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NVH increase with LCA & UCA upgrade (W/poly bushings)


patrickshelby

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I got a small increase with the poly UCA and poly/rod end LCAs. At a later date I installed the poly bushing on the top of the diff. Definite increase in NVH but it also made a noticeable difference in axle control. It's also a PITA to install, but I'd do it again. It's all BMR.

 

Steve

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I have the Roush upper and the bmr lower with poly and a bmr panhard bar

With the race ends and have no extra noise. But you do need to grease the lower

with the poly ends.mine need to be done and now.you know when they need it

Because the bushing start to make a creaking noise.

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patrickshelby - you will get an increase with changing the bushings - I would recommend the BMR LCA that has a poly front bushing w/spherical rear bushing . As far as the bushing on the top of the differential - I recommend the spherical unit from Steeda. those two items will free up the articulation of the rear axle and make a huge difference. As far as the UCA - if you are going to a 1 piece driveshaft - you will need an adjustable one - BMR or Roush are both good - use one with a poly bushing ( note - when assembling an UCA to the bracket check for proper fitment - no play - no binding - do this off the car - check for looseness when bolt is installed and then torque bolt to required tightness and then check for binding - if all is good - then install ) but if you are sticking with a stock driveshaft the stock or Roush replacement is good ( however you must install and then torque down the bolt with the car sitting on the ground or with the wheels on a drive on rack with the vehicle weight on the suspension because of the design of the bushing ) .

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patrickshelby - you will get an increase with changing the bushings - I would recommend the BMR LCA that has a poly front bushing w/spherical rear bushing . As far as the bushing on the top of the differential - I recommend the spherical unit from Steeda. those two items will free up the articulation of the rear axle and make a huge difference. As far as the UCA - if you are going to a 1 piece driveshaft - you will need an adjustable one - BMR or Roush are both good - use one with a poly bushing ( note - when assembling an UCA to the bracket check for proper fitment - no play - no binding - do this off the car - check for looseness when bolt is installed and then torque bolt to required tightness and then check for binding - if all is good - then install ) but if you are sticking with a stock driveshaft the stock or Roush replacement is good ( however you must install and then torque down the bolt with the car sitting on the ground or with the wheels on a drive on rack with the vehicle weight on the suspension because of the design of the bushing ) .

 

Thank you for the advise Albino500

On my 2007 I had the Steeda LCA (billet alum. with heim & poly) and the Steeda UCA (adj. with heim & poly).

It was a bit loud...but I agree it was on rail.

So now for my 2012 I was considering having full poly to lower the noise.

That's why I ask.

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Did not know that you picked up a 2012 - congrats on that - IMO the poly is just as loud if not worse because of the creaking noise when it is binding and/or needs grease . You might want to go to just LCA's w/poly on both and leave the rest stock. JMO

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Did not know that you picked up a 2012 - congrats on that - IMO the poly is just as loud if not worse because of the creaking noise when it is binding and/or needs grease . You might want to go to just LCA's w/poly on both and leave the rest stock. JMO

 

 

Do rubber bushings cause binding as well? I have never heard a creaking noise from the car.

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Did not know that you picked up a 2012 - congrats on that - IMO the poly is just as loud if not worse because of the creaking noise when it is binding and/or needs grease . You might want to go to just LCA's w/poly on both and leave the rest stock. JMO

 

 

Got it!

LCA w/poly both ends & grease fittings (!).

Sounds good, I'll try that first.

thx

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Do rubber bushings cause binding as well? I have never heard a creaking noise from the car.

 

The stock rubber bushings are bonded to the bushings shell and center metal sleeve - they need to be tightened when the vehicle is loaded ( on the ground ) so that when the vehicle is just sitting the bushing is NOT in bind ( twisted - aka = loaded ) . The bushings on both the UCA and differential along with the LCAs are voided so that they can give/comply when they have a load applied to them (forward / back) and absorb the "road shock" and torque twist of the rear axle . However , they are designed to go into bind/twist when the suspension travels up/down ( the center sleeve is locked into place to the body and axle mounts when you tighten down the bolt ) . The only time I have found a noise issue from a stock bushing is when either the bolt was not tight , rust had formed on the sleeve , or when the bushing had gone bad . Really if you pay close attention to the fitment of aftermarket parts w/poly or spherical ends you should not get any more noise than stock - just an increase in harshness and more sensitivity to pre-existing vibrations/harmonics.
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The stock rubber bushings are bonded to the bushings shell and center metal sleeve - they need to be tightened when the vehicle is loaded ( on the ground ) so that when the vehicle is just sitting the bushing is NOT in bind ( twisted - aka = loaded ) . The bushings on both the UCA and differential along with the LCAs are voided so that they can give/comply when they have a load applied to them (forward / back) and absorb the "road shock" and torque twist of the rear axle . However , they are designed to go into bind/twist when the suspension travels up/down ( the center sleeve is locked into place to the body and axle mounts when you tighten down the bolt ) . The only time I have found a noise issue from a stock bushing is when either the bolt was not tight , rust had formed on the sleeve , or when the bushing had gone bad . Really if you pay close attention to the fitment of aftermarket parts w/poly or spherical ends you should not get any more noise than stock - just an increase in harshness and more sensitivity to pre-existing vibrations/harmonics.

 

 

When you say harshness you mean more bumpy? The LCA or UCA can do that? So then since they bind or twist when the suspension goes up down as in for example going over bumps that is when they twist, and if we use spherical ends then those solve this twisting? Also since I'm learning about all this suspension stuff why is binding/twisting bad? When do poly bushings bind/twist?

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Binding causes a change in spring rate thus causing a change in ride quality and response change in other dynamics . If installed correctly spherical and poly bushings do NOT go into a bind when twisted. The problem occurs when they are NOT installed properly (ie the installer does not check to see if the center sleeve is a slight bit longer than the bushing so it can be locked into place with the mounting tabs without the side of the poly portion being crushed to the point that it does not rotate with the arm). You need to check each end of the control arm by mounting it and then swing it through its travel making sure that the center sleeve stays still and the poly / spherical portion rotates with the arm and you need to check that you do NOT have an excessive amount of play also . Binding will cause premature wear on parts.

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Binding causes a change in spring rate thus causing a change in ride quality and response change in other dynamics . If installed correctly spherical and poly bushings do NOT go into a bind when twisted. The problem occurs when they are NOT installed properly (ie the installer does not check to see if the center sleeve is a slight bit longer than the bushing so it can be locked into place with the mounting tabs without the side of the poly portion being crushed to the point that it does not rotate with the arm). You need to check each end of the control arm by mounting it and then swing it through its travel making sure that the center sleeve stays still and the poly / spherical portion rotates with the arm and you need to check that you do NOT have an excessive amount of play also . Binding will cause premature wear on parts.

 

 

I see. I will make sure to remind my installer about this when I put my bobs ones on. Though he's worked on my shelbys so he probably already knows this but this is great information to check to be 100% safe.

 

What about with UCA? Or do the same things apply? I'm also wondering how come UCA with poly bushings let more noise thru than LCA with poly bushings

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After a few thousand miles on my suspension upgrades I've found that if I heard any extra noise it was because something had come lose. After I went through everything and re torqued it I've been quiet as stock.

 

 

Even with the Steeda UCA? That is surprising.

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I know. I had a bit of gear noise after installing it. I checked and adjusted the opinion angle and noose went away.

 

 

Maybe instead of the roush OEM look a like I should look into whiteline UCA since their bushings seem to be the best on the market right now.

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Maybe instead of the roush OEM look a like I should look into whiteline UCA since their bushings seem to be the best on the market right now.

 

Maybe you should look closer at the WL unit because it has an offset hole in the center sleeve - not only will you need the talent to set the pinion angle by rotating that sleeve but hold it while you tighten the bolt in order to lock it in place along with hoping that it does not come loose and rotate thus throwing the pinion angle way off. JMO
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I see. I will make sure to remind my installer about this when I put my bobs ones on. Though he's worked on my shelbys so he probably already knows this but this is great information to check to be 100% safe.

 

What about with UCA? Or do the same things apply? I'm also wondering how come UCA with poly bushings let more noise thru than LCA with poly bushings

 

Yes that applies to the UCA also and it transmits more noise because of it 's mounting point to the unibody (center of floor on backbone vs outer corners under rear torque boxes for the LCA)
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Maybe you should look closer at the WL unit because it has an offset hole in the center sleeve - not only will you need the talent to set the pinion angle by rotating that sleeve but hold it while you tighten the bolt in order to lock it in place along with hoping that it does not come loose and rotate thus throwing the pinion angle way off. JMO

 

 

Well I wouldn't be doing that the mechanic would. Is what your saying difficult to do? I rather not go the steeda route since these bushings are better.

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Well I wouldn't be doing that the mechanic would. Is what your saying difficult to do? I rather not go the steeda route since these bushings are better.

 

Explain to me why they are better and I don't know what is difficult for your mechanic to do or not - ask him if it's difficult.

Maybe instead of the roush OEM look a like I should look into whiteline UCA since their bushings seem to be the best on the market right now.

 

Again - please explain to me why/how their bushings are the best.
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So far everyone who has used whiteline products seem to think they are the best. Apparently their bushings are said to be high quality and maintence free. They also apparently are better at insulating noise. I don't know much about them just from what I read from searching. I was waiting for someone to do a write up on their watts link. I feel that would be the test because if their bushings could keep a watts link quiet then maybe it would do the same for an UCA.

 

But they do have the best bushing in Australia apparently and are the supplier for the OEMs out there. They also seem to rule the import car aftermarket.

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Lots of good info in this thread, I'll confirm a few things and add a few:

 

1. Poly bushings have less "give" than rubber, so an increase in NVH is very possible. So is the intended benefit of more controlled, "tighter" handling.

2. They need to be greased. If not, they will creak eventually. I still have to lube my FRPP swaybar endlink bushings from time to time, or speed bumps make it creak like a rusty old garden gate.

3. They need to be finally tightened ONLY when the suspension is under load, to prevent pre-loading them in the wrong position. Then they will always be "twisted" somewhat. This decreases their effectiveness and makes them creak, too.

4. Watts links LOCATE the axle, control arms carry a lot of weight. So the odds of a Watts link adding more or less noise is not as significant as LCAs or a UCA. They can increase the RESONANCE of any noise, simply because most include a frame-mounted crossmember (the "frame") that gives the benefit of lower chassis bracing, but can help it "ring" at a different (higher) frequency. That sloppy "thud" when you hit a bump becomes a higher note, like tightening the head on a drum. Not a bad thing, but many people hear it as a "new noise".

5. "Race ends" were designed for racing. They were not designed to be sprayed with sand, salt, and crud on a daily-driven car. So keeping them clean is a must. Most of our "race end" products are Teflon-coated, for easier cleaning. But they still need to be cleaned!

 

 

 

Jer

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5. "Race ends" were designed for racing. They were not designed to be sprayed with sand, salt, and crud on a daily-driven car. So keeping them clean is a must. Most of our "race end" products are Teflon-coated, for easier cleaning. But they still need to be cleaned!

 

Jer

 

 

 

Jer, the Teflon in a rod end doesn't utilize a coating but rather a fabric/weave.

 

Teflonlinedrodend.jpg

 

sphericalbearing.jpg

 

Self lubricating and with a rather low coefficient of friction. If you are 'coating' anything with Teflon for easier cleaning I'd be interested to see more about what you are referring to.

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Lots of good info in this thread, I'll confirm a few things and add a few:

 

 

3. They need to be finally tightened ONLY when the suspension is under load, to prevent pre-loading them in the wrong position. Then they will always be "twisted" somewhat. This decreases their effectiveness and makes them creak, too.

 

 

 

 

Jer

 

This is only true with rubber - torsional-elastic bushings not with polyurethane bushings !
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Corrections:

While I was trying to get the point across that all suspensions should be tightened and torqued at "loaded" position, Mr. Albino clarifies further. OK.

As for the Teflon: Well, I did say "coated", rather than "lined", so thanks for that clarification.

 

 

To compliment the upper control arm, two styles of lower control arms are offered to match your specific vehicle purpose and handling needs: The ‘Street Version’ has self-lubricating UHMW (Ultra High Molecular Weight Polyethelene) bushings in the body side with a self contained self lubricating Teflon/PTFE lined race spherical bearing in the axle side, or the ‘Race Version’ that uses high grade ¾" chromoly self-lubricating Teflon/PTFE lined race rod ends.

 

 

Jer

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This is only true with rubber - torsional-elastic bushings not with polyurethane bushings !

 

 

BTW, This is from BMR Fabrication's Installation Instructions for their poly-bushing UCA:

 

If using part number UTCA017, the rear end must be loaded before tightening the bolts. To do this, lift the rear to ride height and then tighten the control arm mounting bolts. Tighten both cross-bolts to 129 ft/lbs.

  1. NOTE: Failure to load the suspension before tightening these bolts can result in premature bushing failure due to bushing pre-load.

 

 

 

Jer

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BTW, This is from BMR Fabrication's Installation Instructions for their poly-bushing UCA:

 

If using part number UTCA017, the rear end must be loaded before tightening the bolts. To do this, lift the rear to ride height and then tighten the control arm mounting bolts. Tighten both cross-bolts to 129 ft/lbs.

  1. NOTE: Failure to load the suspension before tightening these bolts can result in premature bushing failure due to bushing pre-load.

 

 

 

Jer

 

That I believe Jer is because of the rubber bushing that is pressed into the top of the differential (which UTCA017 attaches to) is a torsional - elastic bushing ( it has voids in it and is bonded to the inner sleeve and outer shell) and is what BMR is refering to. Just trying to share with people what to look for when installing parts so as not to have issues after the install - seems to be a lot of people whom complain about noise issues after installing such things.

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That I believe Jer is because of the rubber bushing that is pressed into the top of the differential (which UTCA017 attaches to) is a torsional - elastic bushing ( it has voids in it and is bonded to the inner sleeve and outer shell) and is what BMR is refering to. Just trying to share with people what to look for when installing parts so as not to have issues after the install - seems to be a lot of people whom complain about noise issues after installing such things.

 

 

Well, we're both after the same thing - happy, safe motorists.

I just wanted to establish a basic principle that will serve most situations best: "Load it before you torque it".

I would also add: "Then check it after a day or two!"

 

:)

 

Jer

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Well, we're both after the same thing - happy, safe motorists.

I just wanted to establish a basic principle that will serve most situations best: "Load it before you torque it".

I would also add: "Then check it after a day or two!"

 

:)

 

Jer

 

AGREED - GOOD ADVICE JER !
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