4-bar help Request

[SCOTI]

I’m piecing together a parallel 4-bar system for my square body C30. It’s an early version of Ride Tech’s HD ‘bolt-on’ axle brackets & links/bars.

The early kit I have utilizes 4 equal length links w/poly bushings on one end & rod ends on the other. The front hanger/bracket for the links/bars replaces the original front leaf spring hanger.
I’m more familiar w/Ride Tech’s revised version of this system. It utilizes un-equal length links (shorter uppers) w/poly bushings on both ends. The revised set-up also re-uses the front OE leaf hanger as the lower mounting point & locates the upper links w/a different bracket.

Since this kit is ‘gently used’, I’ll need to re-build the front mount/bracket. The info I seek is which is the better choice when building a parallel 4-bar? Should I base the set-up on equal length upper & lower bars that are not true parallel (from side view) or un-equal length bars that are parallel? This would help me decide whether I should utilize the OE lower mounting point & just build a new upper mount; or something else.

The dimension between the upper & lower axle brackets is 8” (4” OD axle tube + 2” @ top bracket & 2” @ bottom bracket). The links/bars are about 25” in length. The un-equal length bars would be much easier to package....

[SCOTI]

Additional relevant info.... Estimating 8" rear drop @ ride height.

[aggie91]

Scoti, wish I could be helpful here, but out of my experience.

I am going to follow along since I am working on trying to get a dually myself since we last talked. I was thinking of using Ridetech's new HD universal 4 link.

If someone had pictures of the early version, that would really help.

[SCOTI]

Originally Posted by aggie91

Scoti, wish I could be helpful here, but out of my experience.

I am going to follow along since I am working on trying to get a dually myself since we last talked. I was thinking of using Ridetech's new HD universal 4 link.

If someone had pictures of the early version, that would really help.

I knew the Ride Tech bolt-on 73-87 HD Airbar kit wouldnt be @ my desired ride height (they spec no c-section is required for the kit) so some adjustments were expected regardless.

I picked this kit up for cheap (vs a new kit) knowing there would be tweaks (required? desired?? ). I can't afford $1500-2K for rear suspension set-ups when I have multiple trucks. I have to work within my means or I would buy new (PB or Ride Techs newest pkg).

[wraprail]

I suppose you are going to need to piece it together and see what happens to your pinion angle through your suspension travel. With unequal length arms their position compared to each other will determine that, along with other factors.
You could shorten the uppers and do a triangulated 4 link. Trial and error unless someone has instructions or installed dimensions of the original kit.
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[SCOTI]

Originally Posted by wraprail

I suppose you are going to need to piece it together and see what happens to your pinion angle through your suspension travel. With unequal length arms their position compared to each other will determine that, along with other factors.
You could shorten the uppers and do a triangulated 4 link. Trial and error unless someone has instructions or installed dimensions of the original kit.
Posted via Mobile Device

Doing a parallel only. Prob with...

I suppose you are going to need to piece it together and see what happens to your pinion angle through your suspension travel. With unequal length arms their position compared to each

...is, I would prefer not to remove 20 rivets unless I really need to (one choice is inherently better vs the other). Either orientation will likely provide minimal pinion shift w/my limited 4" of normal travel (I drive my stuff low all the time; don't lay out; etc...).

[SCOTI]

Originally Posted by wraprail

.... Trial and error unless someone has instructions or installed dimensions of the original kit.

Just noticed this statement specifically.... I have both (instructions & dimensions) for the kit.

What I don't know is, is one set-up (equal length but not parallel) better vs the other (un-equal length but parallel/revised kit). The kit Ride Tech manufactured was revised from the former to the latter. I can build it either way.