Control Arm Dilemna

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John Brennan
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Control Arm Dilemna

Post by John Brennan » Thu Nov 17, 2005 9:24 pm

Well, BAT sent me a set of Scorpio TCA's instead of XR4Ti ones, which I discovered upon trying to fit the new Powerflex bushings into the inner joint and discovering them to be too small. Further examination reveals that another difference between the two arms is that the Scorpio arm, besides having a slightly more robust appearance, is about 1/4" shorter between the outer TCA and the ball joint. This will reduce track accordingly, and slightly decrease negative camber as well.

Of course, BAT are out of stock until "after Thanksgiving at least," and therefore I have a couple of choices:

1) Replace the old arms, but with the new bushings, and wait for BAT to receive a shipment.

2) Use the Scorpio arms with Scorpio inner bushings.

3) Get XR4 arms from someone else (and pay lots more money, wait for shipping, etc.).

Peter at BAT was under the impression that the two arms were not interchangeable, that there may be problems with geometry, etc. Losing a little negative camber now could be made up for by slightly lowering the front end later, however. I am unsure as to any other deleterious effects of using Scorpio arms, e.g., clearance issues with wider tires on full-turn deflection.

Is anyone using Scorpio arms, or have personal experience with the subject? I need to get this thing back on the road...
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GeneticRehab
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Post by GeneticRehab » Thu Nov 17, 2005 10:32 pm

Hey JB. I can get mooge greesable control arms for the xr. do you want me to price them and get you a part number?
Jason Liss
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John Brennan
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Post by John Brennan » Thu Nov 17, 2005 11:03 pm

Sure-- I'm not familiar with them. Are you saying that being greaseable, that the ball joints are serviceable? TIA.
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DPDISXR4Ti
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Post by DPDISXR4Ti » Fri Nov 18, 2005 12:58 am

I doubt if the Moog's have replaceable joints, but with a zerk on them they'll be greaseable and thus should have a longer service life (if greased, of course).

What's really odd is that this evening (about the time John was typing his message), I was out in the garage with a XR and Scorpio control arm in each hand, comparing the two. :shock: I was considering how/if a Scorpio control arm could be used on a XR :shock: :shock: I just checked - nope, not a full moon tonight...

Any way, I didn't come up with a definitive answer, but here's a couple things to keep in mind...
1) Ball joint and inner through-bolt are larger on the Scorpio
2) The Scorpio anti-sway bar has a slightly larger spread to it

So here's what I'm thinking might work:
Scorpio control arm
Scorpio anti-sway bar (same size as Cossie bar, I believe)
XR hub modified for larger ball joint stud
XR subframe hole enlarged for larger Scorpio bolt (12mm?)

I suspect this combo will give you a wider track and more negative camber, as the total length of the Scorpio arm is greater than the XR. I'm not sure about caster.

Back to you Johnny... :wink:

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Post by John Brennan » Fri Nov 18, 2005 2:22 am

Thanks, Ed. Ed MacMahon, ladies and gentlemen... thank you!

Well, Hell's Bells-- looks like I'll be slapping the old arms back on for the time being... need the car back.

As Patton once said, "I hate paying for the same real estate twice." :x
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Post by Greenturbo » Fri Nov 18, 2005 4:58 am

i got mine from BAT and some pollys, they work well
and the despite what he said abut the shipment taking a while.. they came promptly.. and they worked well

and you cant beat the price..

on a side not i remeber hthe guys at mc2 racing said that there was no need for alarger swaybar in the front.
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Post by Grayson » Fri Nov 18, 2005 10:08 am

Replaceable ball joints may not be "all that". After spending some intimate time with my F350 replacing the right front upper and lower ball joints, I'm not all that interested in replacing the ball joints on an XR anymore. Ok, I'm saying this mere hours after the experience from hell, so perhaps I'm a bit biased right now. Anyway, replacing press-fit ball joints is not a job you do without a press. A good press.

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Post by AnHonestCitizen » Fri Nov 18, 2005 10:15 am

Here is a photo of three TCAs side-by-side:
Image

Left to right: Scorpio, Sierra Sapphire, Merkur XR4Ti.

IMO, the Scorpio TCA is too different to use on the XR4Ti. I think it would mees up the geometry too much. Another thing is that the Scorpio ARB seems to be longer than the XR ARB, on top of being wider. I think the extra length would really mess up the geometry, if true. (I eyeballed the the two ARBs side-by-side one day.)

Another factoid: an easier way to bolt the Scorpio arm into the XR sub-frame would be to use Scorpio Powerflex poly bushings but substitute the Scorpio metal sleeves with ones made for the XR4Ti. The OD and length on all Powerflex metal sleeves are the same. Only the ID is different (i.e. larger) on the sleeves provided with the Scorpio bushings.

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Post by John Brennan » Fri Nov 18, 2005 2:33 pm

OK, well this adds to the mystery, because the ones I got from BAT look like the Sierra/Sapphire ones; maybe they sent them to the U.S. by mistake, and then those got sent to me. Brad's comment about Scorpio arms being longer than XR4Ti ones raised my eyebrows as well, since these I have are definitely shorter-- by about 1/4"-- than the old arms off the car... and the difference is all outboard of the outer TCA bushing. Also, the 10mm bolts for the inner TCA's seem to fit in these arms' bushing also-- not like they're 12mm. If the S/S inners are 10mm, then I know for sure what I've got. :?

Edit: Just got off the phone with Eric at BAT, who very sincerely apologized for the error in shipment, and will be sending me some personally-inspected arms as soon as they come in. So for now, I'll put the old ones back in, send him back these, and drive carefully!
Last edited by John Brennan on Fri Nov 18, 2005 2:51 pm, edited 1 time in total.
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Post by AnHonestCitizen » Fri Nov 18, 2005 2:42 pm

It is impossible to see in the photo I posted, but the ball joints in the Sapphire arms are made for use with pinch bolts, not castle nuts and cotter pins like the original Merkur Scorpio and XR4Ti arms, or nylocks like the replacement arms that are the norm nowadays. The Sapphire arms take 12mm bolts, too. I don't know what ya got there John. Is the total length shorter than the original arms?

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Post by John Brennan » Fri Nov 18, 2005 2:56 pm

Me, neither. The ball joint nuts are castle nuts, and yes, they are about 1/4" shorter...?!
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Post by DPDISXR4Ti » Fri Nov 18, 2005 5:41 pm

Okay, I decided I better be 100% sure of what I said, and this certainly verifies that the Scorpio arm is longer.
Most all of the greater length appears to be made up from the inner mount to anti-sway fitting. Add "Scorpio inner
tie-rods" to my list of required items above, although as suggested, the geometry might be an issue. Somebody
should compare the XR vs. Scorpio shock tower distance.

Image

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Post by John Brennan » Fri Nov 18, 2005 8:21 pm

Right, and the other picture makes it quite clear that the Scorp arms are longer-- so it definitely wasn't those I got. I sent them back to BAT, but they were a little shorter, and again, that seemed to be specifically in the outer-to-ball-joint "neck" area. That and the larger inner bushing size were the only differences-- even the bolt bores were the same, not like the readily observable difference in the above photo.
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Post by wilky » Fri Nov 18, 2005 9:04 pm

Slightly off topic but I keep seeing adjustable length Sierra LCA's on Ebay UK - anyone know if they will fit my XR (the one lowered 50mm and with the serious case of negative camber).

Cheers

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Post by DPDISXR4Ti » Fri Nov 18, 2005 9:10 pm

wilky wrote:Slightly off topic but I keep seeing adjustable length Sierra LCA's on Ebay UK - anyone know
if they will fit my XR (the one lowered 50mm and with the serious case of negative camber).
As long as they're for a Mk I Sierra ('83 - '86ish), you'll be fine. That said David, most of the ones I have seen are
designed more with racing in mind, and only allow for the wheels to go further negative. If however they can
be setup to be shorter than stock, you'll get the camber more positive as you desire.

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