I'm trying to figure out the correct traction bar for my 67 L30/M20 (mine was removed). On CRG it states that around April or so they started using the square traction bar instead the round. Mine was built April of 67 so it's right in that transition period. The bracket on my twelve bolt has two holes which resembles the bracket shown in the assembly manual under L78 for the square bar as opposed to the one hole bracket shown under L48 marked cancelled.

Anyone have any info to steer me in the right direction?

Also, on the under floor bracket there is one bolt that goes into the frame rail. The assembly manual says that there is an existing nut there....not one mine! :( There isn't an open slot under it like for the front leaf clip nuts and the hole is round (bigger than 3/8 but less than 1/2). What kind of clip nut would fit into a round hole like that? :confused:

You could put a nut-sert in the hole. It's a large rivet with threads in the center.

David

Paul,
Are you sure your car had a radius rod? How do you know it was taken off?
Daniel

I agree with Dan. If there isn't a nutsert in the frame rail, then there wasn't a bar installed. Besides, I bet you are probably missing the floor plate also under the rear seat. Are there 2 studs showing under the car close to the frame rail?

Scot

Aw c'mon guys don't you trust me?!?! :D

Yes I have the plate with the two bolts sticking through the floor and the front bracket for the radius rod (just missing the "nut-sert" for the bolt to the frame rail) and the welded on bracket on the passenger side tube of the 12 bolt.

Here is the best pic that I could take of it (the weld on bracket got tweaked somehow during its rough life) without the front bracket bolted on:

http://www.stratagaz.com/67L30M20/L30M20-MissingTractionBar02.jpg

The build date for my car is 04C, engine stamp is T0410MK, tranny stamp is R7C23 and axle tube stamp is QJ0412. Pics of those stamps and more can be seen at:

http://www.stratagaz.com/67L30M20/1967L30M20Convertible.htm


So, anyway is there a difference between the round radius rod and square radius rod axle tube brackets? I'm pretty sure that mine is the bracket for the square rod according to the assembly manual pics anyway, just trying to verify.

Paul,
CRG has seen lots of other cars that just have the floor studs and a bracket on the axle. Even my 12A LOS car has the studs on the floor. One of the reasons that I asked if the car ever had the rod is your axle ratio. I have seen data on other L30/M20 cars that had the rod, but most have a 3.55 ratio not a 3.07. Unless you can find good evidence that your car had the rod, I would say that it was never there.

Really!?!?! Well that's a new twist. So our cars came from the factory with everything needed to install the radius rod, just without the rod itself! :confused:

Man, glad you guys are out there digging up all of that data, because I automatically assumed having all of the brackets that it also came with the rod.

It's been a while, but when I bought the car I'm pretty sure that the owner said that it had a radius rod at one time, but I don't know if he was just talking or not. Hmmmm, more to ponder. I suppose the nut-sert would be the only indication one way or the other and mine is not there. I'm not sure if those easily broke off or if it really was never there meaning no radius rod. :confused:


So, Daniel was pretty much every 67 12 bolt installed with the weld on bracket or is that hit or miss too? You would think that especially later production that they would have the bracket as anywhere a 12 bolt was going was a performance application where wheel hop could occur. And what about the floor plate...how did they determine which car got that I wonder?

[ 05-17-2004, 08:26 AM: Message edited by: paulm ]

Paul,
I would look real close at the studs on the floor for signs that there were ever nuts on them and also at the axle bracket to see if there was a bolt through it. I am not saying that you are not right, but I would make sure that there are signs that there was one, before I go and spend the money to put one on it.

So, Daniel was pretty much every 67 12 bolt installed with the weld on bracket or is that hit or miss too? You would think that especially later production that they would have the bracket as anywhere a 12 bolt was going was a performance application where wheel hop could occur. And what about the floor plate...how did they determine which car got that I wonder? The early 12 bolts did not have the bracket. I am still looking at this, but I believe that all of the Q 12 bolt axles had the bracket. We have data on a lot of cars that just have the bracket and no rod. A lot of this just needs more research, and it gets tuffer when cars that never had rods are latter modified, putting them on.

The floor plate stud threads were chewed up as I had to run a thread dye over them...The axle tube bracket was bent, so it's hard to tell if there was anything there. You also have to take into consideration that I sand blasted the underbody of the car, 12 bolt, etc. So any evidence may have been altered by the pressurized sand.


Oh, Daniel I would take you input as much more accurate based on all of the cars that you guys log data for than what a guy trying to sell a car says. graemlins/thumbsup.gif

Based on the info that you provided Daniel I am going to have to assume that mine did not have the radius rod. It is possible that it may have had it, but there is not enough evidence to prove that it did. The only things that mine did in fact have are the axle tube bracket, in floor plate and front rodius rod mounting bracket, missing the frame rail nut-sert, rear rod to axle tube bracket bracket and the radius rod itself.

I may add one merely for the "cool factor" but in your database it should probably recorded as most likey did not have the radius rod.


Thanks for the info Daniel!!

Anytime Paul. Glad to help. smile.gif

My 67 FB, that my mom bought new, has the brackets and studs, but never had the radius rod; round or square.

All of the firebirds that I've seen (I guess not that many 67's) had two rods (or at least brackets for two rods), one on each side. Is that how yours was too? I always thought of it as Pontiac doing the "one up" thing to Chevy. :D

My 67 RS/SS 350 (build 09C) did not originally come with the rod either. But, it was added later in January 67 by the dealership. Rear end code PC0901G2. I have seen that in some websites that PC is actually for SS350 4 speed cars only. I beg to differ this is not the case. Mine is actually a PC plain and clear. I hope that CRG considers this data to be cloudy as well.

Scot

Yes, the axle tubes,L&R,have the brackets welded in place. This is an open 10 bolt rear end with a 2 series gear. Go figure?

Funny about the 10 bolts....Didn't all of the Firebirds have 10 bolts? I don't remember ever seeing or hearing of a firebird with a 12 bolt.

PC is actually for SS350 4 speed cars only The PC axle was used on more cars then this one application. Scot, CRG knows that your radius rod was added at some point because your car is way to early for it to be from the factory.

To add to the confusion, there were some plain Camaros with 12 bolt rear factory installed. I saw one 2 bbl, PG, no option 67 Camaro with original 12 bolt. The bracket was on the rear axle tube but no other traction arm parts.

How do you know that the 12 bolt was original? Was there a build sheet or something?

Joe is correct. A few LF7 and L6 cars got 12 bolt axles. Most that did though were 2.73 posi.