Front End setup help

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roughidle

roughidle

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I need some help from the masses on this one.... I'm re-assembling a '73+ bbj disc brake front end for my '68 Cuda. I'm starting from scratch on this one since I just had a bare shell to start with. I need to know what the proper order of installing the lower control arms/strut rods and getting it all to look proper when tightened down. I started to build it on the bench last night so I could install onto the car tonight, but I'm running into a couple main issues:

-Having a hard time tightening down the control arm nut - it keeps wanting to just spin the stud in the poly bushing. How can this be held so that it wont spin to finish tightening and torque?

-When I started cranking down on the strut rod nut, it didn't seem like the control arm was pulling straight on the control arm stud. It seemed to be trying to wrench to one side. I'm using new poly bushings on the strut rods, so I don't know what that's going to do to my measurement of the threads I took when I tore it down. I had measured how much thread was showing between the end of the strut rod and the nut at the front of the K-frame prior to tearing down, but I'm thinking that the new poly bushings might F with that measurement a bit, or can I just tighten down until I get the measurement I had to start with?

- I'm not going to fully tighten anything until I get the car on the ground, but I don't want to fight it too much once it's on the car.

- How do I go about trying to achieve a close adjustment with all angles; caster, camber, toe in and out without having any baseline measurements since I didn't have the car assembled in my possesion beforehand?

- Are all my questions answered in a tech manual that I don't have?

Thanks in advance!
 
Strut rods - Tighten the nut on the backside of the LCA first.

Poly bushings - they are known to throw out the LCA alignment.

Close Adjustment for toe - center the steering column to the steering box, take out 2 tapes and ductape them to a similar point on the tread, and clocking of the tires. Adjust turnbuckles.

Close adjustment for caster camber - cams all the way out in the front, all the way in on the back, check with a 2x4. 1x4, cut to the rim size, notched for the hub and stick an angle finder on there, it should be .5 degree negative.

This will be more than sufficient for an alignment, no need to take it to a shop.

Don't for get thrust angle alignment, these old girls are usually out 1/4-1/2 short on the passenger side. I took some straight 1x4 and put them behind the rear, and ahead of the front tire, and took a measurement side to side.
 
roughidle said:
- How do I go about trying to achieve a close adjustment with all angles; caster, camber, toe in and out without having any baseline measurements since I didn't have the car assembled in my possesion beforehand?

- Are all my questions answered in a tech manual that I don't have?

Thanks in advance!
Click to expand...

I can't help you with the tightening spinning issue as I'm not familiar with the poly stuff, but you can download a 72 (latest known to exist for free) shop manual here. Go thank AbodyJoe for that one

DO NOT use the 72 manual for wiring. You really should get yourself a 73 manual

http://www.forabodiesonly.com/mopar/showthread.php?p=1970088617

Do NOT use the factory settings for alignment, unless you are using bias tires. Use the "skosh chart" from here:

http://www.allpar.com/history/mopar/front-end-alignment.html

Search this site there's about a 1/2 zillion posts (not kidding) on alignment.

What do you have for tools, IE caster camber gauge?

Google things like "DIY alignment" You can buy inexpensive caster / camber gauges. All you REALLY need is camber, the gauge actually computes caster from turning the wheels, and you can do that yourself. If this is what you are going to do, I can elaborate LOTS of info on the www

Look through the shop manual and obtain the chassis measurements to check chassis square. Get the rear axle squared

For the front you FIRST establish ride height. Make certain the car is sitting level, with "everything" in place, even a tank of fuel, all put together with drivetrain, hood, etc.

Second, rough in caster / camber

I always rough in toe as well just to get things close, by eyeball

Then set caster / camber. This is very fussy as one affects the other. You have to realize, example, that if you need more caster, you have to lean the spindle angle to the rear, so you have to push the front of the A arm out, and the rear adjustment in. If you do this right, you won't affect camber too much. It IS a PITA for us old guys!!!!!

Toe is set last. About 20 ways to do this. You can build a simple tripod / scratch nail device to scribe the tires / tape, or come close just by blocking some 2x4's along the tires. They must be blocked up to spindle center. Two guys make this easier. You have to diddle toe then drive car and check that steering is centered. I usually eff this up by 1/8 turn of the wheel or more. You also have to take into account crowned roads.


http://www.forabodiesonly.com/mopar/showthread.php?t=183214


http://www.forabodiesonly.com/mopar/showthread.php?t=181851&page=2

http://www.forabodiesonly.com/mopar/showthread.php?p=1969910897

http://www.forabodiesonly.com/mopar/showthread.php?p=1970028465

http://www.forabodiesonly.com/mopar/showthread.php?t=226484

http://www.forabodiesonly.com/mopar/showthread.php?t=231627
 
If your using poly strut bushings with 67-72 struts it will push the lower control arm off of the stud as you tightening the front nut on the strut when the torsion bar is not in place and will bind the suspension once everything is put together, the poly bushings are too thick for the 67-72 a body struts, they are designed for B and E bodies.
You have three choices at this point:
1: use rubber strut bushings for 67-72 struts
2: buy adjustable struts or 73-76 struts
3: cut 3/8" off the rear strut bushing and use the cut off piece on the front side of the strut to take up the difference.
 
I bought this K frame assembled with the lower control arms and strut rods already in place and assembled. So I am relatively certain that these components are matched. My reason for disassembling them was to replace the worn components such as the strut rod bushings, control arm bushings, ball joints, etc. Also wanted to get everything blasted and powder coated. I got everything blasted and powder coated, but getting everything back together is turning into a battle and was just trying to get some direction as to whether or not I was heading down the right road or not.

I've read several different threads about lower control arm bushings etc, etc, but never really got the answer I had been looking for after about 1/2 hour of reading, so I figured I'd ask directly in a new thread. The bushing that came out of the lower control arm stud looks identical to what I'm putting in instead of it being a different color. I was mainly looking to see if there was an order of operations to putting them together that would aleviate my problems.

I've read that the poly bushings on the lower control arm have worked themselves out, and I've read of people who have had no problems. I ordered a poly kit, in the kit came the lower control arm bushings so I would like to just use them instead of having to deal with getting rubber bushings, pressing the old sleeves out, etc. I'm rambling. I'm rambling because I'm tired. Whatever.

Can anyone tell me if I should use the same dimension that I took for the threads on the strut rod now that I'm using new poly bushings there instead of the worn rubber ones? What I did is measure from the front end of the strut rod to the front edge of the nut. 21/32 is what I believe it was. Should this be the same dimension with the new bushings and all?

Thanks
 
And the other thing I noticed I was running into was when trying to wrench on the strut stud itself the stud was spinning inside of the bushing inside the LCA...
 
roughidle said:
And the other thing I noticed I was running into was when trying to wrench on the strut stud itself the stud was spinning inside of the bushing inside the LCA...
Click to expand...

there is no bushing on the LCA side of the strut. Presumably you are talking about the LCA pin spinning? Im pretty sure thats how my K frame tubes were ruined by the previous owner. I'll be welding up my new K frame this weekend. Im told in the linke below that the LCA pin is an interference fit to the tubes. Is yours?

I would install/tighten the pins on the K frame first. Hold the pin with thick leather in a big mo fo channel lock or something that wont gouge the pin then hit it with air. Make sure the pin is baby smooth if you nick it, because its a bearing surface with a urethane bushing. Then slide the LCA and bushing onto it. That mock up you should notice if the strut rod is too long if it pushes the LCA away from the K frame.

http://www.forabodiesonly.com/mopar/showthread.php?p=1970152202#post1970152202
 
That makes sense. I've got one of those strap wrenches I can try to hold the stud with. Then just slide the bushing on then slide the LCA onto the bushing. I've just been worried about damaging the LCA stud but hadn't thought about the strap wrench then hitting it with air to lock it up. Once it gets locked to the K frame I should be able to torque it from there without it spinning. Then as I understand it I should fasten the strut rod to the LCA and then install them both at the same time.

Anyone have any input on my measurement for tightening up the strut rods? I'm going to be diving back into this tomorrow night. I've had too much snow moving going on after my snowblower took a dump... I'm going to bed.

Thanks
 
The strut rods (on the bushing end) get tightened until the washers bottom out on the sleeves, no measurement required. The struts shouldn't turn once they're tightened into the control arms. If your strut rods have fine threads on the bushing side (67-72 style) then your going to have problems using poly bushings on them, they're going to push the lower control arm off the stud.
 
The threads are coarse thread on the bushing side so I think they're all 73+ components. I'm going to start wrenching here in a bit, I'll see where I get.

Thanks
 
You have an impact? I always had good luck rattling the LCA end of the strut first, that holds it from turning at the front end. Make CERTAIN you get the bushings oriented correctly, as some replacements like Moog go in much differently than OEM.
 
Can someone do me a favor and get me the dimension from the back side of the k frame next to the lower control arm to the nearest flange of the control arm itself. I need to either confirm or deny something. I'd like this to be from a stock setup. Preferably 73+.

Thanks
 
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