BMR Torque arm issues.......

[speedyWS6]

Hey Guys,

Stu, who owns my last TA has gotten far more into the suspension mods
than i have and he has a strange one with his BMR torque arm.

It is the adjustable non cro moly version and when fitted (car is lowered around
1 1/4") the little bracket fixed to the underside in the vicinity of my mods bangs
onto the torque arm!









Just wondering if this is a common "fault" ?

Must just add that i would never give it back like that... A full powdercoat obviously!!

Trev

[SMWS6TA]

It being adjustable why wasn't it adjusted for the lower height?

[speedyWS6]

Scott....

Beats me.

Like i said, it's not mine. I have never tried to install one and i am not
au fait with any of the adjustment methods.

Looks to me like the two big adjustable rod end thingys connect to the diff somehow
to alter the rotation of the diff around the center of the axle?

Merely me just having a wild stab cos i have no idea!!

Having said all of that it would sound like you DO know and i shall have to get back
to Stu to find out more??


:0

[SMWS6TA]

It should have been set while the suspension is under load of the vehicle. You can do this by either a 4 post list you drive on or 4 jack stands. The 2 for the rear go under the axle and the front you level off. Using an angle finder place it on the pinon and check measurement. For this process up is negative and down is positive. F-bodies need a -2 angle. You then make adjustments to the heim joints to get the correct pinon angle. Any more or less will cause binding issues with the drive shaft u joints. Once you think it's set spin the drive shaft (while in neutral) and check for u joint clearance. Lock the heim joint.



Wish I could see how the front of the torque arm is set up. With my UMI torque arm I also go the transmission crossover that removed the torque arm off the tail cone. It has 4 locations that I could make adjustments at this location as well. Does the BMR have this?


Well too late seeing it's been modified already...

[pajeff02]

I am trying to picture what it is hitting on under there. I had to radius just the corner of the torque arm bracket back by the rear as it was hitting the tunnel under full compression. Other than that, there was lots of clearance everywhere else.

[speedyWS6]

This picture is a little grainy, but
you can see the culprit in the circle.



I'll send Stu a link to this to see what he thinks.
Me.... Never done it!

[pajeff02]

Ok - looks like the e-brake cable bracket. Guess I'll have to take a look next time our car is in the air to see what things look like. I have the UMI tunnel mount torque arm so it is rather large, although a bit shorter.

[SMWS6TA]

Yup e brake cable bracket.

I still don't see how that would be touching it.

[speedyWS6]

Nor me....

But it apparently does?

before i removed the section to replace the piece lower down
it showed evidence of marks put in by the clonking.

[SMWS6TA]

Could you take a pic of where it connects to the transmission and the rear?

Also did it "rub" when under a hard launch/bumps in the road or all the time?

Also how does it fit on the rear? is it close to the rear or out closer to the car body? I ask because with my torque arm I had to modify the holes for the bolts that secure the rear to the torque arm. Reason why is mine is a Ford 8.8 rear that I had a mounting bracket weld on to the housing. The bracket required me to notch the 2 holes on the torque arm that way I could adjust to get it snug to the drive shaft but not interfere with it and also clear the car body. Till I figure this out I was getting clonking noises every time I hit a bump.

[kingls1]

Maybe it for a 5th Gen! Dude you got to quit cutting big chunks of metal from things there are reasons it's there in the first place. Now don't get upset I like your fab work have done it professionally for many years but you really need to find solutions be for cutting into things. Your not the first to put a BMR arm on a f body.

[speedyWS6]

It's not mine.......

I have done it according to instructions from the owner!!!!!

I have never seen it fitted nor have I heard the banging.....

And don't get me started on the headers!! It is remarkable
how well the correct ones fitted.....

Scott... I'll talk to Stuart and get back to you on your questions.

[RONS98TA]

It is my guess that the BMR was designed for stock ride height. Even with the adjustments BMR put in the design of the t-arm, I don't think it will fit correctly under a car that has been lowered well over 1 inch. My car was lowered with The Eibach sportline lowering springs, that after they settled, my car was 2 inches lower then stock. Looked awesome, but had issue with speed bumps and torque arm. My e-brake bracket was also hitting, but further back in the tunnel closer to the dif. I replaced the springs with the next level to a higher stance so I would get the needed clearance. Obviously, Stuart has already made his choice. LOL

[SMWS6TA]

It is my guess that the BMR was designed for stock ride height. Even with the adjustments BMR put in the design of the t-arm, I don't think it will fit correctly under a car that has been lowered well over 1 inch. My car was lowered with The Eibach sportline lowering springs, that after they settled, my car was 2 inches lower then stock. Looked awesome, but had issue with speed bumps and torque arm. My e-brake bracket was also hitting, but further back in the tunnel closer to the dif. I replaced the springs with the next level to a higher stance so I would get the needed clearance. Obviously, Stuart has already made his choice. LOL

You just justified why I went with UMI Performance torque arm. I've never had an issue until I built my 8.8 rear but that's not UMI's fault. I've made a modification to make it work.

[speedyWS6]

And here is Stuarts answer in full!!

"Trev,

Had a quick scan through and heres an answer…

The reason for clearancing is that at full suspension travel with a fat git sitting in the passenger seat the top of the torque arm “can” hit the e-brake bracket. Especially when going over British speed humps.
Even just a light tap sounds loud and as you saw the powder coating got chipped. It doesn't happen on all cars as the e-brake bracket appears to be spot welded on not nearly as accurately as it would on a lunar landing module. The amount of clearancing you have done is by far and away enough to solve this problem. There are articles on LS1 Tech about this but not many so it does happen .."

Hope it makes sense, Scott and, like you, the stuff i have bought so far has also been UMI and fitted ok.

[SMWS6TA]

Love the "fat girl" comment.



And to be fair I'm a fat guy too

If he fine with it no issues. I was just trying to make sure it's not an incorrect setup.

ALSO FYI...when I was looking at springs/shocks/suspension setups 4-5 yrs ago I came across some info that GM used 3 different types of springs. Northern and NON US cars had higher ride height while southern and Cali cars had a slightly lower ride height. All due to different springs. I also read that it depended on their supplier at the time the car was assembled. I tend to believe the later reason more.

[weslp00]

Love the "fat girl" comment.



And to be fair I'm a fat guy too

If he fine with it no issues. I was just trying to make sure it's not an incorrect setup.

ALSO FYI...when I was looking at springs/shocks/suspension setups 4-5 yrs ago I came across some info that GM used 3 different types of springs. Northern and NON US cars had higher ride height while southern and Cali cars had a slightly lower ride height. All due to different springs. I also read that it depended on their supplier at the time the car was assembled. I tend to believe the later reason more.

Hi guys, i'm Stuart.. the one that Trev's been fixing the Torque arm for.
I usually hang out on the "alternative channel" ..LS1 Tech. I have a full signature on there and pics etc.

Yes as you've worked out the TA is hitting the e-brake bracket in extreme cases. The car is lowered all round on BMR/ Eibach springs so Trev came up with this ingenious idea to mod the arm with no strength compromise..
I dont think I ever want to lower the car by 2 inches.. thats riding on the bumpstops territory. Good scenario about the stock springs being different from manufacturer to manufacturer ! Maybe thats why you see so many different Trans am and Camaros on stock springs at different heights.
Has anyone worked out yet why the drivers side sits higher than the passenger side?

[SMWS6TA]

With my setup in my signature, both my front sit 26" from the bottom lip of the fender to the floor thru the center of the wheel and 27" on the rear.

I gained almost an inch from when I installed the Hotchkis springs over my stock springs. Mine were worn out I guess.

I did verified the front before I removed the LS1 and after I installed the iron LQ4 block. No change in height even with a 60-80 lb increase.





added signature to post

try this again

[SMWS6TA]

try this again


seems the site wants to screw with me. My signature is in post 10 of this thread

[pajeff02]

Welcome to the site, Stuart! You must be pretty desperate for friends if you're hanging out with Trevor.