Rod End vs Bushings

[Flash_of_Yellow]

Hey Guys,

I'm thinking of getting some UMI LCA's and adjustable panhard bar. I keep going back and forth between the rod end/bushing combo or the double rod end parts.

Does anyone have any comments on their setups with the double rod ends? What kind of noise will I get? Will it vibrate enough to cause the interior panels to vibrate as well... I hate rattles.

My car is 75% track only car, and 25% weekend play. Never a daily driver. But I will do a long distance trip if needed, such as 7 hours next month to get my roll bar fabbed and welded in at my dad's shop. Thanks.

 

[Flash_of_Yellow]

Guess I should have searched first, sounds like the double rod end parts will be noisy as hell. Sound about right?

Second question then.. for those running the noisy control arms, are they worth it for what you get out of them on the track or do you wish you had done the bushing and rod end combo?

 

[Bizzyb0nes]

my rod ended PHB, LCA, and UCA arent that bad...I'm sure something with poly bushings would be alot quieter and more comfortable...and to some degree i'd prefer it, but I truly dont find it bad enough to warrant switching, the performance outweighs the noise imo

 

[DusterRT]

I've been considering going to rod ends (got a screaming deal on a set of MM LCA's a while back..why not complete the set eh?). I'd cut you a heck of a deal on my CHE setup: adjustable PHB, adjustable LCA's, fixed UCA and UCA mount.

These have a nifty Delrin lined poly bushing that's dead silent and silky smooth (http://www.cheperformance.com/Tech/CHE_Poly_Delrin_Bushing.html). I get a little gear whine inside on deceleration and moderate to hard acceleration but nothing offensive. Poly bushing squeak is for suckas!

 

[Bingo]

I have the Edelbrock LCAs...the axle side is a spherical and the body side is a poly. The poly squeaks and the spherical brings gear whine into the cabin...I think I prefer the whine over the squeak.

 

[Kaldar142]

I have rod ended LCAs and they are much louder than the poly bushing LCAs i used to have. I don't mind though, although i don't mind my super loud exhaust either lol.

 

[pcdrj]

I have rod ends on sway bars, lca's, watt's link. NVH is noticeable but tolerable.

 

[GRAYPNY]

I used to have poly/poly BMR LCA's and one of the bushing broke. Now I have the UMI LCA's poly/rod end and it makes a little noise but at least the LCA's work!

 

[SoundGuyDave]

My personal take on the debate:

1) Unlike a drag car, a road course car needs the axle to articulate in more axes than just the longitudinal...

2) Poly bushings are GREAT at transferring launch energy into the chassis, but when you try to twist the axle in relation to the chassis (one side up, the other down) like in a turn, it puts the poly bushings into bind, actually reducing the "smoothness" of weight transfer to the outside.

3) That bind, combined with the poly bushings' stiffness will cause failure. Period.

4) With the above as a given, poly bushings are on borrowed time for a corner carver from the DAY YOU INSTALL THEM.

5) It took me a grand total of seven track days to TOTAL a set of poly/rod LCAs.

6) QED.

You want either the low durometer stock rubber bushings, a substitute for same that allow torsional motion, or rod ends. Period.

 

[DusterRT]

5) It took me a grand total of seven track days to TOTAL a set of poly/rod LCAs.

How did they fail? Did the bushing tear? Seems just about every poly joint that I see failed looks like it was just chewed up from the inability to keep the joint lubed properly (smooth bushing on a smooth sleeve is going to act like a squeegee on the lube and the joint likely runs dry quickly).

One of the things that I like about the CHE design, and the sole reason I chose them, is the Delrin and steel sleeve eliminate the torsional force on the bushing (the Delrin insert rotates on the steel bushing, the poly bushing sees little to no torsional stress and only locates/isolates the control arm). I've got 15,000 street miles and a half dozen or so track days on them over the past year and haven't had to touch them...I feel no slop in the arms and no visible degradation of the bushing and have been virtually silent since day one. I've had poly bushings in several other cars previous to this and if they didn't self destruct, they got noisy before too long. I have no reservations whatsoever in saying they're superior to any other conventional poly joint, otherwise I'd be agreeing with you.

"If they're so great, why would you change?"

Frankly, I'm just curious...I want to see how they compare to each other as far as NVH, performance, and life-span of the rod ends. I've been working on a little project of sorts and I feel it would be a valuable "data point" I guess you could say. Now that CHE is making their control arms again, I can always get them again if I want/need to.

 

[Flash_of_Yellow]

Wow guys, thanks for all the replies. I think I've decided that rod ends are the way to go. It's easier to deal with a rattle I don't like than to deal with poly bushings that are broken. One is annoying but the other takes the car out of service.

Now just have to wait for UMI to have another 15% off holiday sale...

 

[SoundGuyDave]

How did they fail? Did the bushing tear? Seems just about every poly joint that I see failed looks like it was just chewed up from the inability to keep the joint lubed properly (smooth bushing on a smooth sleeve is going to act like a squeegee on the lube and the joint likely runs dry quickly).

Mine failed in the pretty typical way.... Out on track, in mid-corner, I heard a "CLACK," and suddenly the rear would rotate out to the right under throttle, and rotate out to the right under deceleration. End of the day, obviously, and the 50 mile drive home wasn't exactly fun.

I tore the rear suspension down, and the first bushing (driver's side) that I inspected was kind of ovaled out, probably around .010 at the ends, but still fairly tight in the center. The passenger side, though, let's just say the bushing exploded, and when I pulled the arm, the sleeve just fell out of the bushing, along with a few chunks of polyurethane. I called Maximum Motorsports the next day and got the all-rod LCAs and PHB. I probably didn't need to change the PHB, but I just figured that as long as I was making the swap, I might as well.

My belief is that the motion of the axle under cornering puts a load on the bushing that is uneven, stressing the front portion on one side of the bushing, and the rear portion on the other side of the bushing, and without the compliance of the softer rubber stocker, they just tear themselves apart. Big difference from the dynamics of a drag launch, or even just driving around on the street.

The load on the PHB for example, is all linear through the bushing, where the inner sleeve stays pretty much parallel to the outer loop. Not so much with the control arms trying to twist both with the roll-axis of the axle, and the short arc in and out tracking the PHB.

 

[Marc s]

I also had poly's at first. After about 10 track days the right front bushing failed on a 100 MPH corner. I replaced them all with rod ends the next day. The handling improved and the noise is minimal.

 

[Vapour Trails]

I have the J&M LCAs that feature a articulating polyurethane joint. I too did not want the binding of a traditional poly bushing.

After I bought them a person came forward and said they are flawed, although I could never figure out his exact argument against them. Almost seemed like a personal vendetta against the company.

I'm sure the bushings in the poly-joint will deteriorate over time, but the manufacturer gives a lifetime bushing replacement guarantee.

For me, a rod end was never in the cards. My car is a DD and I absolutely abhor NVH. I was just thinking to myself yesterday as I drove over the pockmarked and cracked pavement of my city how pleased I am will the ride quality and silent operation of my suspension. My car rides better than my wifes stock acura which is very softly sprung.

 

[DusterRT]

I have the J&M LCAs that feature a articulating polyurethane joint. I too did not want the binding of a traditional poly bushing.

After I bought them a person came forward and said they are flawed, although I could never figure out his exact argument against them. Almost seemed like a personal vendetta against the company.

I completely forgot about those..I really like them as well. Probably more than the Delrin-sleeved bushings if they don't squeak. I agree though, that guy who had the big beef with them never really did say why they were flawed..definitely seemed personal more than anything.

 

[Blair]

I completely forgot about those..I really like them as well. Probably more than the Delrin-sleeved bushings if they don't squeak. I agree though, that guy who had the big beef with them never really did say why they were flawed..definitely seemed personal more than anything.

The guy who had the problem with them was f1fan/ponydna/chip. IIRC he thought that they were no different than regular poly bushes because the ball was completely enclosed on both sides by poly that encased the sleeve. Basically a poly ball completely encased by poly ends that was functionally no different than a solid poly bushing. If you made the end pieces soft enough allow the sleeve to articulate then the ends would get completely torn up in no time. If you made them hard enough to resist being torn up, you are basically left with a what is essentailly a regular solid poly bushing because the poly ball wouldn't be able to rotate.

 

[Vapour Trails]

The guy who had the problem with them was f1fan/ponydna/chip. IIRC he thought that they were no different than regular poly bushes because the ball was completely enclosed on both sides by poly that encased the sleeve. Basically a poly ball completely encased by poly ends that was functionally no different than a solid poly bushing. If you made the end pieces soft enough allow the sleeve to articulate then the ends would get completely torn up in no time. If you made them hard enough to resist being torn up, you are basically left with a what is essentailly a regular solid poly bushing because the poly ball wouldn't be able to rotate.

I would imagine that the outer bushings would be chewed over time by rotation of the inner ball. I recall one guy, maybe Rodeoflyer, said the LCAs worked like they were designed (didn't bind), but destroyed the bushings after a period of time.

However, if they will send me new bushings for the life of the part, I'm ok with it.

Given what I know now, I may have opted for their "extreme" joint LCA.

 

[Kobie]

These look nice!
http://www.lmperformance.com/image.asp?p=m5-205-4130&m=52

 

[Blair]

The general consensus in this thread is that rod ends add road noise and maybe let more gear whine through. However, I ran across a thread on a GT500 forum where a guy installed rod ended parts LCAs and a PHB and said there was no increase in noise level at all:

http://www.svtperformance.com/forum...-parts-mm-xd-rlcas-panhard-bar-roush-uca.html

How is it that he did not get a noise increase, but everyone else does? Maybe because he retained a rubber bushing in the UCA?

 

[Vapour Trails]

How is it that he did not get a noise increase, but everyone else does?

Noise is subjective, and people lie.