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beater72

Rear sway bar

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Hello!I'm looking for a pic if the rear sway bar mounted on the car.. need the pic from the rear of the car please. Thanks in advance!

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So the stock one isn't attached to the diff at all? It is only connected to the lower control arms?

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I added a rear anti-sway bar way back in 1972. I either used the existing 4 or perhaps drilled two additional holes and mounted it ONLY to the A arm from one side (with short bolts) of each A arm, since they were not boxed. After 20+ years my nephew boxed them and I now run longer bolts through both sides of each A arm. Having it the first way never did any damage, for over 95,000 miles anyway. I threw on a Big Block 1-1/8" ft bar also about 27 years ago. Good times!

Bruce

 

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Kris, as you probably know, the only way to get an original factory rear sway bar on a first gen Monte was to order RPO F41 Performance Suspension, the RPO Z20 SS package ('70, '71) or the RPO Z03 Custom package ('72).  RPO F41 included a larger 1.125" diameter sway bar in front and a smaller .875" diameter sway bar in the rear connected to boxed lower control arms.

 

If you want to add a rear sway bar of the factory style, you have several choices.  The Parts Place Inc has six different kits available.  If you already have boxed control arms (doubtful), you can order just the rear sway bar (including attachment hardware) in either factory equivalent 7/8" (.875") diameter or 1" diameter for $99 (pn SU12842A and SU12843A, respectively).  Or, if you need boxed control arms and a sway bar you can order one of four complete kits and choose between the same two diameter sway bars and also choose either rubber or poly bushings in the control arms (see pn SU1178A, SU2268M, SU5335M and SU5337M).

 

When I installed a factory-style rear sway bar on my '70 402/4-speed, I bought a very nice pair of factory boxed control arms from another member (even had new rubber bushings installed) and went with a Hellwig 1" diameter bar instead of the factory 7/8" bar.  You can also buy conversion kits to "box" your current lower control arms from Summit (pn OPG-RCAI001 ) for $46.

 

As you probably also know, there are literally dozens of front and rear sway bar manufacturers and models to choose from.  Most of them offer designs superior to the original factory style if you are more interested in performance than originality.  At least some of the rear sway bar designs require connection to the axle, if that is what you were wondering about, but the factory style does not.  More photos of the factory style and control arm connections below.

 

post-567-0-64978600-1484085429_thumb.jpgpost-567-0-07994600-1484085447_thumb.jpg

 

 

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I'm guessing more for a somewhat stock appearance as I'm going restomod leaning heavily toward stock.I'm not building to car for road raving or anything. Truth be told to me that's the charm of these old cars is how they handle..thanks very much for the input and help up to date!

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Hellwig sway bars are not only less expensive but offer much more torsional rigidity.  Rather than mounting solely to the lower control arms (due to twisting logically when one side is pushes down the opposite is lifting).  Not optimal when looking to better handling.  The Hellwig bars are hollow(lighter), less expensive and the center of bar mounts on either side of the center differential and then rather than being mounted to lowers arms on each side ..... they come with links to attach directly to an unused mounting hole in the frame.  If you want a picture shoot me a PM with your email.  I have some great frame off shots of install if needed.

 

Dan 

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Not to comindire the thread but I also want to add a rear sway bar and replace all bushings on the front one. Do I need to do something special or have to completely change the trailing arms in the rear to add one? 

Would you all recommend replacing the front one also for a thicker one or replacing the rubber with polyurethane bushings be enough?

Thanks,

Mike

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Mike, if you intend to install a stock-style rear sway bar, you should use "boxed" rear lower control arms.  You can replace your current rear control arms with a used or new pair of "boxed" arms (as I did) or you can buy a kit and "box" your current control arms by welding the kit pieces into the center of the control arm.  That modification greatly stiffens the control arms so the sway bar does not twist or deform them when it does its job. Check out the Part Place Inc, identify your vehicle and select the Suspension category and use "Control Arms - Rear Lower" as keywords.  You will find lots of options from complete kits inducing the bar, boxed control arms and hardware to any of the individual components.

 

I have rebuilt the front suspension of both my '70 402 and my '70 SS with stock replacement parts.  The SS uses a 1 1/8" diameter front sway bar (the non-SS bar is 15/16" diameter).  Since RPO F41 sport suspension option (standard on the SS) also uses the 1 1/8 " dia bar, you could easily upgrade to that size but remember that you will need to get new rubber bushing that are specifically made for a 1 1/8" bar and they are not so easy to find. I did not upgrade the front bar when I added a rear sway bar to my non SS car but I don't drive aggressively enough to tell the difference, either. 

 

I went with all natural rubber bushings on both front end rebuild projects (and the boxed rear arms) simply because I have heard too many complaints about the poly bushings squeaking and/or giving a bit harsher (firmer control) handling.  I don't want or need race car performance so I opted for the milder solution.  I'm sure you will get several opinions on this and you can do whatever feels best to you.  Good luck.

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Regarding the bushings.  I agree with Dennis on the squeaking Poly bushings. The polly bushings will last and last which is a good thing but if they squeak after awhile you really don't need them to last a long time.   I stayed original rubber bushings.  After all the original rubber bushings on my car lasted 31 years and when I replaced them, they still looked very nice so if the like original bushings lasted 30 years and the new ones last that long it will be someone elses problem, not mine.

rob

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Thanks Dennis & Rob.....Good points rubber will be what I will replace the bushings with. She sags more than I would like so I figure since I will be replacing the springs (rear first) I should go ahead and the the boxed trailing arms.... do you need a press or any special tools to swap out the trialing arms? and you just replace the lowers uppers stay original?

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Mike, it's been a couple of years since I installed the boxed control arms and sway bar on my '70 but I think I can remember enough to answer your questions accurately.  

 

First, you do not need to touch the upper control arms to replace the lower arms - I didn't. However, if you suspect the bushings are bad in the upper arms, this would be a good time to replace them.  You will at least double the time and effort you spend on this project if you do because you will need to remove and replace those bushings or replace the entire upper control arm assemblies.

 

Second, the bolt and nut that secure the lower control arm to the frame are torqued very tightly (70-90 ft lbs) so you will likely need an air impact tool or a long breaker bar to get them loose.  To break the nut loose, you must hold the bolt head that's inside the frame.  You can only reach the bolt head through an access hole in the frame using a socket drive extension.  If you don't have an air impact wrench, Harbor Freight sells a 25" long 1/2" drive breaker bar that will get the job done nicely,

 

Third, when you install the boxed replacement arm, you must torque that front bolt WITH THE CONTROL ARM IN A SPECIFIC POSITION (NOT with the rear axle hanging down).  This is less of a problem if you are lifting the car using a lift where the tires are on the lift, however, if you are using a frame lift or a pair of jack stands under the frame, you MUST lift the rear axle (I put the floor jack under the center of the differential) to the correct BUSHING LOCKUP DIMENSION which is 5" between the top of the axle housing and the bottom of the frame arch directly above it (see illustration in the bottom right corner of the Assembly Manual page photo below). Now you can tighten and torque those front bolts (70-90 ft lbs).  All of this is prescribed in the Chassis Service Manual and is necessary so the rubber bushings in the control arm will not be abnormally twisted or damaged during normal suspension travel.  If you torque those bolts with the rear axle hanging down, the rubber bushings will be severely twisted and probably damaged during normal suspension travel.  BTW, my theory on why poly bushing often squeak is because they don't twist like rubber bushing but instead slip against metal as the suspension moves up and down.  You can have either the squeaking or impaired suspension travel, possibly both ... some choice!

 

post-567-0-12020300-1486245133_thumb.jpg

 

Fourth, when you bolt the sway bar onto the boxed control arms, you should use whichever supplied shims will ensure a good snug fit between the bar ends and the arm so your suspension geometry is not affected when you torque the two bolts (35-55 ft lbs) that hold it together on each side.  See Assembly Manual photo below for RPO F41 installation.

 

post-567-0-84550600-1486245142_thumb.jpg

 

Depending on which sway bar kit you buy, it may come with some specific instructions.  Mine certainly didn't so I consulted the Chassis Service Manual and was glad I did.  BTW, if you ever remove/re-install or replace the front lower control arms, the same bushing lockup considerations apply to those bolts.

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:dt

 

if you use the poly bushings, you do not need to worry about the procedure above, poly bushings inner sleeve turn inside the bushing, that's why if not properly lubricated they will squeak, and why they end up squeaking after some time

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The after market UMI control arms have grease Zerks.....no more annoying squeak. If I was going to go through all the work to remove the originals and box them in then change bushings and put them back on, I personally would just buy after markets. They are not that expensive. UMI performance lower control arms were less tha $250. I am very happy with them.

http://www.ebay.com/itm/UMI-Performance-64-72-GM-A-Body-Boxed-Lower-Control-Arms-Chevelle-GTO-Lemans-BLK-/201507850067?hash=item2eeacdc753:g:u6gAAOSw5dNWn~wO&vxp=mtr

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Those UMI units are real nice Rock.. !!They are the same as stock price wise @ $209 need to think about that....

 

MCfan...truly nice description of the process, I'm fairly good with mechanics and do have an air Impact and compressor so will definitely tackle this in the garage. Going to replace the springs and will probably replace the upper bushings too while at it and get that sway bar on there .... should make a big difference from the saggy springs set up I have now... And THANKS for the drawings !!!!!  sweet !!

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