Lowered Cognito Lift bottoming out

TowU4Free

#SecretSquirrel
Aug 27, 2011
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Norcal truck and or Norcal Nick. I need some advice here. I am running the Cognito as you know. and im running with no blocks in the rear with lowering keys. (Mind you, this makes the front sit about an inch or so lower than stock keys with no turns on bolts. So i have the jouncers cut to about 1/8-1/4 space before they touch. Problem im having is when i hit a bump in the road the suspension feels as if it bottoms on. like chatter your teeth hard ! I unbolted the shock at the bottom yesterday and pushed it up to see how much travel is there. ( have pics waiting for my friend to send them) It looks like i have about an 1 1/2 inches of travel up for the shock. I bounced the truck up and down while this was unbolted and the eyelet on the shock never came down far enough to match the eyelet on the bracket (thus telling me it wasnt moving enough to bottom out) Now i guess my question is. Does the suspension really travel more than that? And should i put the Z71 jouncers in and trim them less so that the suspension is sitting on them? Or will that cause a harsh ride?. Do i need a different shock? Is the Rancho RS999288 too long? Its the same shock i was using when the suspension was stock.
 

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Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Norcal truck and or Norcal Nick. I need some advice here. I am running the Cognito as you know. and im running with no blocks in the rear with lowering keys. (Mind you, this makes the front sit about an inch or so lower than stock keys with no turns on bolts. So i have the jouncers cut to about 1/8-1/4 space before they touch. Problem im having is when i hit a bump in the road the suspension feels as if it bottoms on. like chatter your teeth hard ! I unbolted the shock at the bottom yesterday and pushed it up to see how much travel is there. ( have pics waiting for my friend to send them) It looks like i have about an 1 1/2 inches of travel up for the shock. I bounced the truck up and down while this was unbolted and the eyelet on the shock never came down far enough to match the eyelet on the bracket (thus telling me it wasnt moving enough to bottom out) Now i guess my question is. Does the suspension really travel more than that? And should i put the Z71 jouncers in and trim them less so that the suspension is sitting on them? Or will that cause a harsh ride?. Do i need a different shock? Is the Rancho RS999288 too long? Its the same shock i was using when the suspension was stock.
your bottomed out in that pic. you are offically "too low".
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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can you video it with the camera showing us the LCA bumpstop and shock and lower crossmember all at once (like your first pic shows). the torsion bar adapter looks really close to the bumpstop bracket that bolts where the stock jouce stop use to bolt as well as close to the crossmember
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
457
2
18
it is close, in fact I was watching that as he bounced the frame and the bracket actually pivots inward so to miss the jouncer bracket although on first glance it looks like it would just bump up and hit it. If I can get to my buddies shop with heat this evening I will get more video. Thanks for the help thus far
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
it is close, in fact I was watching that as he bounced the frame and the bracket actually pivots inward so to miss the jouncer bracket although on first glance it looks like it would just bump up and hit it. If I can get to my buddies shop with heat this evening I will get more video. Thanks for the help thus far
out of curiousity, what are you going over that you feel it bottom out on?
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
457
2
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Maybe I could take that bracket off and run an uncut Z71 jouncer? I took it out the other day and we have some road work going on there is a dip in the road where they are doing road work and when I first hit a bridge overpass .. To test I drove my company truck a 13 Silverado 1500 same speed to see just how bad of a bump it was , there's no doubt it's a hefty bump but the stock 1500 took it well. I don't mind a stiffer ride but the actual bottom out bang my truck does doesn't feel healthy!
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
17,812
255
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Phoenix Az
Maybe I could take that bracket off and run an uncut Z71 jouncer? I took it out the other day and we have some road work going on there is a dip in the road where they are doing road work and when I first hit a bridge overpass .. To test I drove my company truck a 13 Silverado 1500 same speed to see just how bad of a bump it was , there's no doubt it's a hefty bump but the stock 1500 took it well. I don't mind a stiffer ride but the actual bottom out bang my truck does doesn't feel healthy!
i have a feeling your blowing through the little bit of shock travel you have left. that 1.75" isnt much when you compare it to the size of the bump your describing.

put a zip tie around the shock shaft, go hit the bump (make the truck bottom out) and see where the zip tie is. if its smashed into the top or its gone, your issue is the shock being too long.

dont worry about the bumpstops yet.
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
457
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Im with you on that aspect, It just seems crazy itll travel that much more then i can move it on a bump ya know? But im no suspension guru
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Im with you on that aspect, It just seems crazy itll travel that much more then i can move it on a bump ya know? But im no suspension guru
you would be very surprised. if you have those ranchos turned down (closer to lvl 1), you have less valving inside to slow the upward movement of the wheel (compression). if you have the suspension travel, you can get a very smooth ride this way but when you dont, it causes a bottom out affect. turning your shocks up will slow the tire faster and possibly stock the bottoming out but at the cost of ride comfort.

for the mean time though, dont change the shock setting till you do the zip tie test. dont want to change too many things at once so we can figure out the issue
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
457
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Chevy, I assume youre talking about the shock eyelet for the zip tie not the body correct? Or youre talking about the stem? The plastic boot is on there pretty good I dont want to tear it off in case i cant use these and need to sell them cheap. I can see that ripping the adjuster off real quick too if youre referring to enough travel to go up the body
 

Chevy1925

don't know sh!t about IFS
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Oct 21, 2009
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you need to pull the shock boot down, put the zip tie around the shock shaft (the shiny shaft that goes into the body) and go test. i need to know if thats what bottoming out and this is teh simplest test that will tell us right away. otherwise its guessing
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
457
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I thought thats what you were saying, Thats going to take some ingenuity, Its a hard plastic boot not rubber. Ill have to see what the best route to remove that without destroying it is.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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wouldnt think its that hard of plastic if its moving up and down with the shock stroke. cant just pop it off the shock stem and push it down enough to get the zip tie on?
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
457
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I think its glued to the top part of the shock somehow, fully extended you cant reach up in there either. Its a hard plastic fake looking boot. Its pointless IMO, but surely you understand i dont want to butcher it all to hell if i have to get new shocks and try to sell these. Ill look this evening and see what kind of something i can come up with
 

TowU4Free

#SecretSquirrel
Aug 27, 2011
457
2
18
Its not mounted to the shock body... Its mounted to the top only , kinda like stock shocks if that helps
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
17,812
255
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Phoenix Az
i think its glued to the top part of the shock somehow, fully extended you cant reach up in there either. Its a hard plastic fake looking boot. Its pointless imo, but surely you understand i dont want to butcher it all to hell if i have to get new shocks and try to sell these. Ill look this evening and see what kind of something i can come up with
its not mounted to the shock body... Its mounted to the top only , kinda like stock shocks if that helps
10-4.
 

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