Lower Control Arm bushings

[inviolet]

Whats up guys,

 I was wondering why does Mopar Muscle magazine recommend the stock bushing over the polyurethane bushing for the lower control arms? Their argument apparently is that the stock bushing holds the lower pivoting shaft better than the urethane bushing?

Mopar Muscle magazine writes "We favor stock rubber pieces in the lower control arms because the poly bushings have no means of positively retaining the control arm to the pivot shaft"

I can't see this being an issue.  You have the torsion bar that holds everything in place and when you use the polyurethane bushing you are suppose to use a different pivoting shaft that is thicker. This should keep the lower control arm secure?

Can the polyurethane bushing effect vertical suspension travel? Or could cause unwanted horizontal travel if it is not positively locked to the pivoting shaft?

Anyone have any opinions on this?

Mopar Muscle magazine link:

http://www.moparmusclemagazine.com/tipstricks/155_0306_control_arms/photo_14.html


Lower arms with polyurethane bushing and larger pivoting shaft:

[Kapteenikosmos]

I've read the same thing couple of times and decided to go with plain rubber. I actually use all rubber in front and poly only on the rear springs. I think that if the pivot shaft is bit floppy because of the poly bushings it might make some clunking sounds while braking in forward direction and after that in reverse direction.

Btw, you seem to have the sway bar brackets on the lower arms. That is, if the pic is from your control arm? I'm making a set from from sheet metal to mine and I'm still bit wondering the orientation of the bracket.

Can you take a sideview photo from them so that it shows the orientation of the upper mating surface on the sway bar bracket. It's seems that it isn't parallel with the upper edge of the control arm, which is what I saw on some homemade swaybar bracket version. It seems to be tilting bit to the pivoting arm. Can you take a pic from the other side so that it would show if it is tilting and also how much is it coming over the upper edge of the control arm.

[inviolet]

Sorry, the control arms are already in the car. I will see if I have any other pictures I can post.

[Chryco Psycho]

where can the arm go ?
 it has the T bar in the rear & the pin into the K in front

[inviolet]

That's what I say. But under sudden breaking I do hear a strange sound coming from the suspension. It also happens if I release the clutch abruptly. I've gone over every blot in the front end and everything looks tight. 

Is the arms suppose to pivot around the shaft at the bushing or at the shaft in the k frame? I think its suppose to pivot at the k frame.

[Moparal]

The control arms  move but the bushings should not move what so ever. Torq bar in rear holds the arms and the nut through the k member. The hole arm itself moves . The 3/4 inch bolt adjust the torq pressure that limits the movement by weight. The bushing is press fitted on both inner and outer shells. So it stays in place.  Did I say that right? I think I did.  The bushing will not move

[JaxHemi]

Stock rubber bushings seem less affected by ozone deterioration than poly.

Jack

[farmboy70]

I've read the same thing couple of times and decided to go with plain rubber. I actually use all rubber in front and poly only on the rear springs. I think that if the pivot shaft is bit floppy because of the poly bushings it might make some clunking sounds while braking in forward direction and after that in reverse direction.

Btw, you seem to have the sway bar brackets on the lower arms. That is, if the pic is from your control arm? I'm making a set from from sheet metal to mine and I'm still bit wondering the orientation of the bracket.

Can you take a sideview photo from them so that it shows the orientation of the upper mating surface on the sway bar bracket. It's seems that it isn't parallel with the upper edge of the control arm, which is what I saw on some homemade swaybar bracket version. It seems to be tilting bit to the pivoting arm. Can you take a pic from the other side so that it would show if it is tilting and also how much is it coming over the upper edge of the control arm.

Here is a diagram I saved some time ago that may help.
Dave

[LAA66]

 The strut really holds the control arm in place using polyurethane, that and (somewhat) the torsion bar. Any slop in the t-bar length though can allow the arm to move. With poly, the arm (bolted to the K member) can actually be slid back and removed without the strut and t-bar.

 Next time I  plan to use the factory bushings. Road noise and vibrations are more noticeable with poly IMO.

[Kapteenikosmos]

Here is a diagram I saved some time ago that may help
Dave

Excellent pic, huge thanks! 

Ville

[Chryco Psycho]

well I have seen 2 year old rubber bushings with cracks in the rubber

[autoxcuda]

The strut really holds the control arm in place using polyurethane, that and (somewhat) the torsion bar. Any slop in the t-bar length though can allow the arm to move. With poly, the arm (bolted to the K member) can actually be slid back and removed without the strut and t-bar.

I agree the strut rod holds the wheel from for and aft movement.

The problems I had with the poly LCA bushings was gettting them to fit in the old shell. They would not press in without me shaving the OD of the poly and grinding clearance inside the ID of the old LCA bushing shell.

I polished the OD of the pin/shell and the ID of the old outer bushing shell. I think the polishing and the fitting kept me from getting squeeks



** Note the A-body pin in the middle with the round section can not be used with poly bushings.