Control Arms Suspension Cycle & Bump-Stop

Landon

Landon

TJ Enthusiast
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Nov 24, 2018
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Location
Conroe, TX
Good evening,

Today while reading Kevin’s thread on adj control arms I had an “oh shit” moment. Now I don’t have a tt but I did stumble my way through installing Currie’s lift package about 18m ago. Before that project I had never turned a wrench in my life but had some family help with the project. I managed to fumble through an SYE install and set the rear driveshaft angle. Back to my epiphany.... I realized I never cycled my suspension, checked bump, or bump alignment, and I certainly didn’t follow the well written how to on aligning axles and setting CA lengths. https://wranglertjforum.com/threads...-control-arms-on-a-jeep-wrangler-tj-lj.17062/ I should mention I had the Jeep aligned after all was “complete”. I have some minor vibes between 30-45mph the alignment shop said they couldn’t fix, sound familiar???

My questions to the community are, what am I about to get myself into? I have time over the holidays and would like to know my Jeep is done right. Are there other how to guides I should study before jumping into this? Am on the right track with my goals below? Where should I start? I’d like this thread to my go to for support.

My goals are:
1. Set bump to protect shocks
2. Set bumps for tire and fenders and any other clearance issues
3. Center axles and redo / check control arms
4. Get rid of vibes
 
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Things I wish I knew when I first set my bumps.
When setting bumps to protect your shocks you set them with axle at full bump meaning the whole axle is jacked up. This is because in real life the axle only reaches full bump at a high speed which is why you have to protect the shocks. Don’t worry about the shocks bottoming during side to side articulation because during articulation the axle will be moving slow so the shock can handle being the bumpstop in this instance.
You do need to check for tire interference during side to side articulation and make sure the tire isn’t running into metal. Don’t worry if it runs into plastic flares as long as it’s not hitting metal you are good.
 
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One thing folks forget is bump stops also protect the opposite shock...keeps them from getting torn off when you stuff one side.
 
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scratchin my head here too, i'd like to hear an explanation of the idea behind that 1.
 
someguysjeep said:
scratchin my head here too, i'd like to hear an explanation of the idea behind that 1.
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Maybe I'm wrong...I was wheeling with a guy with no bump stops and he stuffed a wheel and the opposite side stressed and tore the shock off.. I thought that is caused /contributed to it. I understand it can flex down regardless.
 
AndyG said:
Maybe I'm wrong...I was wheeling with a guy with no bump stops and he stuffed a wheel and the opposite side stressed and tore the shock off.. I thought that is caused /contributed to it. I understand it can flex down regardless.
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He might have had the wrong bushings.
 
jjvw said:
He might have had the wrong bushings.
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Man have I done something to offend you. All I do is try to get on here and learn,. Share things that have worked for me... And have a laugh or two.

I never said I was right about everything. as a matter of fact I got married because I was tired of being right all the time.
 
AndyG said:
Man have I done something to offend you. All I do is try to get on here and learn,. Share things that have worked for me... And have a laugh or two.

I never said I was right about everything. as a matter of fact I got married because I was tired of being right all the time.
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Were the shocks too long?
 
jjvw said:
Were the shocks too long?
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I would think too short. The leverage the stuffed tire put on the opposite side could have possibly don that. Could also have been caused in concert to a too short track-bar... the leverage may have shifted the axle too far to that side, binding the shock and tearing it off. Most likely a "Perfect Storm" of issues... all causing the shock to bind.
 
Artsifrtsi said:
I would think too short. The leverage the stuffed tire put on the opposite side could have possibly don that. Could also have been caused in concert to a too short track-bar... the leverage may have shifted the axle too far to that side, binding the shock and tearing it off. Most likely a "Perfect Storm" of issues... all causing the shock to bind.
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If it was too short, the shock acts just like a limit strap the way most do. Plus, if the shock was too short, then the thought of the bumps being long enough would not be a consideration.

Too long of a shock can break a lower mount due to not enough up travel to slow the travel speed before impact. Longer bumps are a bandaid fix for this, if the bumps are the first point of contact. Either way, the shocks are too long.
 
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Artsifrtsi said:
I would think too short. The leverage the stuffed tire put on the opposite side could have possibly don that. Could also have been caused in concert to a too short track-bar... the leverage may have shifted the axle too far to that side, binding the shock and tearing it off. Most likely a "Perfect Storm" of issues... all causing the shock to bind.
Click to expand...
It isn't possible for the stuffed side to rip the other side shock loose under any circumstance that would allow a shock to remain viable long enough to get it off of the trailer.
 
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jjvw said:
If it was too short, the shock acts just like a limit strap the way most do. Plus, if the shock was too short, then the thought of the bumps being long enough would not be a consideration.
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But if once it reached it's limit, and then was forced sideways with axle shift due to a short TB?
 
Artsifrtsi said:
But if once it reached it's limit, and then was forced sideways with axle shift due to a short TB?
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Then someone really screwed things up by going out of their way putting that short track bar in.
 
Pull springs, set axle to full bump, adjust lower arms so that axle is centered to the lower perch at full bump.
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Now check the track bars for clearance issues. Front needs to clear the diff cover and not hit any steering components. Rear track bar needs to clear the gas tank skid, and the TB relocation bracket needs to clear the tub. If they hit, add bump stop extension until they don't. Check shocks at full bump to make sure they aren't bottoming out. If they are, add bump stop, or measure the shocks to get the correct length shock. Put wheels back on and go to full bump to make sure tires aren't hitting metal. Turn front wheels lock to lock and articulate each side and check for clearance. Once you have that done and have the springs, wheels back on, it's time to check to see if the axles are centered side to side. Adjust track bars accordingly. You'll need to check alignment again.
 
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