"Updated" Deville Control Arms

[BodybyFisher]

I replaced my control arm bushings a couple of months ago and they were tight, I was thinking that I was wasting my time, they looked very different than this control arm

[JIMDTS]

The bushing play a big part in the front suspension. On my 01 dts when I looked under the car when I had the ac issue. I noticed I had a broken bolt on the end of the sway bar it the bolt that goes through the bushing at the end of the sway bar. The sway bar was hanging down a few inches. I can’t believe I didn’t notice it from driving the car .The front end felt a little sloppy It must have not been broken too long I would have noticed it if I was driving the car hard I did notice a big difference after I replaced the bushing & bolt.

Jim

[Logan]

Well the weather has cooled off enough to play with the GXP arms.

Turns out the GXP arms use the same front bushings as the Deville. Search Google and the same wiggle problem is reported for Auroras, Bonnevilles, and Buicks.

Kevin, if you had one of these cars, you would understand the issue.

GM has released new lower arms, but those arms are reported to be flubbed. Those arms are #25746324 and #25746325. They too use a forward Hydro bushing.

Anyway, got the forward bushing out today on both arms. Not really designed to be replaced..Had to burn the bushings out, then hammer out a sleeve. Also they are a 'hydro' bushing, so fluid did blow out as it was burned out.

May get time Weds to drag a arm up to Napa and see if I can fit a more traditonal bushing. It may be for a Silverado..Chrysler..Honda...who knows.

Much easier to do this job with the $50 eBay pair of GXP arms off the car..

And now, I also have the J 38792 EVA tool..

[cwcolton]

Are you talking about the control arm that has the cruse control, wiper blads and turn signal. If so I can send you an item number from ebay. Its not my item, I just found the control arm a few days ago and I bought one. The price is better the $50.00.

I am not trying to sell you anything, i just happen to be looking for the same thing.

[JasonA]

It is interesting that the bushing appears to allow a lot of movement in the X-axis. By that, do you mean that, if installed on the car, you'd be able to "pull" and "push" on the front of the LCA, horizontally, inward and outward and you'd see movement? But if you tried to "lift" the front of the LCA, there'd be very little movement?

That would seem to allow for a lot of dynamic changes to alignment (specifically, toe).

[Logan]

It is interesting that the bushing appears to allow a lot of movement in the X-axis. By that, do you mean that, if installed on the car, you'd be able to "pull" and "push" on the front of the LCA, horizontally, inward and outward and you'd see movement? But if you tried to "lift" the front of the LCA, there'd be very little movement?

That would seem to allow for a lot of dynamic changes to alignment (specifically, toe).

Yes, exactly what I see.

You can go out to your car right now, there is a large enough gap at the front bushing, you can insert a screwdriver, any wiggle the arm side to side. But not up and down.

The forward bushing is a good foot away from the ball joint. Imagine a 50 lb wheel and tire assembly, spining at 14 times a second (70 mph). What effect would that have on the front bushing.

It also seems that during acceleration. There would be some toe issues too.

[JasonA]

This may be an obvious observation, but it appears that lateral runout (vs. radial runout) of the wheel/tire assembly is the key here. In my (un)educated understanding, a road-force balance helps a lot, but that addresses primarily radial runout, and more specifically, differences in radial force on the tire/wheel (due to differences in sidewall stiffness, height, etc). Given the way the suspension is setup (with two inline bushings), they probably had to locate that front bushing pretty far forward to reduce the amount of leverage the wheel/tire assembly has on it. Imagine the other extreme -- if it were located just a few inches forward of the rear bushing. The wheel would have too much leverage on it then...and we'd REALLY have a problem.

The previous design definitely handled this situation better. The control arm proper was simply a link between the wheel and the subframe. A strut rod was permanently fixed to the control arm which extended forward and used a body bushing-type bushing, with a vertical bolt. Any lateral force from the wheel was transmitted to this bushing, which used compressive forces to withstand the input. I'm not sure why the hydro bushing in the G-chassis suspension doesn't have the same resistance horizontally as it does vertically. I'm sure it's done for isolation, but perhaps taken to an unfortunate extreme.

Are there machines (a standard Hunter machine perhaps) available at tire shops that can measure a wheel's lateral runout? Or is that pretty specialized such that only a dealer would have access to it?

[Logan]

Napa had no interest in searching thru bushings.

Went to AutoZone. They let me go in the back to search for a bushing that would fit.

In 5 minutes found these.

Duralast FB551. Nearly perfect. Snug enough they will have to be pressed in. No idea what they are for..

$24 for 2 of them. 1 happens to have Teflon coating hence the darker color.

I also took the arms to the car wash to clean them up.

Update. Just found another # on one of the bushings. Clevite 61482. Dimmensions can be found here:

http://www.pirate4x4.com/tech/billavista/P...s_reference.pdf

[BodybyFisher]

Napa had no interest in searching thru bushings.

Went to AutoZone. They let me go in the back to search for a bushing that would fit.

In 5 minutes found these.

Duralast FB551. Nearly perfect. Snug enough they will have to be pressed in. No idea what they are for..

$24 for 2 of them. 1 happens to have Teflon coating hence the darker color.

I also took the arms to the car wash to clean them up.

Update. Just found another # on one of the bushings. Clevite 61482. Dimmensions can be found here:

http://www.pirate4x4.com/tech/billavista/P...s_reference.pdf

This is very cool that you were able to do this Logan. These appear to be the bushings that I use to press into the upper control arms of the 60's and 70's Cadillacs

[JasonA]

Interesting. As far as you know, these would also fit an "early" LCA, yes? No changes in bushing size...just (apparently) bushing durometer?

[Logan]

Interesting. As far as you know, these would also fit an "early" LCA, yes? No changes in bushing size...just (apparently) bushing durometer?

The GXP arms appear to be the early version LCA. Same as what is on the car now.

Turns out bushing is not quite as tight as thought. There was a burr inside the control arm where I hammered out the old one. That being said, just a few thousands looser. Very close. I was amazed to find something so close in 5 minutes.

I'll figure something out. Maybe knurl the bushing, press it in, and then tack weld to the inner ring. A little bit of machine work needs to be done on the bushing where it gets wider at the very top.

It'll be more like a Corvette arm. No 'Hydro' mounts on those..LOL.

I added another picture. Bushing can slide in to the arm until it hits the shoulder. Shoulder may need to be machined down slightly. Also, to the right you can see a new bushing next to the inner sleeve from the old bushing. Very close in height.

[JasonA]

I tried to find play in my OE front bushings last night and could find none. With a screwdriver, the only part that showed any give at all was a rubber or nylon part on the front side of the bushing. It was a very light-colored plastic otherwise, and appears to be original. According to GM VIS, no front suspension work has been done on my car in the past, so I'm 100% sure it's the original parts.

I get some steering wheel shimmy in the 65-72 MPH range; pretty much fits the M.O. perfectly. I did notice that the shimmy will change (reduce somewhat) during acceleration, and seems to be worse during deceleration. Because accel/decel will change the load on that front bushing, it appears that it really is the key to solving this issue.

Then again, I haven't even had the tires balanced since I bought the car (RFB or otherwise). I've literally done NOTHING to it in this regard yet, so I'm not ready to dive into something like front bushing replacement (yet).

[Logan]

This car has never felt right. Even at 40 mph.

It is much better then when I bought it..

I also now have a J 38792a EVA. It is pointing toward a tire issue.

See: http://caddyinfo.ipbhost.com/index.php?showtopic=15497

That being said, 4-5 sets of tires, all feel the same?

Have driven some other cars with simple install Michelins. No RFB issues. They ride better..

Currently, I have the time for the bushing experiment. Once the arms are fitted with the bushings. Should be a easy 4 bolt swap.

[JasonA]

My car has four very recent Michelin Energy MXV4 Plus (235/60R16). I don't know if they were "new" when I bought the car, but they had between 9-10/32". My suspicion is that they may have been take-offs that the dealer had from other vehicles. This is a large Cadillac dealer, and he said that all their used cars get "new Michelins". Sounds like an inventory grab to me.

Anyway, some have NO weight, and some have 1.5+ oz weights. I have no idea if they're balanced right or not, and have no idea if the tires are right. I had a road roar noise early on, that sounded like a wheel bearing, but it went away after a tire rotation. This sure didn't sound like a tire noise to me (it was ONLY in the 60-62 MPH range; faster or slower it was quiet). So I don't know about the integrity of these tires, though they are smooth and sound to 105 MPH (except for the 65-72 shimmy).

If you're starting a rental program with the EVA tool, PM me the details. I may want to rent it from you whenever you're done.