I got questions, who has answers?

B

Box kicker

NAXJA Forum User
Location
Cherry Point, North Carolina
Okay so today I installed my Quadratec HD springs on my 2000 XJ sport 4.0L. On top of that I have teraflex 2'' shackle and spacer lift kit.

1.) I obviously need new shocks to accommodate the new found height on this Daily Driver. What are recommendations on shocks? I was going to go with Rough Country shocks for their affordability, what kind should I get? +4? +3? there's no crazy off roading done in this XJ.

2.) It rides REALLY rough and I feel every pebble and bump in the road, what can I do to smooth things out so I'm not bouncing up and down every time I kill an ant?

3.) When I hit 20 mph until about 35 mph I have a really loud vibration that makes me look like a mobile vibrator. What is it if you know? or what is the most likely cause(s) of this tremor?

4.) When I press the gas or let off a bit I get a grinding noise with a vibration when I'm driving down the road. What could this be?

I am not too good at building jeeps obviously because this is the first vehicle that I'm building beyond stock so I appreciate any help pf the vast experienced expert XJ builders. Please if you could give answers with the numbers next to them so I don't get confused. all that vibrating and bouncing around has made me dizzy with a headache.
 
Box kicker said:
Okay so today I installed my Quadratec HD springs on my 2000 XJ sport 4.0L. On top of that I have teraflex 2'' shackle and spacer lift kit.

1.) I obviously need new shocks to accommodate the new found height on this Daily Driver. What are recommendations on shocks? I was going to go with Rough Country shocks for their affordability, what kind should I get? +4? +3? there's no crazy off roading done in this XJ.

Personally, if it's a DD I'd put it back where you had it and drive it. What's the point in lifting it to the sky if it stays on the highway?

2.) It rides REALLY rough and I feel every pebble and bump in the road, what can I do to smooth things out so I'm not bouncing up and down every time I kill an ant?

You'll have that with a taller lift and short arms. If you're set with the lift height then I'd suggest you look into some control arm drop brackets. They're fairly affordable these days.

3.) When I hit 20 mph until about 35 mph I have a really loud vibration that makes me look like a mobile vibrator. What is it if you know? or what is the most likely cause(s) of this tremor?

SYE. I'd guess it's a drive shaft misalignment. Check out your pinion angles.

4.) When I press the gas or let off a bit I get a grinding noise with a vibration when I'm driving down the road. What could this be?

Pinion angle...

I am not too good at building jeeps obviously because this is the first vehicle that I'm building beyond stock so I appreciate any help pf the vast experienced expert XJ builders. Please if you could give answers with the numbers next to them so I don't get confused. all that vibrating and bouncing around has made me dizzy with a headache.
Click to expand...

Good luck.
 
Box kicker said:
Okay so today I installed my Quadratec HD springs on my 2000 XJ sport 4.0L. On top of that I have teraflex 2'' shackle and spacer lift kit.

1.) I obviously need new shocks to accommodate the new found height on this Daily Driver. What are recommendations on shocks? I was going to go with Rough Country shocks for their affordability, what kind should I get? +4? +3? there's no crazy off roading done in this XJ.

2.) It rides REALLY rough and I feel every pebble and bump in the road, what can I do to smooth things out so I'm not bouncing up and down every time I kill an ant?

3.) When I hit 20 mph until about 35 mph I have a really loud vibration that makes me look like a mobile vibrator. What is it if you know? or what is the most likely cause(s) of this tremor?

4.) When I press the gas or let off a bit I get a grinding noise with a vibration when I'm driving down the road. What could this be?

I am not too good at building jeeps obviously because this is the first vehicle that I'm building beyond stock so I appreciate any help pf the vast experienced expert XJ builders. Please if you could give answers with the numbers next to them so I don't get confused. all that vibrating and bouncing around has made me dizzy with a headache.
Click to expand...

For #2-4 I agree with Lowrange. Get a slip yoke eliminator kit, drop brackets, an adjustable track bar, and set your rear axle pinion angle correctly.

For #1, what is your total lift height? I went with stock JK Rubicon or X shocks. I had my local 4x4 store let me know when a new JK owner had them do a lift and was going to scrap their OEM shocks. I picked up a set of 4 with under 100 miles on them for about $20.
 
I put on new leaf packs because the old ones were shot. they were sagging the wrong way so I might as well get something sturdy. I'm not jacking it up anymore than it is right now as the rear end sits. I think it's tall enough already I would rather just level it out to make the front end even with the rear. so a SYE would change the pinion angles?

it's only between 20-35 mph. any other speed it's smooth so that's why I was wondering what was going on.

I know this sounds dumb but aren't control arms just for the front? or do the rear ones have them too? because I only changed the height of the rear. the front end is still sitting with spacers. like I said the height will change one more time when I level the front end to the back end height.
 
Hmmm,

I wouldn't think the mild lift would effect the angles to bad but i'd suggest you check them out either way.

You at least want the pinion pointed at the T-case.
 
I'm running the same exact set-up on my DD 90XJ. I have a set of quadratec HD springs with the "eyes" cut out and bastard packed to the stock main spring and I'm running 2" shackles. I'm at about 2-3/4 lift front/rear.

I recommend Nitro-Charger shocks, the stock height will work at 0-3" lift and the ride smooth-ens out nicely over the Rancho's I had on there.

You need a SYE, I'm running a Advance Adaptors on mine with a Tom Woods shaft and corrected pinion angle.
 
Box kicker said:
bastard packed? you lost me there. well from what I heard nitro shocks were for more off road capabilities while regular oil was for multi purpose. is a SYE hard to install? so a tcase drop won't solve anything?
Click to expand...

Bastard packed just means I used two different leaf packs mated together. A T-case drop might help but you will have to adjust the pinion angle as well. When running a slip yoke style driveshaft the pinion and the output shaft must be on the same angle, if an imaginary line is drawn through both angles, the lines will never intersect(the lines would be parallel). On a SYE/double cardain driveshaft you point the pinion straight at the out put shaft on the T-case. Two very different set-ups.
 
Cottontail said:
For #2-4 Get a slip yoke eliminator kit
worth it's weight in gold on 96+ XJ's
drop brackets
these drop your control arm mounts about 4"-- won't really help at 3" lift
and set your rear axle pinion angle correctly.
1*-2* below the transfer case angle should be your goal
Click to expand...

once everything is leveled out, get a quality alignment done at a reputable shop and request a copy of the printout when they're done-- if all is good afterward, you have the specs to tell someone else how to align it next time.

I would also make sure (or just replace) all the u-joints are in top notch condition as lifting or changing pinion angles will cause the joints to operate at a different angle-- this can reveal a previously unnoticed worn joint.
 
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ok so i know this guy and i know his jeep. he has a BB on it and some new HD oem packs. this jeep has seem some off roading i know, but what i dont know is if his u joints have ever been gone through. i dont think a SYE is necessarily the next step for this rig with as little lift it has.

does anyone else think maybe the joints in the rear might be the cause? seems liek the cheapest thing to start with
 
Timmy2XJS said:
ok so i know this guy and i know his jeep. he has a BB on it and some new HD oem packs. this jeep has seem some off roading i know, but what i dont know is if his u joints have ever been gone through. i dont think a SYE is necessarily the next step for this rig with as little lift it has.

does anyone else think maybe the joints in the rear might be the cause? seems liek the cheapest thing to start with
Click to expand...

Yes, throw some new U-joints in there. They are cheap and easy to do. Then see if the bad vibs go away.
 
Timmy2XJS said:
ok so i know this guy and i know his jeep. he has a BB on it and some new HD oem packs. this jeep has seem some off roading i know, but what i dont know is if his u joints have ever been gone through. i dont think a SYE is necessarily the next step for this rig with as little lift it has.

does anyone else think maybe the joints in the rear might be the cause? seems liek the cheapest thing to start with
Click to expand...

The noise change on deceleration definitely points to u-joints. Most driving between 20-35 mph is on the gas, off the gas. That identifies a loose joint in a vibration because you're running on different sides of the cap when you're accelerating and decelerating. Chances are that when he gets to 40 mph, he's probably in a steady speed and the joint doesn't vibrate.

Although, with as little information as he's provided and the jist of his posts, I'd guess that he's not very mechanically inclined. He might want someone who knows what they're looking at to make sure that everything is installed correctly. A loose u-bolt or some extra axle movement will make for an expensive day in the future.
 
RedHeep said:
Although, with as little information as he's provided and the jist of his posts, I'd guess that he's not very mechanically inclined. .
Click to expand...

hes a good kid and hes learning his rig the best he can. i know he came to this wonderful site mostly because of the NAXJA stickers on my rigs ;) and i know he thanks yall

poor kid all hes got is me on hand to help him! lol
 
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Timmy2XJS said:
hes a good kid and hes learning his rig the best he can. i know he came to this wonderful site mostly because of the NAXJA stickers on my rigs ;) and i know he thanks yall

poor kid all hes got is me on hand to help him! lol
Click to expand...

Hey, we can talk you and the kid through a engine rebuild if you need us too! Most of us on here have fixed or touched every nut or bolt on a XJ.
 
WOAH WOAH WOAH! I am inclined to routine maintenance. I've never done a build though. I don't know the processes of upgrades. and yeah the vibes go away at 35 mph then it's smooth. I hear minor grinding on acceleration and deceleration. like a quick noise. Tim has helped me and talked me through a lot, but I've done all the upgrades at friends houses who have done this before too! but yeah I do appreciate everyone of you who helps me with the tech support cuz it's complicated in my head until you guys give simple answers that I can understand! and I didn't learn about this from the naxja stickers on his XJ, I learned it from the post it he gave me saying here's a good place for info! hahaha
 
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