Which aftermarket susp company has the closest tolerances/least NVH?
09-27-2008, 12:57 PM
#1
Which aftermarket susp company has the closest tolerances/least NVH? Reason i'm asking is is just installed a dbl adj phr with qa1 rod ends and have noticed that after i torqued the bolts, it still has some play in the ends, leading to a knocking noise.
I did some searching and found that some company's, (UMI and BMR were two that came up a few times,) are made with metric holes that have to mate up with the SAE holes in the car. ( i could have that backwards but you get the point.) This creates a bit of play that will obviously lead to NVH. One LS1Tech'er said that BMR sent him something to remedy that problem, but he had a good point in saying, if the company says these parts are a direct fit, why the hell aren't the holes the same diameter?
I also read that it's a good idea to use new bolts when attaching a new phr, which i didn't, but i will get some new ones soon.
My question is, if company's like UMI and BMR have this problem, is there really anyone out there that doesn't? I've got some UMI SFC's in the garage waiting to go in, now i'm thinking about not using them!
Anyone with first hand experience with this issue please chim in...
I did some searching and found that some company's, (UMI and BMR were two that came up a few times,) are made with metric holes that have to mate up with the SAE holes in the car. ( i could have that backwards but you get the point.) This creates a bit of play that will obviously lead to NVH. One LS1Tech'er said that BMR sent him something to remedy that problem, but he had a good point in saying, if the company says these parts are a direct fit, why the hell aren't the holes the same diameter?
I also read that it's a good idea to use new bolts when attaching a new phr, which i didn't, but i will get some new ones soon.
My question is, if company's like UMI and BMR have this problem, is there really anyone out there that doesn't? I've got some UMI SFC's in the garage waiting to go in, now i'm thinking about not using them!
Anyone with first hand experience with this issue please chim in...
09-28-2008, 07:53 AM
#4
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Good question, however from my experience, even the best of aftermarket, and even the factory can have these tolerance issues.
My suggestion? measure, remeasure, trial fit, and retrial fit to make sure everything lines up. If you may see a problem, then you will have saved yourself the trouble of dismantling, and worrying about warranty issues. If a fitment/quality issue may arise, then consult the vendor you have purchased from concerning their policy.
AFA the reusing the stock bolts with the aftermarket LCA's and PHB, not a good idea. Even if you grind them down to fit and/or they somehow appear to fit, it's best to get the appropriate sizes to fit so there will be less chance of wide tolerance and/or reliability issues in the long run.
FWIW, UMI makes a good product, and if you encounter a problem with the part, then you should consult them about it, because both you and the vendor can benefit.
My suggestion? measure, remeasure, trial fit, and retrial fit to make sure everything lines up. If you may see a problem, then you will have saved yourself the trouble of dismantling, and worrying about warranty issues. If a fitment/quality issue may arise, then consult the vendor you have purchased from concerning their policy.
AFA the reusing the stock bolts with the aftermarket LCA's and PHB, not a good idea. Even if you grind them down to fit and/or they somehow appear to fit, it's best to get the appropriate sizes to fit so there will be less chance of wide tolerance and/or reliability issues in the long run.
FWIW, UMI makes a good product, and if you encounter a problem with the part, then you should consult them about it, because both you and the vendor can benefit.
09-28-2008, 08:43 AM
#5
The holes in the car are metric, and the spacers most companies provide with their rod-ended components are SAE. UMI's LCA spacers are 1/2" through holes, and their panhard rod spacers are 9/16". When I put my stuff in, I just bored the holes in the rear end larger and used larger hardware, but you'll still have NVH problems even with the larger hardware when using rod ends.
09-28-2008, 09:23 AM
#6
The holes in the car are metric, and the spacers most companies provide with their rod-ended components are SAE. UMI's LCA spacers are 1/2" through holes, and their panhard rod spacers are 9/16". When I put my stuff in, I just bored the holes in the rear end larger and used larger hardware, but you'll still have NVH problems even with the larger hardware when using rod ends.
While I basically agree with this statement, I'll add that the factory bolts are actually two different diameters. The shank of the OE bolts, right at the head, is actually a bit larger than the threaded ends, and the holes in the chassis of the car are sized accordingly. Although I dont know for sure, I suspect this is to allow a little "wiggle room" to allow the LCAs to move in conjunction with the arc of the panhard bar, so as to not bind.
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09-28-2008, 10:55 AM
#8
I'm a little confused to what you are saying here?
We make our panhard bar sleeves at .560 and they use a 14mm bolt which is .550... you need a little bit of play in order to align the items porperly. If we made the holes too tight you would then be complaining because your bolt wouldn't go through the hole, correct?
Funny thing is the factory GM control arm holes measure .500 from the factory when GM uses a .472" 12mm bolt in this hole.
When working with a car that is 10-15 years old manufactures sometimes have to loosen there tolerances in order for a correct fit for every vehicle. I read an article somewhere that GM stated if there vehicle was built with in a .250" they were happy with that...
Also another thing to consider when building aftermarket items is metric tubing is almost impossible to find and purchase... this leaves us manufactures with standard size tubing.. this is tough with 90% of vehicles are built using metric bolts.
Thank you,
Ryan
We make our panhard bar sleeves at .560 and they use a 14mm bolt which is .550... you need a little bit of play in order to align the items porperly. If we made the holes too tight you would then be complaining because your bolt wouldn't go through the hole, correct?
Funny thing is the factory GM control arm holes measure .500 from the factory when GM uses a .472" 12mm bolt in this hole.
When working with a car that is 10-15 years old manufactures sometimes have to loosen there tolerances in order for a correct fit for every vehicle. I read an article somewhere that GM stated if there vehicle was built with in a .250" they were happy with that...
Also another thing to consider when building aftermarket items is metric tubing is almost impossible to find and purchase... this leaves us manufactures with standard size tubing.. this is tough with 90% of vehicles are built using metric bolts.
Thank you,
Ryan
09-28-2008, 10:07 PM
#10
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Tru on the factory tolerances okay to be off, and the aftermarket tightening these parts up for us for a better ride. But on the Moser 12 bolt is drilled for SAE threads and most aftermarket TQ arms are made for metric. Well at least three that I have used. Havent used UMI stuff yet so no comment.
09-29-2008, 11:25 AM
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I have the UMI adjustable PHR and I don't have any noise issue, even after 3 years. The clamp load of the bolt/nut is what keeps the spacer in place, not the bolt to spacer clearance. check to make sure you torqued the bolt/nut to spec, and for good measure, use a little blue loctite to keep it from coming loose.
06-23-2009, 11:53 AM
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I'm a little confused to what you are saying here?
We make our panhard bar sleeves at .560 and they use a 14mm bolt which is .550... you need a little bit of play in order to align the items porperly. If we made the holes too tight you would then be complaining because your bolt wouldn't go through the hole, correct?
Funny thing is the factory GM control arm holes measure .500 from the factory when GM uses a .472" 12mm bolt in this hole.
When working with a car that is 10-15 years old manufactures sometimes have to loosen there tolerances in order for a correct fit for every vehicle. I read an article somewhere that GM stated if there vehicle was built with in a .250" they were happy with that...
Also another thing to consider when building aftermarket items is metric tubing is almost impossible to find and purchase... this leaves us manufactures with standard size tubing.. this is tough with 90% of vehicles are built using metric bolts.
Thank you,
Ryan
We make our panhard bar sleeves at .560 and they use a 14mm bolt which is .550... you need a little bit of play in order to align the items porperly. If we made the holes too tight you would then be complaining because your bolt wouldn't go through the hole, correct?
Funny thing is the factory GM control arm holes measure .500 from the factory when GM uses a .472" 12mm bolt in this hole.
When working with a car that is 10-15 years old manufactures sometimes have to loosen there tolerances in order for a correct fit for every vehicle. I read an article somewhere that GM stated if there vehicle was built with in a .250" they were happy with that...
Also another thing to consider when building aftermarket items is metric tubing is almost impossible to find and purchase... this leaves us manufactures with standard size tubing.. this is tough with 90% of vehicles are built using metric bolts.
Thank you,
Ryan
06-23-2009, 12:53 PM
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I'm looking at the poly or rod-end combo and looking at a couple of things. I'm looking to eliminate the axle jolt when hitting a bump while cornering that makes the axle feel like it is moving out from under center. I'm guessing rod ends are going to eliminate this deflection but my vehicle is also a daily driver that I don't want a lot of noise, vibration, harshness.
In the PHB I'm lowering the car and looking to 1) re-center the rearend and 2) eliminate the axle jolt but retain stock or near stock NVH.
Will the poly/poly have the same deflection as the stock bushings and/or how noisy are the rod ends on the axle or axle and body if going with rod ends on both ends.
06-23-2009, 12:57 PM
#15
The factory panhard bar bolt is a step bolt, it has a 14mm shank but uses a 12mm thread. This way the bolt can't be put in wrong. The 14mm shank which is .550 is what goes through the PHB sleeve... Our sleeve hole is .560.
Rod ends, may over time because noisy. Since the car is a daily driver and you are concerned about additional road noise I recommend this panhard bar- www.umiperformance.com/2029
If you have any questions please let me know. Thank you!
Ryan
Rod ends, may over time because noisy. Since the car is a daily driver and you are concerned about additional road noise I recommend this panhard bar- www.umiperformance.com/2029
If you have any questions please let me know. Thank you!
Ryan