TCCoA Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter #1
I have a 1994 lincoln mark 8 IRS in my old ford truck, the whole thing sits much lower than a stock mark 8 is. I went to get an alignment today and the IRS went well except the negative camber is way out. I have it maxed out and am still getting 2.2* negative camber any ideas on how to fix this? Can I just get a different cam bolt to put in the upper control arm? Can I just elongate the alignment hole for the upper control arm? Any thoughts?
 

·
Registered
Joined
·
563 Posts
I have (I think) the same problem with my 300zx. On that car, the rear camber adjustment is very limited as the arm is fixed to the subframe. I need to find out how far the camber is out (my tires lean inwards at the top) so I can order a template from z31parts.com to fix the camber I got with my super stiff lowering springs. I cant recall if you elongate the hole or just drill another, but I am guessing that you will need to do something similar (although I don't know of templates for the tbird). A good custom shop should be able to help.
 

·
Registered
Joined
·
1,095 Posts
My camber in the rear is maxed out as well, and I'm only dropped ~1.5". One side was was worse then the other actually, but alignment was still in spec on the bad side. I was thinking maybe I could put the arm in a big hydraulic press and bend it straight just a tiny bit. Should only take a little bit of straightening to make it long enough to correct the alignment.
 

·
Registered
Joined
·
623 Posts
It sounds like you have quite the custom setup. The best solution to this problem in my eyes is a few more custom parts. I would make/get some longer upper control arms made. Your truck must be very low. The camber adjust on these rear ends has a fairly wide travel. I dont know if there's enough metal to safely elongate the hole enough to gain even a full degree.
 

·
Registered
Joined
·
743 Posts
I have a 1994 lincoln mark 8 IRS in my old ford truck, the whole thing sits much lower than a stock mark 8 is. I went to get an alignment today and the IRS went well except the negative camber is way out. I have it maxed out and am still getting 2.2* negative camber any ideas on how to fix this? Can I just get a different cam bolt to put in the upper control arm? Can I just elongate the alignment hole for the upper control arm? Any thoughts?
First of all....I have been following this project of yours for quite some time, and have directed a couple of friends into following your truck build, as they both own 1970's F100's....I've even dabbled with the thought of buying a friend's 1968 F250 2wd and doing the same thing to it....


It sounds like you have quite the custom setup. The best solution to this problem in my eyes is a few more custom parts. I would make/get some longer upper control arms made. Your truck must be very low. The camber adjust on these rear ends has a fairly wide travel. I dont know if there's enough metal to safely elongate the hole enough to gain even a full degree.
I've seen pictures of the truck; it's not that he's lowered it, I think the problem is that the MK8 rear suspension cradle attaches directly to the frame, and those attachment points are higher up in the truck vs. the original MK8 that it came out of; think of a MK8 with the body channeled lower over the 'frame' and I think that might be a better explanation as to what's going on.


Sir, I sincerely thank you. I haven't lowered my Thunderbird yet, but I thank you for exposing a potential problem with dropping it (yet another gremlin to face, the first being the rear swaybar endlink problem). Your car is displayed upon my desktop as I speak; I wish to create something similar to your car in setup, but keep it a bit simpler under the hood (N/A 408 stroker planned)....I waver back and forth between selling and keeping this car, as it seems like everywhere I turn, there is a potential headache with every mod I'd like to perform to this car; It would be so much simpler just to snap up a Fox-body Mustang and just mod that; but I don't really fit in those cars (too tall, and shoulders too wide), and of course, this car is already paid for.

It can be done....thanks for showing that.

Okay, now back to our regularly-scheduled programming...
 

·
Registered
Joined
·
10 Posts
Discussion Starter #7
Yes Evilmoose is correct, the main problem is that the suspension is in a truck and the location throws some things off. I have been thinking about it and the only solution I can come up with is to cut the control arms and make them slightly longer.

I am thinking I can cut the upper control arm and (using an angle finder) set the wheels at a 90* angle to a level surface (my shop) and weld the control arm back together. I could even set the control arm to the middle of the camber adjustment and then lengthen and weld it all back up with the tire at 90* to the ground so I have some adjustment left in the camber.


Does this sound like a bad idea? good idea?


Thanks for the link 392 bird good info.
 

·
Registered
Joined
·
743 Posts
Yes Evilmoose is correct, the main problem is that the suspension is in a truck and the location throws some things off. I have been thinking about it and the only solution I can come up with is to cut the control arms and make them slightly longer.

I am thinking I can cut the upper control arm and (using an angle finder) set the wheels at a 90* angle to a level surface (my shop) and weld the control arm back together. I could even set the control arm to the middle of the camber adjustment and then lengthen and weld it all back up with the tire at 90* to the ground so I have some adjustment left in the camber.


Does this sound like a bad idea? good idea?


Thanks for the link 392 bird good info.
I have another idea; build an additional 'subframe' to go between the suspension cradle and the frame....simply build it as thick as you need to lift it up to the desired height, and then weld it back together. I didn't focus too much on what you did to attach the rear subframe, I was too busy drooling over your work with the CV front clip, as what you did could make the CV piece the new 'Mustang II' suspension clip of the 21st century. If I end up giving the T-bird a new home, your work opens up a lot of possibilities for me, as I do have a fondness for 1967-1972 F100 2wd trucks....
 

·
Registered
Joined
·
7,758 Posts
Here's my thoughts:

Alignment specs should not be impacted; no matter what the rear assembly it is bolted onto so I don’t see how “the main problem is that the suspension is in a truck and the location throws some things off” would matter at all.

The camber is strictly a function of the lower A arm, the upper A arm, the knuckle, and the spring height. All of which are attached to the assembly.

I can’t remember if you’re using springs or if you’re still using the airbags. But if you can’t get the proper alignment, either the springs are too short or the air bags are too low.

I see multiple possible solutions:

1. Move the A arm pivot points on the subassembly as needed. (I like this the best as it is simply cutting and welding pickup points.

1. Slot the knuckle as was earlier mentioned.

3. Modify the upper A arm as you mentioned. (I like this as the second best solution, but you have to make sure the arm still clears the assembly on the top (that’s why it’s curved) and that the half shaft fits into on the bottom during suspension travel.)

4. Install the proper length springs and change the chassis mounting height to get the ride height you’re after. (But this could have a domino effect on a lot of other things…)

But definitely just my opinions! I’m not up to date on how far along you are, so some of those solutions may not be feasible. :thumbsup:
 

·
Registered
Joined
·
743 Posts
Here's my thoughts:

Alignment specs should not be impacted; no matter what the rear assembly it is bolted onto so I don’t see how “the main problem is that the suspension is in a truck and the location throws some things off” would matter at all.
I think the rear of the truck was 'lifted' to compensate for the low ride height....which might indeed affect camber settings if taller/heavier springs were used, or more pressure was put into the rear airbags to get the truck back up into the air where it is supposed to be....moving the cradle downward would allow normal air pressure/springs to be used so the suspension could rest at the 'normal' position, instead of being hoisted into the air as far as possible to keep the back of the truck from bottoming out.

If the MN12/Lincoln IRS goes into positive camber gain when it's compressed/lowered, then it's probably a pretty good bet that it goes into negative camber gain when it's raised...
 

·
Registered
Joined
·
623 Posts
Let's see some pictures... I am interested in how this thing is set up. If the upper and lower arms are still bolted to the factor subframe that is not cut up/altered the only reason it would be so negative is if it is pretty darn low (from short springs).

This is assuming the control arms are still bolted to an unaltered subframe...
My car is lowered almost 2 inches in the back. When I aligned it I set it to -.7 degrees (camber) on both sides. I had about another .2-.3 degrees in it to go more positive had I wanted.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #12
A few pics of the install, as you can see I am using the stock subframe with the original mounting points cut off so I could weld it to the boxed truck frame. I did cut about 1.5 coils from the springs and thats why it sits lower now. I am still leaning towards cuting and extending the upper control arms to make the wheels sit 90* to the ground and adjust camber from there.










Using this for motivation LOL (sorry cant help but post that pic, its my favorite)

 

·
Registered
Joined
·
623 Posts
From the pictures it appears that the stock mounting points were retained for the upper and lower arms, am I correct? If this is the case, it does not matter what is mounted above the subframe (unless it's 8000 pounds, exaggeration) in terms of your camber problem. It doesn't matter if the body was bolted to the subframe with 7 inch spacers or channeled around it, as 94 daily driver pointed out. I think your best option is to try 392Bird's suggestion. If that doesn't get you enough positive camber go with the lengthening of the upper arm plan. I'm sure you could a cheap set to elongate the holes on to see if that gets you enough positive. If that doesn't work, modify/make new upper arms. Of course there is the option of putting longer springs in as well. Good Luck, looks like a cool project.
 

·
Registered
Joined
·
10 Posts
Discussion Starter #14
Thanks, I am having the camber problem because I cut so much off the stock super coupe springs. I installed the suspension so that it was basicly still in a lincoln mark 8 then cut the springs from there to get the desired ride height
 

·
Registered
Joined
·
219 Posts
interesting . was looking for threads on suspension woes from lowering my 95 , and run across another person who has done something i'm getting ready to do to my 53 1/2 ton . in my case , the 53 , i'm just cutting the front mounts of the sub , and moving them in to bolt into the bottom of my frame , the rear ones are already the correct width . not looking to lower it to much as the roads here suck . well i keep saying the 53 it's in the air as i have a spare early frame , a roller , and found another cab , well .... don't know if i got the gut's to chop up ol' faithfull .that flatty powered beast has done everything i have ever asked of it . problems i'm running into is the front suspension on my brain fart as i'm determined to use the 91 birds front suspension as well and not use the dain struts ................. you got a link to your 70 build ?????????????? ps i just parted out a 70 3/4 ton long bed express stepside . if it hadn't been so eaten up i'da kept it ! love the bumpsides and dent sides . kept the fe and 4 gear though ............
 
1 - 15 of 15 Posts
Top