Rear Lower Control Arms...???

darkstar_one

Registered User
Hey,
Well since i was replacing my rear lower control arm bushings i said what the hell. Lets go to the junk yard and see if we can find some mark viii rear lower control arms since they are made out of aluminum and would save some weight. Anywho. I noticed that i would have to have spring perches made to have the original height. Also i noticed that these spring perches are usefull because they prevent the spring from possibly moving which looks doubtful at the moment. Unless you go off roading and the damn rear suspension has to move about a foot vertically... Anywho. I was thinking of taking home the rear airbags. But i said for what. I dont like airbags. I rather keep my springs. Anywho. Would it be worth switching over to the aluminum rear control arms and have some spring perches made or just keep my steel arms and just replace the bushings...

I also noticed that they have mark-viii air bag system delete kits. pretty wide springs for the rear and coil overs for the front i believe...

should i replace the arms and invest in one of these delete kits...
http://cgi.ebay.com/ebaymotors/Linc...wItemQQcategoryZ107063QQitemZ4629910726QQrdZ1
 
I think he uses someone else's pictures. In his item description: "The parts are used take offs...The kit may look different from photo, but is the same style parts. "

So he must be using used T-bird suspension parts for the swap.
 
How much lighter is the MK VIII LCA than the steel SC one? Is it worth the trouble of hunting one down, ripping it out and putting it on?
 
It is a lot lighter. I had the spindle on one of the arms with the bearing and hub in place, it was lighter then just the arm alone from the t-bird.

Also, is there a leveler in that kit from evil-bay?

Chris
 
I am doing the swap now. I will weigh them on a bathroom scale and post the results. I will also weigh the mark8 diff vs the one from my XR7
 
send an email to ThomasA, he makes perches for the Mark 8 arms so you can use your stock springs
 
Keep in mind this was done on a bathroom scale.
The stock cast arms from my 90 xr7 weigh about 25 lbs each.
The Mark 8 arms weigh in around 15-16 lbs.
The cast rear end from my Xr7 weighs 80 lbs.
The mark 8 rear weighs 60 lbs.
 
I got a set of Mark VIII swing arms with perches total weight 40lbs for both sides (17.5 for each swing arm & 2.5 for each perch) stock swing arm is 25lbs each 50lbs total (steel cast not stamped) Total weight saveings of 10lb I drilled out the perches to save 2lbs for a total of 12lbs from the switch.
 
You should notice a difference though, 10lbs a side does not seem like much, but when you think that putting heavier wheels on causes a rougher ride, you will understand.

Chris
 
What do you cut them with? I plan on eventually trying to go with a spring over kit that eliminates the heavy spring and perch. Until then, hook me up with your secret to cutting it.

Chris
 
no164ford said:
I got a set of Mark VIII swing arms with perches total weight 40lbs for both sides (17.5 for each swing arm & 2.5 for each perch) stock swing arm is 25lbs each 50lbs total (steel cast not stamped) Total weight saveings of 10lb I drilled out the perches to save 2lbs for a total of 12lbs from the switch.

Yes, I forgot the perches. Only a fair comparison if you add their weight in.
 
Quick Question

I have easy access to a Mk viii in my local u-pull-it. I have S/T lowering springs and coil spring isolators from spinning wheels-SC. Do you think I'll need spring perches with this setup. BTW, my spring isolators are huge. They don't fit the S/T springs nicely. I had to wrap electrical tape around them to keep them together for installation.
 
Word to the wise, if you are going to u pull for these, the cam bolt on the rear of the control arm was a show-stopper for me at u-pull. There was no way to get enough leverage on that nut under the car. I had to give up after spending a couple hours on it. I ended up going to to another yard a block from u-pull
and they delivered the mk8 arms and pumpkin to my house 60 miles away for free. I paid 200 for the arms and pumpkin. I had to fight the cam bolt out at home because they had just torched the subframe off, but at least i was able to rig it up so that i had good leverage (ended up snapping one of the cam botls because it was seized so hard)
 
yes you need the perches, you also need the hardware for the M8 arms, they are different then the ones used for the steel arms
 
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