[Caddyshack95]

Having gone to poly lowers on the 91, I can say, it's subtly different for different road conditions than rubber. For slow moving up down dips, they actually feel softer as there is no bushing twist to add 'spring rate'. Other conditions like pot holes where the tire is also jarred rearward during the impact, they feel more harsh. So really depends on what you roads are like where you live. Same setup maybe be horrible one place and perfect somewhere else.

That's where I am stuck. If I want to add a stiffer sway bar, I'm going to have to upgrade the LCA.... But the new ones all come with poly bushings.

I have a tow pack so my front bar is already 30mm and rear bar is 26mm straight from the factory.


The rubber bushings are no doubt TOAST. So how soft will they really be right now? Will I even notice a difference between new poly and old rubber? Roads here aren't glass like FL or AZ, so we do have potholes. However, I go back to age of bushings and what the difference will be real world.


Any ideas on that front?

 

[91ss]

I've ran with stock arms and the 1.5" HA bar most of the 91's life. Close to 200k just as a reference. It's all how you treat, or abuse the car...

 

[Caddylack]

That's where I am stuck. If I want to add a stiffer sway bar, I'm going to have to upgrade the LCA.... But the new ones all come with poly bushings.

I have a tow pack so my front bar is already 30mm and rear bar is 26mm straight from the factory.


The rubber bushings are no doubt TOAST. So how soft will they really be right now? Will I even notice a difference between new poly and old rubber? Roads here aren't glass like FL or AZ, so we do have potholes. However, I go back to age of bushings and what the difference will be real world.


Any ideas on that front?

I've ran with stock arms and the 1.5" HA bar most of the 91's life. Close to 200k just as a reference. It's all how you treat, or abuse the car...

It is NOT necessary to upgrade your LCA's just because you upgraded your sway bar. Like 91ss said, it's all about how you drive the car.

If you are going to be tracking the car, you need to upgrade the LCA's, as they are one of the known weak points in our suspension. For a daily driver, I would not hesitate to use a set of new OEM arms. You will be fine.

 

[Caddyshack95]

I've ran with stock arms and the 1.5" HA bar most of the 91's life. Close to 200k just as a reference. It's all how you treat, or abuse the car...

It is NOT necessary to upgrade your LCA's just because you upgraded your sway bar. Like 91ss said, it's all about how you drive the car.

If you are going to be tracking the car, you need to upgrade the LCA's, as they are one of the known weak points in our suspension. For a daily driver, I would not hesitate to use a set of new OEM arms. You will be fine.

I see on both fronts here guys. So tracking it will almost certainly cause the system to fail with a new sway bar.... No track and massive stress, the new sway bar will be fine with OEM LCA (new).

So back to a point: New (OEM) LCA will certainly improve the ride quality as they are newer and new bushings. Is it worth the sway bar upgrade? As @Caddylack and I have been discussing via PM, my car already has thicker sway bars from the factory.

ADD: @Caddylack where do you even get a new OEM LCA? I can't find anything on RockAuto or Autozone....

 

[Caddylack]

I see on both fronts here guys. So tracking it will almost certainly cause the system to fail with a new sway bar.... No track and massive stress, the new sway bar will be fine with OEM LCA (new).

So back to a point: New (OEM) LCA will certainly improve the ride quality as they are newer and new bushings. Is it worth the sway bar upgrade? As @Caddylack and I have been discussing via PM, my car already has thicker sway bars from the factory.

ADD: @Caddylack where do you even get a new OEM LCA? I can't find anything on RockAuto or Autozone....

Definitely verify the size of the sway bars on your car, just because there has been conflicting info posted here on the forum. Harbor Freight sells a little dial caliper for like 2-3 dollars or something, and you can use that to find out the exact size.

There may not be an OEM equivalent lower out there. I will have to check. I had a really tough time finding OEM rear uppers, and ultimately went with a Dorman part number that was listed for like 77-81 Caprice or something weird like that. You will be surprised what you find on Rock Auto if you spend enough time browsing.

The bushings are the same for the uppers and lowers, and those are readily available. I would say go ahead and order the new bushings and then have Brent press them in. He might be able to box them for you, I'm not sure.

You could always just order the aftermarket lowers with the poly bushings. It won't kill you to have a couple of poly bushings, but just think of it as a spectrum. The more rubber bushings that you replace with poly, the more firm the ride will be.

Keep in mind you also have bushings on your axle housing where the uppers attach, and those are more of a pain just because the axle is obviously attached to the car.

 

[Caddylack]

This just in:

Dorman 520571 is available on Rock Auto for $36

At that price, don't even bother with getting bushings pressed.

 

[Caddylack]

Dorman 520572 are the uppers, and they cost $20

 

[95wagon]

Think you will find the housing bushes are different.
Pre metric, they all were the same but when the other 6 got largers with 14mm hardware, the diff upper didn't

 

[Caddylack]

Think you will find the housing bushes are different.
Pre metric, they all were the same but when the other 6 got largers with 14mm hardware, the diff upper didn't

So, what you're saying is that the (older) uppers will not bolt to the 94-96 axle housing bushings properly? Swapping the bushings would solve this problem?

If those Dorman uppers don't work, then that would also be news to Brent.

The lowers should be a non-issue, as they are listed for 1992 Roadmaster.

 

[95wagon]

you might have misinterpereted my post.
At one point in this susps life span all 8 bushings were interchangeble.
When they became metric in later years, the housing mounted bushing did not change.
Then 6 bushes were the same , two were not.
Look at the hardware on our cars.
The bolts in the housing bushings are smaller dia than the rest.
Can't tell you the exact year change.
All 91-96 though, 14mm in 6 postions ,smaller dia in top housing.

 

[Caddyshack95]

So, what you're saying is that the (older) uppers will not bolt to the 94-96 axle housing bushings properly? Swapping the bushings would solve this problem?

If those Dorman uppers don't work, then that would also be news to Brent.

The lowers should be a non-issue, as they are listed for 1992 Roadmaster.

you might have misinterpereted my post.
At one point in this susps life span all 8 bushings were interchangeble.
When they became metric in later years, the housing mounted bushing did not change.
Then 6 bushes were the same , two were not.
Look at the hardware on our cars.
The bolts in the housing bushings are smaller dia than the rest.
Can't tell you the exact year change.
All 91-96 though, 14mm in 6 postions ,smaller dia in top housing.

Thanks for the good post. Incredible find on the OEM (sorta) LCA.

So are we saying that the LCA would fit right in to my car if I decide to go that route?


I need to verify my sway bar size, which I can hopefully do soon. Yes the poly spectrum makes complete sense. That and stiffening the frame a bit as well. I would like to look at how bad the LCA bushings are... That will also sway my decision (LOL).

 

[Caddylack]

you might have misinterpereted my post.
At one point in this susps life span all 8 bushings were interchangeble.
When they became metric in later years, the housing mounted bushing did not change.
Then 6 bushes were the same , two were not.
Look at the hardware on our cars.
The bolts in the housing bushings are smaller dia than the rest.
Can't tell you the exact year change.
All 91-96 though, 14mm in 6 postions ,smaller dia in top housing.

Haha... This just happened the other day!

I knew exactly what you meant, and we are on the same page.

Thanks for the good post. Incredible find on the OEM (sorta) LCA.

So are we saying that the LCA would fit right in to my car if I decide to go that route?


I need to verify my sway bar size, which I can hopefully do soon. Yes the poly spectrum makes complete sense. That and stiffening the frame a bit as well. I would like to look at how bad the LCA bushings are... That will also sway my decision (LOL).

That lower control arm is a direct bolt-in for your car.

The upper is almost a direct bolt-in, but will require some sort of adjustment (like changing the bushings on your axle housing).

 

[Caddyshack95]

Haha... This just happened the other day!

I knew exactly what you meant, and we are on the same page.


That lower control arm is a direct bolt-in for your car.

The upper is almost a direct bolt-in, but will require some sort of adjustment (like changing the bushings on your axle housing).

Thank you for posting.


I just wanted to drop by and say that I verified the front sway bar diameter on my car is 30mm... V4P Tow pack car, to keep things updated.

I was too tuckered out to verify the rear after working on the front suspension.

 

[Caddylack]

you might have misinterpereted my post.
At one point in this susps life span all 8 bushings were interchangeble.
When they became metric in later years, the housing mounted bushing did not change.
Then 6 bushes were the same , two were not.
Look at the hardware on our cars.
The bolts in the housing bushings are smaller dia than the rest.
Can't tell you the exact year change.
All 91-96 though, 14mm in 6 postions ,smaller dia in top housing.

Wait... I just realized I had it backwards.

If the housing bushing didn't change, then that means we know the older uppers will use the correct size bolt on that end.

It's the other 6 bushings that we need to be skeptical of, given we don't know the exact year they changed.

Is that correct?

 

[Caddyshack95]

resurrecting from the dead. My inserts and bolts that hold the sway bar into the LCA are completely toast. Bolts broke and the insert is messed up.

So I’m back to the drawing board. It looks like Dorman 520571 doesn’t have the insert to hold the sway bar in place. I think I’m not going to be able to make that work.

I’ve come across BMR and UMI LCAs at the same price… fully boxed, both poly bushings with grease fittings.

For what it’s worth, BMR discusses “internally fluted bushings”

see quote:BMR’s bushings are internally fluted, which allows grease to evenly coat the inner sleeve and keep the grease in the bushing under high loads. These flutes also direct grease to the outer edge of the bushing, keeping the thrust surface lubricated. This efficient lubrication ensures quiet, reliable operation over the life of the bushings.

Is there One I should favor over the other? Would like to get these ordered and installed very soon.
Thanks a million!

 

[Marky Dissod]

If it turns out that it's easier to order BMR or UMI lower trailing arms, than to order 9C1 lower trailing arms, I get why you might wind up with BMR or UMI lower trailing arms.

 

[Caddylack]

I've never been fluted. Not even once.

 

[Caddyshack95]

If it turns out that it's easier to order BMR or UMI lower trailing arms, than to order 9C1 lower trailing arms, I get why you might wind up with BMR or UMI lower trailing arms.

Right.... I have looked around and it doesn't seem to be possible to get the 9C1 arms.


Any ideas on the BMR vs UMI?


BMR's fluting sounds interesting...

 

[1slow96]

Sounds more like "marketing" to me....

 

[Marky Dissod]

Would not be surprised if the UMI's bushings-&-lube arrangement was basically identical.