RMS UCA fitment problem with 17x8 bullitt rims...

[mopardude318]

Hello friends...I am having somewhat of a problem with my front suspension going together...This is for a 68 cuda...I did a 73+ disc brake conversion, and used RMS UCA and strut rods. It's all pretty much going back together, just having a couple minor fitment issues.  First I had a problem w/ outer tie rod clearance with the rim, so I used a 3/8" spacer. Fixed, no problem..The rim goes on fine now, but at full lock, left or right, the rim comes in contact with the RMS UCA. I adjusted the cam bolts a few diff. configurations, with no luck. I'm thinking maybe these UCA's won't work for my application because they are too wide, about 3 1/2 inches wider than stock a-arms.

Here are the pics. The first two shows the rim hitting the tubular upper control arm at full droop.




This pic shows how much more I COULD turn if the rim didn't hit the UCA. (about 1 more full turn)
Note the steering stop doesn't hit the LCA stop, as it should.



Here is a pic at ride height, again, the rim hits the UCA.


It seems that I will not be able to use the RMS UCA because they are too wide, more shaped like a "U". If you were to look at the Firm Feel tubular UCA, they are narrower and shaped like an "A", more or less. And it seems I will have more clearance if I use the Firm Feel UCA...

Here's the Firm Feel unit, its narrower...


I am just comparing the 2 A-arms, And maybe I am doing something wrong...I am no way in any shape or form bashing on Bill or RMS products. I am just simply having minor fitment problems...that is all, I have ordered many parts from Bill, and his customer service and his products are top notch.

Has any one else had somewhat of the same problem? Or am I an idiot?

[70 Dustpan]

I ran in to the same thing on my 67 Valiant. Same arms and same wheels. I'm using 1/2" billet spacers and longer wheel studs. My will only touch with the suspension fully extended and with the wheel turned all the way. I can't see this really ever happening when driving. For the two to be at the same time so I figure that it shouldn't be any problem.

[Bill_Reilly]

1/2" spacer. Is the alignment correct? The spacer is needed for those wheels, but they my be hitting more than typical if the car isn't lined up yet.  In the pic, it looks like the strut rods are a bit longer than they should be. Stock length is with 1/4" of threads sticking out of the jam nut.

[bOb shingler]

wow dude, you have your hotrod jack up and the suspention hanging down and at full lock. i reckon while your driving this would ever happen and if it does you have other more pressing problems to turn your attention to. also if it bothers you then consider welding a stop nut on the steering lock stop so it doesn't turn so much. i had to do this on my hotrod and you never even notice it.

[qkcuda]

1/2" spacer. Is the alignment correct? The spacer is needed for those wheels, but they my be hitting more than typical if the car isn't lined up yet.  In the pic, it looks like the strut rods are a bit longer than they should be. Stock length is with 1/4" of threads sticking out of the jam nut.

That's good to know Bill.  When I put mine on I tried to measure from the old ones and had a lot more threads showing.  (see pic)  When I got it aligned the tech shortened them up quite a bit to get the caster in line.  I was afraid he went too far, and I might be binding the LCA's, but I'm sure I still have at least 1/4 inch showing.  I'll double check when I get home, but I feel better already.

[mopardude318]

Well, I'm using a 3/8" spacer, and don't think I wanna use a thicker one...And Bill, in the instructions for the strut rods, it says to thread rod onto bearing end approx. 3/4". And thats what I thought it should be, I have 3/4" of thread from the rod end and jam nut... I moved the suspension through its full travel of movement and it doesn't bind,  if I have it any tighter, or looser, it will bind on the lower control arm...

wow dude, you have your hotrod jack up and the suspention hanging down and at full lock. i reckon while your driving this would ever happen and if it does you have other more pressing problems to turn your attention to. also if it bothers you then consider welding a stop nut on the steering lock stop so it doesn't turn so much. i had to do this on my hotrod and you never even notice it.

Bob, I HAD the suspension sitting on the ground, and when I turned the wheel, the rim hits the UCA, not allowing me to reach full lock...So, I'm not going to weld a stop nut on the lower control arms. That is not an engineering option...

[Bill_Reilly]

With 3/4" of threads inside the tube, you'll have about 6 thread sticking out of the nut, or about 3/8".   But thats merely a sidenote, and will only make a tiny difference in this problem.  The big point is, when the car is on the ground, how much is the suspension compressed, and at that point, is the camber set to approx. zero? If the wheel is leaning in at the top, or if the suspension ride height is near the top of it's travel when camber is set, it will cause this problem with the stang wheels, which have too much backspace with the stock suspension and brakes.
  When you have the car on the ground, measure from the floor, up to the bottom of the k frame in the middle. You should be around 5-6"....

[mopardude318]

Strut rods are set to the same length as the factory ones were. Not a whole lot of room for adjustment. At ride height, I adjusted 1" from the LCA bump stop to the frame.






Here it is at ride height:





I have 7" from the ground to the bottom/middle of the k frame. Any lower I think I'll be too low, and I won't have any tension on the torsion bars...


Now with the wheels turned at ride height, it hits the UCA.

[Dan-o]

I have 9" from the ground to the bottom/middle of the k frame. Any lower I think I'll be too low...

, I can't get most full sized jacks under my k frame.  9 inches is A LOT.

[mopardude318]

I have 7" from the ground to the bottom/middle of the k frame. Any lower I think I'll be too low...

, I can't get most full sized jacks under my k frame.  9 inches is A LOT.

Well, now I got 7"...

[mopardude318]

Well, I also have 1.0" torsion bars from just suspension...if that makes any difference..

[golferjohn]

This is my first glimpse of your ride...very cool, the color (colour) is perfect...nicely done, Dude

[mopardude318]

This is my first glimpse of your ride...very cool, the color (colour) is perfect...nicely done, Dude

Thanks. But it'd be nicely done if I can get everything to work. 

[golferjohn]

I hear ya...when I went to replace some dash lights, I broke my bezel...back down to Shannon @ Red Line Gauges...it's been 2 weeks already, no dash 

[mopardude318]

yea, dash work sucks... But anyways, I'm thinking that I have everything right, and that the UCA are a little too wide...They are made for a coil over to go through them. If I try one that's narrower, I don' think Ill have a problem...

[jamesdart]

yeah mopardude, i think you are on the right track. i dont use a wheel spacer on my duster and my bullit rims dont rub my factory uca. too bad as i have bills arms waiting to go on the car. i just checked my k frame to the ground, its 7" off the ground, your car looks much higher than mine for some reason.

[Bill_Reilly]

Holy four wheel drive batman.  You can put different a-arms on and it'll clear the wheels, but that will only hide the real issues until you try to drive it. Aside from the wheel clearance, To make effective use of any of these pieces, ya gotta get the ride height down lower into a more usable range. 1" bars are way too big for a half-aluminum smallblock.  With a ride height that high, geometry sucks. It will still wander all over the place, and since those bars are totally unwound at ride height, the ride quality will be miserable. Thats assuming it can even be lined up properly.  Get it down another inch or two, and then check camber - you still havent mentioned where the camber is....

[mopardude318]

Well, I lowered my ride height, and now the frame is just right on the LCA bump stop...I cant lower it any more, as you can see because the adjuster will almost be all the way backed out...causing no preload at all on the T-bars. Also, I don't have an accurate way to check camber. the car is on the driveway, which is uneven and sloped. I dont have a camber gauge, so what would be the best way to measure camber, use a level or straight edge?




Now my ride height is a touch lower at 6 1/2", if you were to measure from the front of the K-frame:


and measuring from the rear , i have 5 1/2" from the ground:


and heres the other side:



does it still look too high from this perspective?

[Jim_Lusk]

That's a good height. If you have problems with bottoming on the LCA bumpers raise it a little (or cut the bumpers in half). You can get away with a lower ride height with the 1" t-bars compared to smaller bars. We also removed the LCA bumpers on my son's Barracuda so that we could set it lower. He's got 1.14 torsion bars. (he's also got an iron headed big block).

It is futile to measure any alignment angle on a non-level surface. When done you will want about 1/2 degree negative camber and 3-4 degrees positive caster with about 1/8-3/16" toe in.

[mopardude318]

Ok...At that ride height though, it seems that it is a bit mushy now, and that I need more load on the T-bars, is all... than it was with an inch over the LCA bumper..

[Jim_Lusk]

As long as the car is not sitting on the LCA bumpers you have as much twist in the bars as you are going to have. Tightening the adjuster bolt will only move the LCA away from the frame, it will NOT add or take away twist in the bar.

[Dan-o]

and remember, the tapered LCA stops are designed to act as part of the suspension system, as long as you're 1/4" away, you're golden.  Have someone sit on the fender, if it just touches, you're on.

[mopardude318]

As long as the car is not sitting on the LCA bumpers you have as much twist in the bars as you are going to have. Tightening the adjuster bolt will only move the LCA away from the frame, it will NOT add or take away twist in the bar.

Ok. makes sense...I'm gonna try to get my camber straight now...

[jamesdart]

so did lowering it help clearance at all? i agree as long as you have some kind of load on the adjuster it shouldnt matter if its 5 or 20 threads, should still be the same load.

[mopardude318]

so did lowering it help clearance at all? i agree as long as you have some kind of load on the adjuster it shouldnt matter if its 5 or 20 threads, should still be the same load.

no, lowering it still did not fix my clearance issue...

[mopardude318]

OK, my suspension has settled a little bit, and I measured 5" from the k-frame to the ground. It's right on the LCA bump stops, so what I'll do is just cut them down to 3/8" or 1/2". The rim still hits the UCA's though...

[Jim_Lusk]

You need to align it to be sure of the fitment, but it may still require more spacer as the rim is not really designed for this suspension.

[rokketride]

You need to align it to be sure of the fitment, but it may still require more spacer as the rim is not really designed for this suspension.

That's really the bottom line here, having the wrong backspacing makes for a multitude of problems.

[blackbetty]

I may be wrong but I think the factory bullets are 17x7 so if u have 17x8 you would need a bigger wheel spacer. They also change the back spacing on the new body style mustangs (retro ones) so if the wheels are for the new car the wheel spacer would need to be larger.

[Bill_Reilly]

5" is a real nice height from a behavior perspective.   with alignment and the clearance problem, the only thing to check is camber - as long as the car is level side to side, you hold a small level or angle finder, vertically on the edge of the rim to be sure the tire is about straight up and down - that will be the only angle that affects the rim hitting the arm.

If that angle is ok and it hits that bad, I'm at a loss to know why - if its the rim with 5.72" of backspace, lots of guys are running them with 3/8" wheel spacers, so I'm puzzled as to why they would hit so hard in this car. Stranger things have happened though, so I'm puzzled, but not shocked...