes, sorry I didn't mention that. It has a bracket that adjusts for the height of the lift. I was looking at it and there isnt much space for another hole, but the bracket on the frame of the jeep has enough space. I crawled under my girlfriend's tj when she got home and looked at her driveline from underneath but it was getting dark, although I think it is over a little but not as much as mine. It might just be my imagination that the axle is over a little. How can I tell the rear end is where it's supposed to be?
Oops I did forget to mention that I have a bracket that came with the lift for the rear track bar... Its still the factory trackbar though. I posted an answer to Mike about what else I looked at under there. I'm just getting tired of checking this thing out on my own, lol. I called a shop today in town and although they're on the other side of town I was considering taking it to them and just shelling out the bucks for them to figure it out. I just have the feeling there's something I'm missing, and I hate to give up but looks like I've fumbled onto something I just don't have the experience to fix. Although I would try anything you guys suggested. I've got a couple weeks before my appointment. I haven't gotten to taking off the front driveshaft to test yet but if you think I should then I will. Otherwise I'm just gonna let it sit until they can look at it.
Ok I will do that tomorrow. I'll remember to mark it where it goes also, I read somewhere that if you put them back on out of phase or something like that it'll make things work.
Out of phase is pretty hard to get to unless you take apart the driveshaft. The u-joints need to be lined up so if you sit the driveshaft on the ground and the front u-joint lifts up pivoting on the driveshaft, then the back one has to lift up also pivoting on the driveshaft, not move sideways. Or the 'ears' the u-joints fit into on the driveshaft have to be parallel, not one end level with the ground and the other end vertical.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Right now, my rear end isn't where it's supposed to be. I can tell this because one wheel physically sticks out past my flare and the other is slightly inside the flare. My front is slightly screwy too.
In my case I also have clutch linkage issues which led me to go looking for the trouble....
My body has shifted on the frame though. I have to sit it under a big tree with a winch on the roll bar to lift it and loosen the body bolts to square it back up.
So where exactly did you get hit in this 'accident'?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
I was on a one way two lane road, making a left turn from the right lane. The left lane car should have been making a left turn also but he went straight and hit me square in the side as I was turning left. His car was a little pos and went under my jeep. Luckily he hit my step bars under the door, cuz I didn't get any body damage, but it pushed me sideways (from the left) into the curb on my right where I came to a dead stop. The right side of the rear end hit the curb and stopped me, bending the rear end up so I got a factory new one under there. Possibly the bracket being pushed so hard by the weight of 2 vehicles got a tad bent over? Or maybe the track bar folded a bit? I don't know. I'm gonna look around for that stuff again today.
I'm about to go remove the front driveshaft and see if the vibes are from that or not. I'll let ya'll know what happens!
Wait, instead of removing my front driveshaft couldn't I jack up the rear end, support it with jackstands and remove the wheels putting the lugs back on to keep the drums on and put it in gear to find vibes that way? Or should I just take off the front and street drive it?
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