Polyurethane Bushings?

[JMLaux]

Instead of creating ANOTHER new post about polyurethane bushings, I might as well just add to this thread:

Is there any information out there on the shore hardness of the various poly bushings the vendors supply? I've done a lot of research on poly bushing in general and it seems like most auto clubs/forms tend to geek out over the technical specs of aftermarket bushings but the only info I have been able to find on the DMC forums is they are stiffer than stock rubber.

[Morpheus]

Lots of great info in this thread! I am about to embark on a full poly upgrade for my front suspension and this will come in very handy. One question though:

Is it ok to use my stock LCAs (blasted and powder coated) with new lower ball joints, poly bushings, and Ed's brackets? I know the originals had their weaknesses, but with the improved strength of the LCA brackets they should last a lot longer, no?

[Patrick C]

Lots of great info in this thread! I am about to embark on a full poly upgrade for my front suspension and this will come in very handy. One question though:

Is it ok to use my stock LCAs (blasted and powder coated) with new lower ball joints, poly bushings, and Ed's brackets? I know the originals had their weaknesses, but with the improved strength of the LCA brackets they should last a lot longer, no?

The stock LCAs will still be weak, and now you are adding new stresses to them with stiffer bushings and braces. Many LCAs fail near the ball joint area, which the LCA braces will do nothing for. I strongly suggest updating them before you have a failure.

EDIT: Example photo attached.

[Mark D]

Lots of great info in this thread! I am about to embark on a full poly upgrade for my front suspension and this will come in very handy. One question though:

Is it ok to use my stock LCAs (blasted and powder coated) with new lower ball joints, poly bushings, and Ed's brackets? I know the originals had their weaknesses, but with the improved strength of the LCA brackets they should last a lot longer, no?

This is exactly what I did on my car and so far I've had no issues. I payed really close attention to the condition of the lower control arms as I was stripping and blasting them. Once they were in the raw I didn't see any evidence of severe pitting from rust or cracking so I powder coated them and installed new DMC Club UK ball joints. If you see any obvious signs of damage or if the corrosion has started causing the sheet metal to get pitted out you may want to replace them instead.

I also stripped and blasted the LCA support brackets. There was a lot of slag on the welds that was causing the paint to chip and peel off before I even had a chance to install them. Blasted them smooth and rounded off the hard edges slightly so that the powder coating would have a more rounded surface to adhere to. Sharp corners and edges tend to cause powder to thin out so if you radius anything sharp it will help with adhesion in the long run.

I think the new LCA braces that Ed is offering are stainless so you may not even need to worry about paint on those unless you are planning on painting the stainless black.

[MikeWard]

Lots of great info in this thread! I am about to embark on a full poly upgrade for my front suspension and this will come in very handy. One question though:

Is it ok to use my stock LCAs (blasted and powder coated) with new lower ball joints, poly bushings, and Ed's brackets? I know the originals had their weaknesses, but with the improved strength of the LCA brackets they should last a lot longer, no?

This is exactly what I did on my car and so far I've had no issues. I payed really close attention to the condition of the lower control arms as I was stripping and blasting them. Once they were in the raw I didn't see any evidence of severe pitting from rust or cracking so I powder coated them and installed new DMC Club UK ball joints. If you see any obvious signs of damage or if the corrosion has started causing the sheet metal to get pitted out you may want to replace them instead.

If you are going to go to the trouble of stripping the LCAs then it is a good idea / ideal time to weld in some strengthening plates before getting them powder coated, and rebuilding them with new balljoints and bushes.

lcas plated.jpg

[Morpheus]

If you are going to go to the trouble of stripping the LCAs then it is a good idea / ideal time to weld in some strengthening plates before getting them powder coated, and rebuilding them with new balljoints and bushes.

lcas plated.jpg

Does boxing in the OEM LCAs really help? I keep hearing that the weak spot is where the ball joint is pressed in. The LCA brackets help to provide strength and reduce the flexing of the rest of the arm, right?

[Morpheus]

This is exactly what I did on my car and so far I've had no issues. I payed really close attention to the condition of the lower control arms as I was stripping and blasting them. Once they were in the raw I didn't see any evidence of severe pitting from rust or cracking so I powder coated them and installed new DMC Club UK ball joints. If you see any obvious signs of damage or if the corrosion has started causing the sheet metal to get pitted out you may want to replace them instead.

I also stripped and blasted the LCA support brackets. There was a lot of slag on the welds that was causing the paint to chip and peel off before I even had a chance to install them. Blasted them smooth and rounded off the hard edges slightly so that the powder coating would have a more rounded surface to adhere to. Sharp corners and edges tend to cause powder to thin out so if you radius anything sharp it will help with adhesion in the long run.

I think the new LCA braces that Ed is offering are stainless so you may not even need to worry about paint on those unless you are planning on painting the stainless black.

Thanks for the reply, I intend to examine the arms after they are blasted to see if they are up to snuff. Mine only have 11K miles on them, so I'm hoping for the best.

[Mark D]

Does boxing in the OEM LCAs really help? I keep hearing that the weak spot is where the ball joint is pressed in. The LCA brackets help to provide strength and reduce the flexing of the rest of the arm, right?

I went back and forth when I was trying to decide if I should to box the LCA's or not... I ultimately I decided not to, but I may have been just being overly cautious.

The reasons were:

-I didn't want to strengthen the arm unevenly and relocate stress to the areas where the boxing plates didn't have good coverage. I was concerned about getting more stress near where the ball joint is pressed in, which is where the arms typically like to fail. The plates that MikeWard posted look pretty nice though and look like they go all the way up the end of the flange to get pretty good coverage. It's still somewhat of an unknown as to how much the boxing actually helps. And there is no one standard design for the bottom plates that people use so in my mind it was sort of an untested solution.

-I was also concerned about being able to fully paint inside the arm once it was boxed to prevent future corrosion issues.

-I'm not an expert welder myself so I'd have to trust someone else to not to screw up welding on parts that were no longer available at the time. I was thinking about the possibility of getting excessive heat into the arm and residual stress issues/ distortion of the parts.

I finally just decided that I'd leave the stock arms alone and that adding the bolt on side reinforcements would reduce the forces on the arms and that would be enough for me. If I were doing it today and had the money I'd probably buy a set DPI's stainless arms or DMCMW's aluminum arms. When I did my car neither of those options were available yet.

I'd be interested to know if anyone has ever failed a boxed in control arm, or if anyone has ever failed a stock arm while using Ed's reinforcement plates. I haven't heard of any failures of either setup.

[MikeWard]

Does boxing in the OEM LCAs really help? I keep hearing that the weak spot is where the ball joint is pressed in. The LCA brackets help to provide strength and reduce the flexing of the rest of the arm, right?

With how much flex those arms are under in use, the boxing can only help in my opinion.

Re the area where the ball joint is pressed in, it's good practice to add a ball joint reinforcing collar.

These LCAs had the boxing, PJ Grady ball joint reinforcing collars, new ball joints and bushes, and Eds support brackets. Belt and braces.
IMG_2073.jpg

That's about the best you can do before you step up to upgraded LCAs such as DMCMWs ally arms, or DPI Stainless arms. Although those are significantly more expensive than refurbing your own arms as above. Depends on how much budget you have to play with (I'm running DMCMWs ally arms on my car)

[MikeWard]

The plates that MikeWard posted look pretty nice though and look like they go all the way up the end of the flange to get pretty good coverage. It's still somewhat of an unknown as to how much the boxing actually helps. And there is no one standard design for the bottom plates that people use so in my mind it was sort of an untested solution.

That design has been finessed a little more since those arms were refurbished. The new plate design is now a single piece rather than two separate pieces.
LCA plate.jpg