4 link full droop driveshaft hitting frame

[65 Cobra Dude]

I am building a Hot Rod for a customer with the 4 link suspension. The longer shocks are in the rear per the instructions and I have the suspension points on the lower holes. I cannot connect the driveshaft without lifting the rear end while at full droop because it hits the frame at the driveshaft safety loop on a Gen II Hot Rod. There are no limit straps. Anyone else run into this issue and if so, how did you fix it? I have a set of Roadster limit straps that I was thinking of making a bracket and using them.

Thx,

Henry

[CDXXVII]

Do you have your pinion angle set yet?

Pictures?

[65 Cobra Dude]

I guess I am not sure how to set pinion angle on a 4 link? The upper and lower control arms are fixed length. If I am
Missing something, please let me know?

Thx,

Henry

[CDXXVII]

Adjustable Uppers but only if needed.

https://www.spohn.net/shop/Factory-Five-Racing-MK3-MK4-Roadster/Adjustable-Rear-Upper-Control-Arms-with-Del-Sphere-Pivot-Joints.html


I guess I am not sure how to set pinion angle on a 4 link? The upper and lower control arms are fixed length. If I am
Missing something, please let me know?

Thx,

Henry

[65 Cobra Dude]

Thanks for the link. I know there’s not a lot of 4 links out there but I’m guessing others have run into this issue as well and maybe there is another solution other than buying new uppers. Anyone use limit straps?
Thx,

Henry

[Arrowhead]

Are all the control arm bolts tight? When you torque all the bolts, it will take the slack out of the 4 link and uppers will straighten out and roll the axle back so the pinion will turn up. Other than that, yea, there's no adjustment on the 4 link other than the lower mounts on the axle.

[DS9941]

Do you have the correct transmission mount and spacing. I had to space my trans mount up a little to get everything to work

[65 Cobra Dude]

DS,

I am using the stock FFR tranny mount. Are you saying your driveshaft does not hit the frame at full droop? Looks like the tranny would need quite the shim. Everything is tight and I ended up using pickup truck tail gate straps as knit straps for now.

Thx,

Henry

[myjones]

Henry
I used tailgate cables for limits on my 4 link. I ran them from the torque boxes to the chassis tubes so they were as far outboard
as possible. If they were closer to the middle and only one side was at full droop it would allow the other tire to contact the fender.
HTH
Dale

[FFinisher]

nevermind

[qrtrpounder]

Henry,

How did you end up fixing your driveshaft contact? I have the exact same issue - was also thinking about making some straps.

[sread]

My gen 1 is going to need limit straps also - I think it is pretty common

[65 Cobra Dude]

Guys,

I ended up setting the ride height first and then shimmed the tranny rear about 1/2 inch up. I have about 1/4” space now between DS and frame.

Henry

[NAZ]

Henry, does that mean you have 1/4" clearance at ride height or at full droop? And pinion angle?

[TDSapp]

65 Cobra Dude,

If I was you, I would try and talk your customer into buying the adjustable 4 link control arms. Not only will it help you adjust the pinion angle, it will allow you to move the rear end back from the frame. When you use the fixed length control arms your rear end will not be centered in the wheel well, which will also limit your tire\wheel selections.

Many good reasons to go to adjustable ones, no reasons not to go to them.


Tim

[Higgi56]

i am running into the same issue .

first i put the shocks in the upper bolt holes to raise the rear end.
second i backed off on the adjustment of the springs.

i am waiting for the engine and tranny to go in, but my next steps were to raise the upper and lower control arms to the top set of holes in the brackets.

i contacted FFR and they said to set the pinion angle after the weight is one the frame.

my guess is the shocks will need go be shortened and/or adjustable control arms used.

i would recommend to contact ffr

i hope with enough feedback about the same issue they'll provide a proper solution.

[peterh226]

I have the same issue with the 3-link. Driveshaft will hit the floor at full droop. I dont see any issue when on the ground, but if you jack it up to change a tire, then the driveshaft would get damaged. I like the tailgate straps idea. Like to see some examples of what people have done.

[65 Cobra Dude]

FFR sent us some adjustable upper control arms to fix this issue. I have yet to install them because the car is at paint and will be back in 2 weeks or so. I’ll let you know how it works out.

Thx,

Henry

[NAZ]

There are better ways to limit travel but use of nylon straps (look like seat belt material) is common in off-road race vehicles. Pro Comp make some quality ones and you can get them from Summit Racing.

[peterh226]

There are better ways to limit travel but use of nylon straps (look like seat belt material) is common in off-road race vehicles. Pro Comp make some quality ones and you can get them from Summit Racing.

Excellent. I think I can mount to holes in front of the shock that will even look good. Great suggestion, Thanks!

[sethmark]

Just mount the shock in the top hole. Eliminates the issue of the ds hitting full droop.