Lowered C20 Rough Ride

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thirstybob

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454
Hello!

Question,I hope someone can shed some light on this. I have a static lowered '74 C20 BBC. I used DJM lowered arms and Western Chassis hangers and shackles. The truck seems to ride OK but when I hit a deep manhole cover at around 40, the suspension seems to take it really hard. I hear a loud impact noise. Even small pot holes get the same reaction. What am I doing wrong? Or should I just get used to it having a modified vehicle? I've check for loose parts, low tire pressure, nothing bent or broken. It doesn't bottom out, just makes the noise. I haven't had it aligned yet.
,
What ever comments, good or bad are welcome.
 

Craig 85

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Typical of a lowered vehicle. Have you installed shorter bump stops? That my give you a little more suspension travel.
 

Dutch Rutter

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If you are running a low profile tire with large wheel that will also significantly effect your ride quality, and make it ride rough. On a 3/4 ton you should have 10 ply e rated tires which have very stiff sidewalls. A rough ride is per the norm on a unloaded 3/4 ton lowered, lifted or even stock so could just be the nature of the beast, but i personally dont have experience with lowered suspensions.
 

thirstybob

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Typical of a lowered vehicle. Have you installed shorter bump stops? That my give you a little more suspension travel.
Thanks for the input. Good idea though.
 

thirstybob

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If you are running a low profile tire with large wheel that will also significantly effect your ride quality, and make it ride rough. On a 3/4 ton you should have 10 ply e rated tires which have very stiff sidewalls. A rough ride is per the norm on a unloaded 3/4 ton lowered, lifted or even stock so could just be the nature of the beast, but i personally dont have experience with lowered suspensions.
No low profile tires. Thanks for your input.
 

Frankenchevy

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Do you have any witness marks where things are hitting? Also, did you wait to tighten all your suspension components until after the truck was fully on the ground, loaded under it’s own weight?
 

thirstybob

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Do you have any witness marks where things are hitting? Also, did you wait to tighten all your suspension components until after the truck was fully on the ground, loaded under it’s own weight?
I did wait to tighten everything under it's own weight. good call. I need to heck for witness marks. Thanks for the suggestion.
 

ali_c20

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My c20 isn't lowered and rides rough without load. The old rock hard tires are not helping to improve ride quality :)
 

Kim Burke

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I’ve lowered trucks professionally and driven one since my first in 76. These trucks will be choppier lowered but a clank or heavy knock is something bottoming out most likely.
Extended shackles (on the lowest hole) will often allow the spring to come in contact with the bed sill in a bump. The sill should be marked by now. THAT is a hella racket.
If low enough to hit the bump stops, the shocks may be bottoming out as well. A cheap experiment would be cutting the rear bump stops in half with a saws-all. Disconnect the bottom of the shocks temporarily and take for a ride.
The front is probably not the problem with aftermarket a-arms.
 

thirstybob

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C20 Custom Deluxe
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454
I’ve lowered trucks professionally and driven one since my first in 76. These trucks will be choppier lowered but a clank or heavy knock is something bottoming out most likely.
Extended shackles (on the lowest hole) will often allow the spring to come in contact with the bed sill in a bump. The sill should be marked by now. THAT is a hella racket.
If low enough to hit the bump stops, the shocks may be bottoming out as well. A cheap experiment would be cutting the rear bump stops in half with a saws-all. Disconnect the bottom of the shocks temporarily and take for a ride.
The front is probably not the problem with aftermarket a-arms.
Thanks for the reply and the suggestions. I'll give it a shot.
 

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