unstable street driving with lift?...please help! - JeepForum.com

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post #1 of 30 Old 08-27-2013, 07:24 PM Thread Starter
rixter
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unstable street driving with lift?...please help!

Newbie here.....

6 months ago I purchased my first CJ, a 1981 CJ7. Ive owned many TJ's and 1 YJ prior without the problems I will mention........

I recently had a 4" Rough Country lift installed on 33x12.5 tires, with 1.25 spacers on rear only (narrow track axle)

My question is.....Is it normal to have instability driving at 40-50 mph??
Alot of over correction, and I wont attempt the freeway. Alignment was done and is perfect as it can be, steering has no slack, tire pressure is fine. Is it the quality of the lift kit, springs, height etc???? If I keep a wider track on the front will that help..say...2" spacers on the back, and 1.25 in the front?? Should I/Can I, lower it a bit for better center of gravity, and can I modify the springs I have now?? The Rough Country stiff ride isnt what I was looking for (huge regret/) as my "rig" is strictly a road queen, and developed a mud allergy the day I bought it.

Looking forward to your replies. Have a look at my pics

Cheers

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post #2 of 30 Old 08-27-2013, 07:37 PM
Waldomas
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How long are those front spring shackles?

Too long will allow the axle to shift back and forth making turning a little hairy.

I would get them as short as possible (3" center to center).

Also go at least 3/8" thick.
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post #3 of 30 Old 08-27-2013, 07:39 PM
Waldomas
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Sweet 7 by the way.

Are those 33s or 35s?
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post #4 of 30 Old 08-27-2013, 08:20 PM
Matt1981CJ7
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I'd question that "perfect as can be" alignment.

What did your caster measure?

Matt
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post #5 of 30 Old 08-27-2013, 08:48 PM Thread Starter
rixter
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4 inch shackles, and I don`t know the exact castor measurement, but I was told it was slightly off at the time. It was done by a reputable and recommended tech. Also forgot to mention in my original post....the drivers side seems to be sagging. Take a look at the pic from the front, its alot more prominent in person though. Could the sagging cause some driving headaches
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post #6 of 30 Old 08-27-2013, 09:10 PM
Matt1981CJ7
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Your CJ appears to have the infamous "Jeep Lean". It was a factory f-up that resulted in a number of CJs being sold with twisted frames. At the time, AMC sent out a recall notice on it. Their fix was a 1/2" shim between the rear passenger spring and spring perch.

Search "Jeep Lean" and you'll get plenty of info on it.

Your caster should be 5-7 degrees positive. Anything less than that and your CJ will wander like a lost child.

Good luck,

Matt
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post #7 of 30 Old 08-27-2013, 09:21 PM
WindKnot
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"Slightly off"?

Toe In should be 3/64 to 3/32 inch (1.19 to 2.38mm)

Camber is 0° and can't be adjusted. Wheels have to be vertical. If it's off, you get to replace parts.

Castor is +6°. Adjust with tapered shims between the pad and the spring.
This is the measurement that almost always gets screwed up with a lift. If it is "slightly off", fix it.

What tires are you running and what is the inflation pressure?

I'd rather be lost on the trails than found at home!

Phoenix Rising- A Flame Off Restoration? http://www.jeepforum.com/forum/f8/ph...ation-1807257/
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post #8 of 30 Old 08-27-2013, 09:39 PM Thread Starter
rixter
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thanks for the info Matt

Windknot- im running goodyear duratracs at 30 psi. ill get a second opinion on the alignment. thanks
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post #9 of 30 Old 08-27-2013, 09:53 PM
Jack61
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Have all the axle u-bolts been re-torqued after the lift install?

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post #10 of 30 Old 08-27-2013, 09:55 PM Thread Starter
rixter
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Hey Jack, no they havent. im assuming they should. thanks
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post #11 of 30 Old 08-27-2013, 10:03 PM
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Yes sir,absolutely, they can loosen a fair amount in the first few miles of driving.
Edit: also check the torque on those rear adapters. When I built my rear axle I widened it to the same track width as the front, no instability

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post #12 of 30 Old 08-27-2013, 10:08 PM
LumpyGrits
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Get it to an alignment shop PDQ.
The front end must be brought back into spec.
LG

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post #13 of 30 Old 08-27-2013, 10:30 PM
WindKnot
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I'd consider dropping tire pressure a bit. Who came up with 30psi and how? The stock set up only wanted about 25lbs. Overinflating your tires can make them squirrely. See if lowering the TP helps. But pay attention to what's being said about the alignment! The engineers at Jeep really did know what they were doing when they set up the original geometry in the suspension and steering. You changed it when you lifted it. It HAS to get back into spec. Lifting a Jeep is more than changing springs.

Also, the rear axle is usually narrower than the front to aid in handling. Why the wheel spacers on the rears, and are they now wider than the fronts?

I'd rather be lost on the trails than found at home!

Phoenix Rising- A Flame Off Restoration? http://www.jeepforum.com/forum/f8/ph...ation-1807257/
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post #14 of 30 Old 08-28-2013, 08:29 AM
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at least do a redneck alingment before you drive it again with broom sticks or 2x4's or something. What I thought was "close" by eyeball was actually WAY toe in. my measurement 6" off the front and back of the tire was so far off i had to put about 3 full tuns into the tie rod to even get it within the same inch as each other.

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Quote:
Originally Posted by twoleos617 View Post
To reiterate for the 1,067th time, when towing...
remove rear axle, xfer in N, trans in 5th, remove neg batt cable, key to Run and go??
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post #15 of 30 Old 08-28-2013, 10:17 AM
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Did you get a drop pitman arm with the lift?

1980 cj5 401, t-176, p/s., YJ p/b, tfi/hei hybrid, 3.73 30/44
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