Jordanf

Does anyone else have issues with the UCAs bottoming out on the chassis that's shown in the pic?

91 LS400 semi slammed on BC coilovers.

Can I notch this area with a die grinder, or is it too structural to mess with?
I tried hammering that area but doesn't seem to do much and there's almost no room.

PureDrifter

iTrader: (10)

structural, leave it alone.

At worst, hammer yourself a little clearance, but you def don't want to be cutting much there.

TMAdash1

iTrader: (1)

higher spring rates and stiffer dampening are your friends

dicer

I keep wondering why people always want to mess up the good cars and trucks?
http://carpaper.net/old-citroen-cars...s-picture.html
Here would be a good car to do what ever you wish to.

timmy0tool

iTrader: (7)

yes! OP, you can try and bring the spring preload up a bit to stiffen the coilover. this should not change your ride height.

spin the lower spring perch up a few turns (maybe only 1 full turn since it's under tension as it is). of course be sure to unlock the locking collar (under the perch) first.

Jordanf

I currently have an issue with my front control arms or suspension bottoming out/clunking on my 91 LS400 while driving over breaks in the pavement usually at lower speeds around town, and especially with passengers in the car. It drives extremely smooth otherwise.

The car is sitting pretty low on BC coilovers, tucking the top of the tires . I have the front UCA clearance holes cut out on the strut towers.

It appears the front arms of the UCAs are hitting the chassis which is causing the bottoming out feeling



Based on some advice on here I went ahead and ended up swapping out the 12kg / 8kg BC springs for some stiffer 16kg / 12kg Swift springs which definitely helped, although the issue was still there.
I then bought some OEM strut rod cushions and trans mount to replace the old stuff, which again help a bit, but didn't solve it.
I'm keeping this car low, so raising it isn't an option.

Any other suggestions?

dicer

I thought that having those problems was just part of the coolness of lowering a car.
At the rate these cars are being ruined some day I will have a couple of million dollar cars.
I wonder what the name of the reality show will be that restores old LS400's back to factory spec's kinda like
Grave yard cars does with old Mopars.

Shmee

iTrader: (3)

Dicer,
if you have issue with what people do to their cars, please feel free not to post to such threads.
Both of your posts in here are neither informative nor helpful.

If you have such a beef with how people are modifying these cars, start your own thread and post your opinions in there. Otherwise it is my suggestion that you stop posting in threads that aggravate your single-minded curmudgeony opinion of how these cars need to be treated/modified.


@Jordan,
That mark could just be a red herring sending you on a merry chase with no solution
Clean up the spot on the frame where you think you are hitting and put some paint or a small spot of grease. If you get transfer to the UCA, then you are probably hitting there. If not, you have other problems.

Do a thorough checkover of your suspension and see if you have any other issues you have over looked. UCA bushings/joints as well a sway bar links and bushings can cause clunks as well. A blown LBJ will also cause a gnarly clunk if bad enough.

Jordanf

thanks Shmee, I'll look over the other suspension components

phenomeno

iTrader: (1)

After research on several groups on facebook LS400 pages, Ive found that this knock is common and others have offered several work arounds such as cutting of metal area around strut towers to installing rubber on metal part to lessen the knock. Apparently its the upper control arm that is knocking against the body of the car. You can buy the correct way of fixing it by buying front upper control arms like "SerialNine" but they go for $530.00....sheesh

what did you decide to do to correct tihs issue?

Suprjdmbro

even with s9 fucas i hit that area..I notched my brace where the fuca was hitting.

dicer

I'm being informative. The cut hole looks like RTV was smeared into it. A better choice would be some primer then a rubberized under coating. RTV always seems to get to a point where it just comes off, unless the newer stuff holds up better now.
And I'm surprised that with all the other aftermarket suspension parts that out fits have come up with, that someone hasn't come up with a control arm and knuckle assembly that prevents all the contact problems that you folks have.

sndlight

Saw this on Facebook....

sndlight

And this... But it looks very very dangerous. I would worry that the structural integrity of the vehicle is compromised.

dicer

Your right, that is a mess. And that shorter spindle knuckle is a way better deal, and would eliminate all the problems. Gosh on the last picture notice how they cut into the control arm near the ball joint. And you'd think that having a huge window like that in the tower would make it flex and make an oil canning noise.
Gosh maybe my calling would be to lower LS's for people and make it so they wouldn't get so messed up.

I think that knuckle was cut and welded, and that is okay as long as a good welder metal person does it.
Even too lazy to cut those wire tie ends.