lower control arm bump stops

[David Dickerson]

I have my '74 Duster sitting at the desired ride height and have noticed the bump stops on the lower control arms are touching the bottom of the frame. The adjustments for the torsion bars are at about half travel. I also have QA1 upper control arms. I could raise the front, but would rather not. Looked at a few other dusters at shows and noticed most had about 1/2-1" travel. One had the bump stops removed. Don't think that would be a good idea. What about shaving off some material? Car handles well, but not sure if this condition is ok.

 

[TrailBeast]

I have my '74 Duster sitting at the desired ride height and have noticed the bump stops on the lower control arms are touching the bottom of the frame. The adjustments for the torsion bars are at about half travel. I also have QA1 upper control arms. I could raise the front, but would rather not. Looked at a few other dusters at shows and noticed most had about 1/2-1" travel. One had the bump stops removed. Don't think that would be a good idea. What about shaving off some material? Car handles well, but not sure if this condition is ok.

Some do shave them for that exact reason.
They get pretty harsh when they hit the end of the travel with them removed.

 

[David Dickerson]

Is it bad to have them touching? How much space should there be? What should I notice in handling conditions. Could it cause any front end issues?

 

[Murray]

The purpose of that rubber bump stop is to minimize or soften the impact of metal to metal bottoming out. If you must run at that ride height, then cut down that bumper, but I would try to keep some of it.

 

[David Dickerson]

The purpose of that rubber bump stop is to minimize or soften the impact of metal to metal bottoming out. If you must run at that ride height, then cut down that bumper, but I would try to keep some of it.

Will Changing the ride height affect alignment? Still wondering what affects the bump stop has if it is touching?

 

[MOPAROFFICIAL]

Will Changing the ride height affect alignment? Still wondering what affects the bump stop has if it is touching?

Yes, and the effect of the bump stop touching is... The torsion bar is not allowed to travel aka 'do its job' and you're riding around on rubber, not suspension

 

[Murray]

Ride height effects alignment. If you seriously change the height then you should check the alignment. If you drive the car with bump stop touching, I would expect to hear a rubbing noise. In additionally there is now no travel left in the suspension so you will feel every bump in road.

 

[72bluNblu]

If you have stock sized torsion bars, you need to raise your car back up to the stock ride height.

If you have torsion bars larger than 1”, you can swap out the lower bump stop. I use these Energy Suspension Bump Stops 9.9132G

Keep in mind though that you’re changing the function of the bump stop when you change to a small poly stop. You’ll need to have enough suspension travel and wheel rate so that you’re not hitting the bump stop all the time.

The factory bump stops are soft and progressive, they were designed to be used as part of the suspension to add some additional resistance to the suspension travel to work with the really soft stock torsion bars. They were designed to be used, and often with the stock suspension, even at the stock ride height, the bump stops will be contacted frequently. I have talked to people on this board that had their cars riding on the factory bump stops without even knowing it.

If you change to short poly bump stops, you don’t want to hit them all the time. They will help protect the hard parts, but they will disturb the handling of the car when you hit them. So if you only have an inch of travel between the bump stop and the frame, you need to have a torsion bar stiff enough to not hit the bump stops all the time. For about 1” of travel to a poly bump stop, that torsion bar will need to be 1.06 to 1.12”. If your bars are smaller than that, you need more space if you go poly.

 

[72Dart6pack]

Slam it to the ground. The in the weeds look rocks. Who needs bump stops? As long as the car looks bitc* n.

 

[el5dart]

you could raise it to stock height and but 2 inch drop spindles

 

[72bluNblu]

you could raise it to stock height and but 2 inch drop spindles

Drop spindles on the torsion bar suspension are a waste of time and money

They cost twice as much as a set of larger torsion bars that will also allow you to lower the car (less suspension travel needed with the higher wheel rate). Using the torsion bar adjusters to lower the car, a larger set of torsion bars and shorter bump stops to compensate for the loss of suspension travel you will improve the suspension geometry and handling of the car. You get better camber gain curves, less bump steer, and a better roll center than you do with the factory geometry.

With drop spindles you keep the factory geometry that was intended for bias ply's. That's assuming you lower the car the full 2"- if you use 2" drop spindles and set the ride height so the car isn't the full 2" lower you actually get even worse geometry than factory.