Question: Not enough Caster adjustment in my big block Duster.

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SlimPikins

SlimPikins

Pikins, Slim Pikins.
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I have a 73 Duster with a 440 that was a slant 6 car originally. It has the original K member. It has manual disc brakes and power steering. I picked up the car with the big block already in it. I completely redid the front end with a rebuild kit from PST. I took it in for alignment and they said there was not enough caster adjustment in the car. I got it back and it drives horribly. I wanders all over the place. I heard that doing a disc brake conversion can mess things up if the right parts are not used. Any insight would be greatly appreciated!

Slim.
 
Any chance you have another choice for an alignment shop? A tech that knows what they're doing should be able to make it drive decent, even if enough caster can't be achieved with adjustments.

Moog makes offset upper bushings to provide add'l caster if that's the issue. Part # K7103
 
Set the ride height FIRST. Then put the front cams all the way out and the rear all the way in (that is the orientation of the bolts). Then bring the rear cams out until you have about 1/2 degree of negative camber. That is the most positive caster you will get out that car. The more rake (front low/rear high) the less caster you can get. Set your toe and you're ready to hit the road.
 
The only alignment guy I ever used that could make my Mopars drive like new died in a plane crash 8-9 yrs ago .
I once had my dart aligned by a leading frame and alignment shop here in town . It drove like crap so I brought it right over to the guru a few towns away . When I picked it up the difference was night and day !!!
 
Is it possible that someone can post a few pictures of the cams positions and show via diagram the caste/camber and toe aspects of this operation. I think it would be a great help for new to this operation guys trying to align there fronts themselfs or just good enuff to get it to a shop for best alignment.
 
The best way is to "mark" the cams in the position they were in before you disassemble the front end. Put them back in that position when you're done. If the alignment was close before you started, then it will be close enough to get to the alignment shop.

Every individual car is different and you can't set them all the same........
 
There are companies making adjustable strut rods that can give you some more caster adjustment.
One local guy in Atlanta is Whips Parts Co. that makes beefy ones for A bodies for about $175. with good parts.
Tell him I sent you.
404-455-2971 or [email protected]
 
Caster specs are overrated on these old Mopars. People are spending lots of $$ to increase caster and won't feel much of a difference IMO. Don't believe all the internet hype.
 
Factory caster specs are downright scary with radial tires. 2-3 degrees positive caster provides much more control and better feel.

Yes, every car is different, but if you start from the specs I provided you will get the most positive caster available for that specific car.
 
i found on my project a way to cheat a little more.

i used 5/8 hardened steel washers (two of them, each bolt) between the lower ball joint and spindle to build in some negative camber. used the 7103 for max caster with stock uppers (all on FMJ spindles for better negative caster gain).

set the upper eccentrics to masx positive caster, and with this ball oint shims my specs came out to 4 degrees positive caster, 1 degree negative camer. tis is also at a ride height of 24 inches to the top of the wheel arch on 25 inch tall tires.

so, grab a couple of tools, some washers, and uca bushings. do the alignment yourself, and know what the results will be.

after learning to do my own alignments, i will alsmost never pay to have someone else do them.

Michael
 
rumblefish360 said:
Is it possible that someone can post a few pictures of the cams positions and show via diagram the caste/camber and toe aspects of this operation. I think it would be a great help for new to this operation guys trying to align there fronts themselfs or just good enuff to get it to a shop for best alignment.
Click to expand...

Here's one I made.
 

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6pk2goDemon said:
Caster specs are overrated on these old Mopars. People are spending lots of $$ to increase caster and won't feel much of a difference IMO. Don't believe all the internet hype.
Click to expand...

About $50 from Rock Auto. $25 more than stock rubber bushings. And about $6 more than poly upper bushings.
 

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autoxcuda said:
About $50 from Rock Auto. $25 more than stock rubber bushings. And about $6 more than poly upper bushings.
Click to expand...

Yep, those are the Moog bushings I referred to in my original post. Great choice if caster is an issue. It's an easy and inexpensive upgrade for these cars 8-)
 
Thanks for the input guys! I'm at the track this weekend racing the wifes car and will check into this when I get home.
 
6pk2goDemon said:
Any chance you have another choice for an alignment shop? A tech that knows what they're doing should be able to make it drive decent, even if enough caster can't be achieved with adjustments.

Moog makes offset upper bushings to provide add'l caster if that's the issue. Part # K7103
Click to expand...

Sorry, but too much caster will cause the car to wander and no amount of toe or camber adjustments will stop it. Think of it as a motorcycle. The front fork has a slight (or serious) rake to it. This allows it to track more easily. If the front fork was straight up and down, it would track terribly. You would have a hard time keeping it straight while driving. If there isn't a kit made (and it sounds as if there is) you can usually make a shim fairly easily, sometimes from a washer if it is shim style. If it uses eccentrics, you will have to find something that will work. A little ingenuity goes a long way!
 
How do I get my 1/2 degree of neg camber from my shop tools .
 
I am installing my Dana 60, mono leafs and caltracs. My brother came over with a set of adjustable strut rods he had no use for since going to a b body. I am going to throw them in and I might play around with the adjustments and see what it does to my caster. I don't have a caster issue, but since I have access to an alignment machine I believe I will play around and give feedback.
 
Well I have done some research and most of it confuses me.
I was told that when doing a big bolt pattern disc brake swap that you cannot use parts from 73 or later B bodies because it will mess up the geometry. I have no way of knowing what parts I have. I found a part number on the lower control arm which when I Google shows up as an A body part number, but I cannot find any usable numbers on the upper control arm or spindle. I am including some crappy cell phone pics of how my upper control arm is adjusted now, and pics of the spindle in my car. I contacted RMS about there adjustable strut rods and/or adjustable upper control arms. They said that they don't recommend using the adj. struts for caster adjustment, but said the adj. upper cntrl arms will work great. I have a chance to buy what's suppose to be the right front end parts for 125$, but what guarantee do I have that they will be right. I hope this info or pics might help someone shed some light on what I need.

Thanks,
Slim.

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There shouldn't be a problem with those spindle, even if they are the taller ones. Start with the cams adjusted as described above and adjust to 1/2 degree negative camber with the rear cam. You can do this at home if you have the tools to measure or find a good alignment shop that will follow thses instructions.
 
Jim Lusk said:
There shouldn't be a problem with those spindle, even if they are the taller ones. Start with the cams adjusted as described above and adjust to 1/2 degree negative camber with the rear cam. You can do this at home if you have the tools to measure or find a good alignment shop that will follow thses instructions.
Click to expand...

The alignment shop I took my car to is very well trusted. The owner is a racer with some really nice bracket cars, and his alignment guy does ALL the work on his cars, plus most of the racers in the area. He did everything he could to align it. I ended up buying a set of adjustable upper A arms from RMS. I hope that will fix my problem totally.

By the way, I contacted the original owner of the car and he said they never replaced the front brakes, they came on the car originally.
 
Any chance you have a printout of the specs from the alignment?

Very difficult to diagnose over the net....way too many variables involved.
 
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