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Detritus Maximus
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Discussion Starter · #1 ·
So, I have a little problem installing my new Addco rear sway bar (bet you would have never guessed that from the thread title, huh? Ah, my devious ways......).

The problem I am having is that if I install it one way, with the 'pointy' middle section of the bar 'up', it hits the body (above the differential, next to the driveshaft/trans tunnel opening) and the ends hang down to where they are about level with the tops of the spring seats on the rear end.

If I turn it over, with the pointy middle section 'down', the point hits the differential and the bar prevents the rear end from moving any further towards its normal position.


Any thoughts from anyone that may have dealt with this?

I am suspecting they may sent me the wrong bar. Manta, maybe?

Or am I missing something so completely obvious that I will have to kill myself to end the embarrassment? (I don't have a problem with that, since it would mean I could get it installed before the 'killing'.....:D )
 

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Detritus Maximus
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Discussion Starter · #3 ·
I looked thru Jimsky's pics before, but none show the center pointed section of the bar.

This pic shows the end:




If I were to get the end that high, the point on the center section of the bar would go through the floor pan by about an inch.

If you lay the bar on something flat (floor, table, really huge book, etc....) with the ends laying flat, the pointed section (kind of triangular shape in the center of the bar to clear the diff/torque tube) is comparatively at about a 50 degree angle from the plane fromed by the rest of the bar and the ends (by 'ends' I mean the end of the bar where the 'end links' attach, no the end links themselves).
 

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Any update on this Opelbits?
Have you spoken to the addco supplier to check the part number and make sure it is the right one? I've had the same problem with my rear addco bar, I was able to get it in but it only has about 1/2 inch of clearance. I haven't had a chance to drive the car yet to see if it will hit during normal driving. I thought about bending the floor plate up some to allow more clearance if necessary.
 

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boomerang opeler
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i may be wrong but a sway bar twists across the body when it works as apposed to vertical action (between axel link and pivot bush)
so a 1/2" clear above the bar should be ok
jm2cw
 

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Detritus Maximus
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Discussion Starter · #6 ·
No update, yet. I went ahead and installed a new fuel pump (replaced very noisy Facet with which I was never really happy with a Carter rotary type) so I could drive the car. So the sway bar is back on the bench in my garage. I haven't talked to anyone at Addco, yet. The numbers on the box/invoice/etc. are correct. I figured I would ask here, where people wmay have direct experience with the GT application.

While the sway bar does twist, it is in relation to itself. One end will leverage the other with the bar twisting along the bars axis. However, the bar does rotate up and down with the up and down motion of the rear axle. The problem I have is that when the axle moves up, the pointed triangular section of the bar will hit the bottom of the car and act as a stop, preventing normal suspension travel.
 

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I finally got all the pieces today and got the head back together on my GT. The test drive went well and I never heard the rear sway bar hit so Baz is probably right that it is more a twisting motion than an up and down travel issue although there is vertical movement that follows the rear axle.
 

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Hey I'd be happy to shoot more photos of my installation if they'll help someone. Next time just shoot me a PM.

The top bow of the rear sway bar is close (1/2") but doesn't hit the body. I've never heard nor seen any evidence of interference. See photos below. If other photos/angles will help just ask.
 

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I've been watching this thread, and now I'm curious. Sway bars are an upcoming project for me. As the rearend travels vertically the relationship between the rear axle mounts and the body mounts have to change angles. This would cause a roll of the sway bar depending on spring load or unload. Load causing sway bar roll toward body and unload causing it to move toward the axle. What I mean is both wheels loading the springs, one wheel would only cause a twist. I'd be real curious what effect more rear weight had on this, full tank of gas vs empty or spare parts stuffed in spare tire area for example. My car is lowered so I have less room to play with back there. Anybody have any ideas on this or am I out there in left field again?
 

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I agree with Jimsky on this one. I just took my car out for a much more aggressive drive and the sway bar never touched the floor pan. What a difference it made to the handling! Very flat, no body roll in long high speed corners. I'm very happy with the performance gain vs the cost.
 

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Detritus Maximus
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Discussion Starter · #12 ·
Jimsky-

Thanks for the extra pics. In my car, if I move the center of the bar down for clearance between the floor and the diff, the bar ends are about even with the top of the spring seat (where it is folded over). If I remember right, this would put the lower mounting bolt for the end link at the very bottom of the spring seat which is a tough spot to drill a hole and insert a bolt.

If I am reading your pictures right, I think I may have too much angle when comparing the bar ends and the middle point.
 

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I guess I wasn't clear on what I was wondering about. Body roll won't effect any real change other than twist in the bar. What I was talking about was more of a big dip in the road, or more weight. Things that would effect the body to rear end dimensioning. I wonder if that Addco bar would even go into my car as the rear dimension would be shorter from body to spring cup than stock. For me it looks like I would be into the body or shortening the links. That's why I was wondering what happens when both springs are shorter, like the rear end was more loaded than normal.
 

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Nobody,
If you car is already lowered then I would recommend going with the OGTS rear sway bar. It appears to be bent differently from the ADDCO bar and "should" give you better clearance between the car and the bar, lessening the issue of "bottoming out" when the rear axle moves vertically.

This link has some good shots of the OGTS rear bar.
Swaybar installation
 

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Ya I know about the OGTS bar. With it you position the bar where it needs to be before you weld the mounts to the axle. For a lowered car it might be the only option. Any foreseeable problems with the front bar? If I'm gonna do it I usually go all or nothing. The front is so stiff with the OGTS spring I don't know what a sway bar will do. I know it will help lateral roll but I wonder now if it will pick up one side being so stiff. The tire sidewall is all the give there is in the front. If you jack from under the front corner it moves but not much.
 

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The addco front bar should fit as well as the OGTS bar since they both require the same amount of room to fit them in and there are no factory mounting postions as with the rear bar. Simply mount it to the lower control arms and then see where to drill the holes in the frame rails.

How much did you lower your car, I've been considering lowering mine at least an inch. I see that OGTS sells a 1" and a 2" lower spring, couldn't a spring shop "de-arch" an original spring and get the same effect or would it soften up the ride too much?
 

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I have the 2 inch front spring and you wouldn't believe the difference between it and stock. Stock out of the car is "U" shaped where the 2 inch has a slight arch to it. In the car the stock has a slight arch and the 2 inch still looks just like when I got it. If I jump up and put my weight on a fender you can see just the slightest of movement in the suspension and everything else is tire sidewall compression. I really like the way it looks and from what I have been able to tell it rides fine. On the oher hand after I installed it I made a mental note of all the speedbumps in town, in the GT I can't go there. I have like a 5 inch mound on one side of the back drive, I almost high centered it. I think the stock spring has too much spring to go that low. It would be hard to take that much out of it and still have anything left. It is funny to look at a stock GT now, they all look like 4 wheel drives to me.
 

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rear addco sway bar set up??

Probably another stupid questionbut better than mistakes. I have the addco sway bars too .I was under the impretion that all the hole were alrady there. It seems that the one by the spring carriage aren't there . How do I know for sure where to drill the hole.With the car up in the air & the wheels partly supported ,the suspention is partly suppressed wouldn't this change the spot to drill .Not sure if that makes sense!What I mean is if I install the bar with everything bolted down but the last 2 bolts by the springs do i just drill where they end up? . thanks for any & all input Eh
 

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Probably another stupid question but better than mistakes. I have the Addco sway bars too .I was under the impression that all the hole were already there. It seems that the one by the spring carriage aren't there . How do I know for sure where to drill the hole.With the car up in the air & the wheels partly supported ,the suspension is partly suppressed wouldn't this change the spot to drill .Not sure if that makes sense!What I mean is if I install the bar with everything bolted down but the last 2 bolts by the springs do i just drill where they end up? . thanks for any & all input Eh
North American GT's only had the holes in the body, and not the OEM attaching bracket welded to the differential as shown in the link in post #14 (OGTS bars are the same design as from the factory), nor the holes required for the Addco bars. The Addco bar requires holes be drilled in the spring buckets, as shown in the link in post #3. I installed Addco bars on my GT (well, in a historical sense, as it is in MANY pieces at present!) and the angle iron brackets are exactly as shown in that photo. IIRC, I drilled the holes with the car up on ramps at both ends so that the bar cleared the body, the end bolts with the rubber busings were as close to vertical as possible, and the holes in the buckets were positioned such that the bolts didn't interfere with the coil springs. Do you have the installation instructions from Addco?

I seem to recall that it was a tricky bit to get the bolts inside the buckets sticking out so that the nuts were on the outside, otherwise the bolt ends and nuts got in the way of the coils. Now that my differential is sitting in a corner of the garage, I can see how easy it would be to install the brackets with the differential dropped and the coils removed.

HTH
 

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North American GT's only had the holes in the body, and not the OEM attaching bracket welded to the differential as shown in the link in post #14 (OGTS bars are the same design as from the factory), nor the holes required for the Addco bars. The Addco bar requires holes be drilled in the spring buckets, as shown in the link in post #3. I installed Addco bars on my GT (well, in a historical sense, as it is in MANY pieces at present!) and the angle iron brackets are exactly as shown in that photo. IIRC, I drilled the holes with the car up on ramps at both ends so that the bar cleared the body, the end bolts with the rubber busings were as close to vertical as possible, and the holes in the buckets were positioned such that the bolts didn't interfere with the coil springs. Do you have the installation instructions from Addco?

I seem to recall that it was a tricky bit to get the bolts inside the buckets sticking out so that the nuts were on the outside, otherwise the bolt ends and nuts got in the way of the coils. Now that my differential is sitting in a corner of the garage, I can see how easy it would be to install the brackets with the differential dropped and the coils removed.

HTH
Thanks Keith. The instructions from Addco were very vague. The picture underneath wasn't even a GT. Guess maybe it fits other models too. Yes it looks tricky getting that bolt in. As well you're going to have to get in there somehow to hold it when tightening things up. Needle nose vise grips probably. Would of been so easy & useful to have a template for the exact location of the hole in the spring bucket.need to get it right on or the bar will rub on the underside.
 
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