Trailing arm Angle for a 4-Link...

seth449

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I am using a CAD program to create parts for my four link project and my Excel file that contains my 4-link calculator is driving me crazy...... :eek:
So my question is, what angle is desirable in the desert for my trailing arm angle? I heard that 10 degrees is a good number but some set ups appear to be around 15-20 degrees.
Can anyone confirm this?
Thank you in advance,
 

partybarge_pilot

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Not the most important number. It will be dictated by other factors. Don't sweat it, concentrate more on squat #'s and plunge.
 

seth449

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Not the most important number. It will be dictated by other factors. Don't sweat it, concentrate more on squat #'s and plunge.
Thanks partybarge_pilot! I was going to use the trailing arm angle to decide my trailing arm length in conjunction with the upper links.
 

Chris_Wilson

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I concentrated on minimizing both roll steer and plunge and have been happy with the result. Others focus on other items but they are all related and everything is a compromise.
 

seth449

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I concentrated on minimizing both roll steer and plunge and have been happy with the result. Others focus on other items but they are all related and everything is a compromise.
Chris, I have never heard the term "Plunge" when dealing with a 4-Link. I have dealt with axle plunge and CV angles but what do you mean by "plunge" on a 4-link?
Thank you again,
 

partybarge_pilot

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everything is a compromise.

Truth!^^^^^

Your DS length will dictate your lower link length. Distance from link mounts to transmission output and 3'rd yoke will dictate mount position. Ground clearance at bump and uptravel at ride height will dictate link angle.

You can play with all of these a little to work on plunge/roll steer.
 

Chris_Wilson

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Chris, I have never heard the term "Plunge" when dealing with a 4-Link. I have dealt with axle plunge and CV angles but what do you mean by "plunge" on a 4-link?
Thank you again,

Drive shaft plunge is the enemy. It can kill transmissions due to stiction. Splines do not like to slide while under torque/heat. Same issue as plunging axles have on 1 cars.
 

seth449

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Truth!^^^^^

Your DS length will dictate your lower link length. Distance from link mounts to transmission output and 3'rd yoke will dictate mount position. Ground clearance at bump and uptravel at ride height will dictate link angle.

You can play with all of these a little to work on plunge/roll steer.
Traditionally the trailing arm is mounted under the frame but I found a chevy Blazer with the trailing arms mounted on the sides of the frame. I might consider going this route as it will be easier to change angles at a later time.
Thanks guys for quick replies!
 

Chris_Wilson

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All 4-link drive shafts run a slip joint. Sometimes it's in the tail housing.
 
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