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stefan 08-11-2010 11:05 PM

trimming lower control arms
 
Hey guys im sure this has been asked a thousand times,so ill ask once more,i need to trim my lower control arms but i need to know where and how much is safe,i really appreciate any help.

87chevy.com 08-11-2010 11:14 PM

Re: trimming lower control arms
 
In my experience, I will never do it again. I trimmed the front lower control arms so I could run Centerline 15" wheels... after say 2 months control arm failed on the freeway and I went from the far right lane, 3 lanes over into the conrete wall... wasnt hurt that bad... somehow I missed everyone, Someone was watching over me that day I tell ya. Just fatigued due to trimming too much off the "rain gutter". I would rather buy a spacer of some sort, or just get bigger wheels.
clint

SCOTI 08-11-2010 11:23 PM

Re: trimming lower control arms
 
Quote:

Originally Posted by 87chevy.com (Post 4134771)
In my experience, I will never do it again. I trimmed the front lower control arms so I could run Centerline 15" wheels... after say 2 months control arm failed on the freeway and I went from the far right lane, 3 lanes over into the conrete wall... wasnt hurt that bad... somehow I missed everyone, Someone was watching over me that day I tell ya. Just fatigued due to trimming too much off the "rain gutter". I would rather buy a spacer of some sort, or just get bigger wheels.
clint

How did you 'trim' the a-arm?

87chevy.com 08-12-2010 06:57 PM

Re: trimming lower control arms
 
think we used a grinder... I think the problem was they were 3" drop spindles on aluminum wheels and it required to chop a lot of the gutter material... that gutter material is what gives the ball joint area its strength... thats where it failed... essentially bent the metal back and fourth untill it let go.
clint

lolife99 08-12-2010 09:05 PM

Re: trimming lower control arms
 
I've trimmed every 67-87 lower control arm on every truck I have lowered.
(My trucks and others)
Never had a failure of any kind.
I've done this mod since the 1980's.

lolife99 08-12-2010 09:12 PM

Re: trimming lower control arms
 
3 Attachment(s)
The area with the blue masking tape has already been trimmed.

The last picture is a stock "un-trimmed" lower a-arm, with the area "to be trimmed",... marked in red.

N2TRUX 08-12-2010 09:42 PM

Re: trimming lower control arms
 
I have trimmed several sets with no issue, but I have also heard of them cracking. My solution was to trim as needed then add a boxing plate on the bottom. After that I came up with the best solution in my opinion. I no longer wheels small enough to require the arms to be trimmed...;)

mooseknuckles 08-12-2010 10:38 PM

Re: trimming lower control arms
 
I had no choice but to trim mine they were rubbing into the bead on my tire, the first time I drove it thy peeled off my wheel weights!

54Caddy 08-12-2010 11:53 PM

Re: trimming lower control arms
 
??the picture with the red markings is the area that can be trimmed off correct??

SCOTI 08-13-2010 01:27 AM

Re: trimming lower control arms
 
Quote:

Originally Posted by N2TRUX (Post 4136314)
I have trimmed several sets with no issue, but I have also heard of them cracking. My solution was to trim as needed then add a boxing plate on the bottom. After that I came up with the best solution in my opinion. I no longer wheels small enough to require the arms to be trimmed...;)

Too much backspacing will still cause rubbing even w/large diameter wheels. Like Lolife99, I've done it numerous times on different year models. I drill a hole where I want the lip to start/stop. Then w/a cut off wheel, I trim the offending material away.

Lee H 08-13-2010 10:54 AM

Re: trimming lower control arms
 
I also trimmed that area on my son's truck a few years ago. At each oil change we rotate the wheels, and check the area for signs of failure. So far so good.

lolife99 08-13-2010 01:38 PM

Re: trimming lower control arms
 
Quote:

Originally Posted by 54Caddy (Post 4136574)
??the picture with the red markings is the area that can be trimmed off correct??

Correct.
You still have to check for clearance issues.
Set the truck on the ground after trimming, and turn the wheels in both directions to verify that no part of the a-arm will make contact with the wheel.

72BlckButy 08-13-2010 05:25 PM

Re: trimming lower control arms
 
4 Attachment(s)
Here's what you'll end up with...

Attachment 621034

Attachment 621035

Attachment 621036

Attachment 621037

54Caddy 08-13-2010 08:34 PM

Re: trimming lower control arms
 
i was going to completly cut off the bump stop and the metal, would that be a bad idea. Basically cut off the rest of what is showing on the picture above. Going with bags.

lolife99 08-13-2010 09:03 PM

Re: trimming lower control arms
 
The only part I leave is the "steering stop" for the spindle.
Some people remove all of it.

stevencvn72 08-13-2010 09:05 PM

Re: trimming lower control arms
 
Not to jack this thread, but did any of you have trouble with the LCA clearing the disk break dust shield? And yeah...I was also wondering about the question above with the steering stop.

SCOTI 08-13-2010 10:26 PM

Re: trimming lower control arms
 
Quote:

Originally Posted by stevencvn72 (Post 4137902)
Not to jack this thread, but did any of you have trouble with the LCA clearing the disk break dust shield? And yeah...I was also wondering about the question above with the steering stop.

Some do clear, some don't. It's easy enough to tweak or trim the 'shield' for clearance if it interferes.

63chevyll 08-13-2010 10:56 PM

Re: trimming lower control arms
 
u normaly grind the stop off also, i like the travel

SCOTI 08-13-2010 11:01 PM

Re: trimming lower control arms
 
Quote:

Originally Posted by 63chevyll (Post 4138080)
u normaly grind the stop off also, i like the travel

Grinding the stop off only increases the problem if the wheels rub. Once the stop is gone, you have to remove more material because the steering arc will slightly increase (close to, or in bind).

63chevyll 08-14-2010 09:50 PM

Re: trimming lower control arms
 
Quote:

Originally Posted by SCOTI (Post 4138091)
Grinding the stop off only increases the problem if the wheels rub. Once the stop is gone, you have to remove more material because the steering arc will slightly increase (close to, or in bind).

see my avatar pic, it was on my race truck, travel was needed

Mike J 08-14-2010 11:22 PM

Re: trimming lower control arms
 
I cut the stops off completely on mine, but even with the 5.5" lowering and 15x7 steel wheels, I didnt have to take off any of the lip- I guess it really depends on the backspace of the wheel...

lolife99 08-14-2010 11:55 PM

Re: trimming lower control arms
 
Yep.
Usually a 15" wheel with more that 3.75" of backspacing,... will require a trim.

SCOTI 08-15-2010 02:31 AM

Re: trimming lower control arms
 
Quote:

Originally Posted by 63chevyll (Post 4139470)
see my avatar pic, it was on my race truck, travel was needed

Read my statement again.....

Quote:

Grinding the stop off only increases the problem if the wheels rub. Once the stop is gone, you have to remove more material because the steering arc will slightly increase (close to, or in bind).
If it's not a problem already.... good. But, it could become one so be on notice.

54Caddy 08-15-2010 10:47 AM

Re: trimming lower control arms
 
well i looked at my truck and with the wheels fully turned nothing hits the stop, so im thinking just taking it all off.

ZUBZ 09-07-2012 08:27 AM

Re: trimming lower control arms
 
Very nice thread guys, thanks for the info and pictures.


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