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What size bolts are required to bolt a sway bar to BMR rear lower control arms? Haven't been able to find by Googling and would prefer to not have to do hardware store trial and error.
 

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Morning. I can't say for sure what the bolt size is but I would make a guess it's the stock size. I C & Peed this as a reference.
Based on FSM, 1994-1996 rear sway bar bolt size:

M10 X 1.5 X 110MM (Roughly 4.3 inch long), 15MM socket size for the hex-head.

The nut is lock type.
Here's the thread- https://www.impalassforum.com/vBulletin/17-suspension/844689-rear-sway-bar-grade-8-bolt-size-2.html

If nothing else take the bar with you to the store, That way you're not having to trial and error it. That is if it's not already installed.
We can flesh this out. :wink2: I had another thought. Do you have tap and die sets? SAE & Metric. There are gages in it to determine threads in them.\ or use a tap to try it out.

Mark: Snowman-33
 

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What size bolts are required to bolt a sway bar to BMR rear lower control arms? Haven't been able to find by Googling and would prefer to not have to do hardware store trial and error.
May be worth a call to BMR to see what they would recommend.

Having aftermarket Lower arms myself and mounting a rear Sway Bar to these is different than Stock and uses different HW. My Boxed arms just had a Thru Bolt passage way and I just used a Long Grade 8/10 Bolt with a Nylon Lock nut on the other end. Most likely the BMR Arms are the same and you just need to make sure the bolt is not too fat to fit thru and too long to interfere with anything.

Otherwise, it's just a pretty straighforward clamp on deal. Just measure the diameter of the Arm thru hole to determine the largest bolt you can use. Then just measure the distance thru the bar and Arm, add whatever for enough thread to account for a Nut and possible a couple of washers and you should be GTG. Really not a complicated process but being different from a stock setup, you gotta be willing to make some trips to assure you get the right parts. Minimizing your trips can be helped with good measurements. Best bet may be a Fastenal Store to get what you want in the correct Hardness.
 

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Suggestions above are about the best - if you don't already have several decade's collection of hundreds laying around ::senior chuckles:: Seriously just a note that with long enough bolts it becomes smarter to install them before connecting both ends of the arm. And depending on how close the tolerance on your bar, find something to back up the hole with a think iron washer or drill up some barstock. We don't want those nuts pulling through.
 

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Suggestions above are about the best - if you don't already have several decade's collection of hundreds laying around ::senior chuckles:: Seriously just a note that with long enough bolts it becomes smarter to install them before connecting both ends of the arm. And depending on how close the tolerance on your bar, find something to back up the hole with a think iron washer or drill up some barstock. We don't want those nuts pulling through.
Bob, Good thoughts here. I have some square bars for my car and I will remember to do what you suggested. Now back to what Flesh asked. I looked and the BMR bars are round and I believe there are nuts welded to the top. The pictured didn't show that clearly. This is why I think they would use the stock size. BMR doesn't list bolt sets for sway bar mounting. And yes, my nuts and bolts are plentiful too.

Mark: Snowman-33
 

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Simplest way is to just use some old head bolts.
Use the longer ones, they are 7/16" dia coarse thread.

Nab
 

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Discussion Starter #7
I contacted BMR and a guy named TC quoted me $16 for the nuts and bolts. SOLD, I said.

They just arrived today.
 

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I measured mine. It is a hardened 7/16" bolt 4" long, with a nylock nut. I added thick washers to the top and bottom. I have the thick HO sway bar.
 
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