imflyn

iTrader: (2)

Just thought I'd share the fix I just did on my torque arm. I upgraded to the UMI unit with the new trans cross member that takes the mounting off the transmission but keeps the stock length of the torque arm. Well, after I installed it last year I was hearing a clunking noise and the opinion on the forums and from umi seems to be " yeah it's after market with more solid mounting. It's going to make noise, or it's hitting the tunnel" (it's not even close to hitting the tunnel)

This didn't seem right so I put the car on ramps so the suspension would be loaded and rocked and rolled and twisted on the driveshaft and tracked down the noise. The two bolts that run through the torque arm at the back! Not the long 8" bolts, the short ones that run through the hiem (sp?) joints. There is just enough play between the shoulder of the bolt and the ball socket that as the axle tries to twist clockwise then counter clockwise (slow driving over bumps, etc.) the arm would shift ever so slightly and clunk.

I bought some .005" brass sheet metal and made my own bushings for the bolts. They filled the void nice and tight and after a test drive the noise is gone. This indicates a .01" gap, plenty to rattle and make noise. Hopefully UMI will take this advice and supply this sleeve for future customers.

I suspect that all the complaints about noise from aftermarket suspension could be attributed to the same sort of play in the bolts. Everything was torqued mind you. It was the play between the shoulder and the socket that the bolt runs through that was making the noise.

Hope this helps some people quiet down their ride. I know it was annoying the crap outta me!

high impact

iTrader: (5)

Nice find! My tunnel mount arm is making a racket - I am going to go through my rear suspension with a fine tooth comb like you did b/c it's driving me nuts too

SSellers

Yeah, pretty poor. My UMI subframe connectors came with standard shoulder bolts for the rear control arms to replace the factory metric ones. Gotta figure there's going to be mismatches.

blackbird0230

mine clunks so bad, people think the car is going to break. I'll definitely try this

BlackBetty99SS

iTrader: (1)

Wonder of this is the same w the bmr tq arm I have on my car. Excellent find sir. Been tempted to just switch back to stock arm bc the NVH.

UMI Performance

iTrader: (77)

Hello,

Thanks for sharing your fix

This is what makes hot rodding fun... when people are creative when it comes to things on their vehicle they would like to see different. Congrats!

For us, the 0.010" is needed for assembly purposes and powder coat allowance. Powder coat can build up from 0.005" to 0.015" per side. If the powder was slightly heavier, lets say 0.005" on both sides then the rod eye would be extremely tight, that would add 0.010". It is a tolerance we have to have. We can control our powder coat very well, but controlling it within thousands is very tough. Sometimes if the powder gets a little heavier the rod eyes won't fit in place. If there is a small gap like you saw of 0.010" we usually tighten the 5/8" bolts to take up the space, I will admit that two pieces of 3/8" steel are tough to compress but is doable. Your shim idea is a great idea. But depending on powder coat this space will change each time.

As for other noises, there are many other causes. Vehicles with larger rear ends or lowered will hit the tunnel in the rear. Tunnel mounted torque arms that bolt under the seat offer a more solid mount and can increase NVH, also loose bolts are a big factor. Most nuts used on the torque arms are lock nuts, they require more force to tighten so keep that in mind.

When we talk about measurements I do get a lot people that don't know what a thousands of in inch is. So to help some understand, your finger nail is usually around 0.015" thick, 1/3 of your nail thickness would be 0.005"

Thanks again for sharing, glad to hear it worked out for you!
Ryan

01ssreda4

iTrader: (96)

Gotta go with UMI on this one. That's way to tight of a clearance for such an application and price point. The fact that it was as close as it was is very impressive.

1 FMF

iTrader: (1)

thanks for the post. just put a new axle in and am using the umi adjustable long torque arm. i noticed immediately when installing the bolts that hold the tq arm ends in the bracket on the axle that there was some play. i did this with the axle prior to install on the garage floor and testing the tq arm fit to axle. but i think i managed to tighten those bolts enough where the torque arm won't rattle around, at least i could not cause it to happen from hand strength.
i have clunks back there currently at low speed rough roads but i think it's the sway bar. will know when i remove it to verify.

question to umi, it's nice and all to have powder coating but why not powder coat the steel bracket first prior to drilling then drill the bracket so the hole is the same diameter as the bolts going through?

ThoR294

iTrader: (6)

I get a clunk when changing directions (Forward -> reverse, and vice versa). I have a feeling its something shifting (I have a uMI arm with relocation as well) wonder if its related

UMI Sales

iTrader: (1)

Machining or drilling after powder coat would be next to impossible. We are held to an incredibly high standard with regard to powder coat finish. Clamping and holding without blems is tough.

The rod eye bolts are 5/8" diameter. You can tighten them with enough force that the rod eye doesn't move.

Fixing manufacturing tolerances and optimizing things is part of our car hobby and is what some owners do. The majority of customers bolt our stuff on and go for years with nary a clunk.

camarokid91

Interesting my BMR bar makes noise, but it was on the second time I installed it. The first install was quiet now it like to bang and let me know it there. I will have to look into adding a shim or something to quiet it.

HoLLo

iTrader: (17)

Mine does the same, and I've never been able to figure out what it was. I never once thought to check those two bolts. I will try and torque the hell out of them.

Sommer86

iTrader: (46)

I'll check your method on my car. I have UMI everything (LCA's, Re-lo's, SFC, On car PHR, Strano's and Koni's) and now have crazy clunk/rattle. It just started 2 months ago, and this car had bee na DD for 6 years. And the stuff has all been installed for 4.

However, there is no loss in performance or car drift on the road, and the sounds goes away in the rain. When it starts to dry out again, it starts to clunk.

I went under the car the other day and NOTHING is loose or moves. Weird.

blackls1ta00

iTrader: (27)

my umi makes same annoying clunk!!

UMI Performance

iTrader: (77)

Honestly, we have found 90% of torque arm noise has resulted from loose bolts. So check all mounting bolts! Also remember all bolts have locking nuts, so a locking nut can make the bolt appear tighter than it is.

Hope that helps,
Ryan

HoLLo

iTrader: (17)

About two months ago I was under my car and found the two large torque arm mounting bolts slightly loose (not too loose to wiggle, just loose enough I was able to tighten the nuts back easy), and tightened them to spec, which if I recall correctly was 90ftlbs. After a test drive, I still had the clunk, so it has to be the horizontal bolts through the heim joints. I never once thought to check those.

ThoR294

iTrader: (6)

I never checked those either, i Just checked the 2 vertical bolts.

imflyn

iTrader: (2)

I just thought I'd clarify that the bushing I made wrapped around the bolt and slid through the hiem joint horizontally, not a washer type spacer.

The thickness of powder coat had nothing to do with play between the bolt and hiem joint. Both are bare metal.

After I first installed I found the jam nut on the adjustable part had backed off, so that's another place issues can creep up. Like the UMI spokeman said, torque those bolts!

01ssreda4

iTrader: (96)

Well that's interesting.

Flubyux2

It could be the difference from the shank diameter of supplied bolts vs Oem bolts.

I have a bunch of nvh in my car. I think it all stems from my M9 though. The center section being so much wider than stock causes the torque arm to run at a wider angle away from the driveshaft. So my arm rubs the driveshaft tunnel. It's split the sheet metal towards the rear. Any bumps that the rear axle hits is transmitted directly to the body of the car.

On top of this, my bolts on the heim plates are too long and hit the body too. This has cracked the sheet metal.

Also, I'm not sure cars were meant to be lowered with the m9. The top threaded sleeve on the diff contacts the body too. That's gouged the metal and literally knocked a notch into it.

Rubbins racing though!