Lower A-arm boxing, Del-a-Lums

[maineSS]

Hi everyone:

I'm doing the B-body spindle mod, and was considering boxing
my lower A-arms & using Del-a-Lum bushings. Two possible
problems for daily driver use:

1) Corrosion- The bushing sleeves are anodized aluminum,
and will be press fit into steel A-arms. I doubt the anodizing
will survive the press fit- so it looks like severe corrosion in
the presence of water. Anyone have this problem? I drive
year round in a snowbelt state (ME).

2) Cracks/slotting- Boxing the A-arm & using solid bushings
will stiffen it up noticeably. Will it pound out mount boltholes
or flex the mounts to the point where cracking is guaranteed?

The 4th Gen Camaro has boxed A-arms with rubber bushings,
and NASCAR used to box A-arms in the 70's. I've thought
about gusseting the rear mount, and tack welding a nut
on both sides of the bolt (one bored out)- will this be enough?
The problem with using some of the fun racing tech is that race
cars and street cars inhabit different worlds- you have to know
whent to quit! Thanks.

 

[GNVAIR]

Boxing of the lower control arms on the front is really unecessary, but if you want to do it, I would recommend 1/8" steel plates welded beneath the bushings on the lower part of the arm. Just small strips should do it.
I have Del A lums on my GN and they are great. If you are worried about the anodizing coming off then I would just touch them up with some paint and coat the area where the bushing is pressed into the control arm.

 

[maineSS]

Del-aLums/boxing

Hi Lee;

The plates I made start at the BJ area and end where the
bushing mounts start to curve. It took about 5 hrs with a
4" grinder (each side- They're different) to fit them after
torch cutting. I made plexiglass templates of the finished
plates so I can cut to finished dimension if I need to do it
again. The idea is to resist A-arm deformation under heavy
spring pressures used in racing. The F-body spring rates
of 700+ lb/in may be the reason it's used on the 4th-Gen
Camaro.

The Del-a-Lums are a tight fit from what I hear, so paint
or 1000th inch thick anodizing won't survive the press fit.
Bare aluminum next to steel just disappears- one classic
problem was Landrover body mounts- aluminum body +
steel frame + time and a big bump = "WTF was THAT!"
(Famous last words of the Mayor of Hiroshima).

BTW- how do you get complete threadids from this site-I've
tried linking, but never can get it to work.

 

[motorhead]

Once again... Lee and I share different opinions. We are special people.

I had my lower A-arms boxed earlier this summer and added DALs. And like yourself I am running F-body springs.

Arms:
- I used strips of 1/8” thick plate… 2” wide. The strip steel was used because when forming the plate to the arm (which isn’t flat or true) it tends to pre-flex the arm.
- Box the arms before pressing out the old bushing. I actually cut the shells out.
- Support the one open end of the arm with some sort of a brace… it can still collapse.
- Leave space for the Zerk fittings… you may still have to notch the plate a hair to get the grease gun in there for service.
- Leave room for the swaybar endlinks too.

Bushings:
- Freeze them for 24+ hours… take to your hydraulic press in a cooler full of ICE!
- Remove the inner materials before pressing.
- Heat the arms’ holes up, add some WD40, and press quickly. You’ll need a “receiver” like when doing ball joints.
- Yes, that anodized coating is coming off… I left the AL bare & greasy… but, you can paint them.

Springs:
I am using a set of factory V8 F-body springs with 1 coil cut… there is a good chance the spring rate is well over 800lbs/in. If I put all of my force on it… it budges about a 1/2”

The factory arms are left unboxed for the same reasons rubber bushings are used… ride quality. That and it is cheaper to create a simple tooled “U” part over a boxed piece.

I have been meaning to snap a few pics of my arms… guess I should borrow the company digi-cam, eh?

The car handles like a dream… I have ZERO deflection in the front suspension (tubular uppers, with DAL-style bushings also) and there are no noises up there either.

Also note that reinstallation of the DAL’d arms may be a touch tougher than rubbered arms… they have NO give to them… and you may have to be tricky to get the “nylon” (delrin, IIRC) washers to stay in place.

HTH,