World record Thrust arm longevity?

[632 Regal]

My FCP Hamburg test results are in....

I have almost 10k miles on my FCP thrust arms and the busings are giving the 55-65 shake!!! woohoo look at all the money I saved and the fun I had, cant wait to do this all over again in less than a few months.

AMEN for cheap parts, if not for that what fun would I have! This is with their self proclaimed 750 bushings too.

I think I'll join in the group buy and get a few sets, maybe I can make it to a year with all of em.

[rob101]

hmmmmm, has anyone thought of setting a spherical bearing in place of the bush?

[tim s]

but i would not buy them.

hmmmmm, has anyone thought of setting a spherical bearing in place of the bush?
tim s.

[rob101]

i was thinking more along the lines of SKF.

[winfred]

the new guy at my shop made it a whole week on his hamburg technic e30 m3 control arm bushings before one took a ****, i installed them so i know they didn't get ****ed up in instalation. lemforder arms and m5 bushings!!!


My FCP Hamburg test results are in....

I have almost 10k miles on my FCP thrust arms and the busings are giving the 55-65 shake!!! woohoo look at all the money I saved and the fun I had, cant wait to do this all over again in less than a few months.

AMEN for cheap parts, if not for that what fun would I have! This is with their self proclaimed 750 bushings too.

I think I'll join in the group buy and get a few sets, maybe I can make it to a year with all of em.

[winfred]

probably wouldn't last long with the shock load, maybe long enough to screw up the mounting point on the body


i was thinking more along the lines of SKF.

[Bill R.]

set in and really break something.



probably wouldn't last long with the shock load, maybe long enough to screw up the mounting point on the body

[peks]

wasnt bruno offering to make/sell some thrust arms with a roller bearing in place of the thrust are bushing a while back? seems like that would probably just shift the damage to something not so easily replaced. anyone remember that?

[rob101]

probably wouldn't last long with the shock load, maybe long enough to screw up the mounting point on the body
yeah i would be more worried about the mounting that the bearing, i've seen some road cars with sphericals. such as a low volume road car built in toowoomba this one (http://www.skelta.com.au/Home.htm) i'd highly doubt that a spherical that size would have any trouble
let me put it this way i looked at the sphericals at skf, one with an outer race diameter of 35 mm can withstand 41.5kN or 4.2 tonnes force of dynamic load. i am guess the size you'd look at would be closer to 40 mm diameter? there is no way in hell that a thrust arm will see accelerations higher than 1.5g from braking since a 5er weighs about 1700 kg that would be 2.55 tonnes of force. not to mention that their dynamic capacity would probably already have a safety factor on it so i guess the question is, how big is the external diameter of the bush?

[Anton CH.]

Why don't you have the m5 bushings pressed into the Hamburg arms? It will still be cheaper than buying the real thing. I actually always wanted to perform a uniaxial tensile strengt test or something on lemford and Hamburg parts to see how their quality stacks up.

[winfred]

i am thinking more along the lines of potholes and other sudden impact type events that are unavoidable in street use, the bushing may be designed to take that kind of force but the mount on the car would never survive, it wasn't designed with a solid bushing in mind, catching a pothole under braking probably gets into the 5-10 ton range or more


yeah i would be more worried about the mounting that the bearing, i've seen some road cars with sphericals. such as a low volume road car built in toowoomba this one (http://www.skelta.com.au/Home.htm) i'd highly doubt that a spherical that size would have any trouble
let me put it this way i looked at the sphericals at skf, one with an outer race diameter of 35 mm can withstand 41.5kN or 4.2 tonnes force of dynamic load. i am guess the size you'd look at would be closer to 40 mm diameter? there is no way in hell that a thrust arm will see accelerations higher than 1.5g from braking since a 5er weighs about 1700 kg that would be 2.55 tonnes of force. not to mention that their dynamic capacity would probably already have a safety factor on it so i guess the question is, how big is the external diameter of the bush?

[winfred]

i think the hamburg ball joint is total **** too from reading the complaints, the actual arm is probably fine as it's just a chunk of steel as long as it's to the proper dimentions


Why don't you have the m5 bushings pressed into the Hamburg arms? It will still be cheaper than buying the real thing. I actually always wanted to perform a uniaxial tensile strengt test or something on lemford and Hamburg parts to see how their quality stacks up.

[rob101]

i am thinking more along the lines of potholes and other sudden impact type events that are unavoidable in street use, the bushing may be designed to take that kind of force but the mount on the car would never survive, it wasn't designed with a solid bushing in mind, catching a pothole under braking probably gets into the 5-10 ton range or more
yes but the strut will see the majority of that loading i thought, thrust arm would see more braking and some lateral loading. But i agree with you that the mounting would be the weak point, my point was only that the bearing would last. I probably wouldn't do it anyway, think of the road vibration that would be transmitted... no thanks

[winfred]

no the thrust arm takes that hit for the strut, if you think about the design of the suspension and how it's braced and the direction that the majority of the force is coming from, when the wheel hits something the thrust arm knows about it before the rest of the suspension


yes but the strut will see the majority of that loading i thought,

[Kalevera]

Haaah...How many times do we have to write about this stuff before people stop being cheap and use good quality parts?

As Winfred said...it's not the bushing that's questionable, it's the ball joint. After all, the bushings are replaceable. The ball joints, in theory, aren't.

My FCP stuff looks like garbage after sitting outside all winter. Haven't stuck a pair of pliers on the joints yet to see if they're still good.

best, whit

[rob101]

no the thrust arm takes that hit for the strut, if you think about the design of the suspension and how it's braced and the direction that the majority of the force is coming from, when the wheel hits something the thrust arm knows about it before the rest of the suspension
yeah i don't know about that, i am assuming you are talking a vertical force, which is the maximum force you'll see in the suspension.

so the thrust arm rotates up down in an arc, ie at the ball joint end it is free to move up and down, ergo it would take very little force, but a braking force it is constrained thus it is loaded in tension. and to a small degree in lateral force. you can't have a load transmitted to a component that is free to move in that direction. generally speaking all suspension arms are designed to be primarily loaded in tension and compression not in bending.

it will however see a longitudinal load when the wheel is pushed forward/backward by the pothole or is that what you mean when you say 9-10 ton? (imperial ton that is right?) The other thing is, what i quoted there was the dynamic load, ie the max load permissible before the fatigue mode of failure is possible. the ultimate breaking strength was much higher and was at least a factor of 10 bigger.

just so that you know i am not disagreeing with you because i am some random guy, i did suspension design and modelling as my thesis for my bachelor of mechanical eng and its a subject i like discussing (now that i don't have deadlines for it lol):D

[632 Regal]

might have an issue with the balljoints but the shimmy is a bushing deal... the bushings look good but are like mush, I figured the 750's would at least give me 2-3 years like the Lemforders but... comparing the 750 bushings from BMA and the FCP ones they are not the same manufacturer.

and what would cause even the FCP ones to fail this quick if they were torqued correctly?

I dont get it. Ill look into having bushes pressed into the Lem arms and see what goes from there.


Haaah...How many times do we have to write about this stuff before people stop being cheap and use good quality parts?

As Winfred said...it's not the bushing that's questionable, it's the ball joint. After all, the bushings are replaceable. The ball joints, in theory, aren't.

My FCP stuff looks like garbage after sitting outside all winter. Haven't stuck a pair of pliers on the joints yet to see if they're still good.

best, whit

[BigKriss]

I'm running some spherical bearings in the thust arms for 2 months now. The bearing in my arms seems very sturdy. The disadvantage is not the road noise - but the feel of bumps transmitted though the chassis. Its a least 20% worse in terms of comfort (its hard for me to quantify). Sure the handling is really good, but crappy roads suck. As for the mounting point on the bearing - it looks okay so far.


yes but the strut will see the majority of that loading i thought, thrust arm would see more braking and some lateral loading. But i agree with you that the mounting would be the weak point, my point was only that the bearing would last. I probably wouldn't do it anyway, think of the road vibration that would be transmitted... no thanks

[rob101]

I'm running some spherical bearings in the thust arms for 2 months now. The bearing in my arms seems very sturdy. The disadvantage is not the road noise - but the feel of bumps transmitted though the chassis. Its a least 20% worse in terms of comfort (its hard for me to quantify). Sure the handling is really good, but crappy roads suck. As for the mounting point on the bearing - it looks okay so far.
actually dude i've been meaning to ask you, is that sway bar link just a hex bar, gundrilled, tapped at both ends with the rod ends put it, hell i could have done that for you!

[DanDombrowski]

Jeff,

When I first got my car, I was told I needed new thrust arm bushings, so I bought some. Little did I know I needed a press to put them in. I have them sitting here, you know of a way I can press them in? Mabye I'll just send em up your way for a few beans.

[ajt3nc]

Are Vines kits better than fcp? I wish BMA would put a kit together and I would jump on it.
My FCP kit was installed 10/05 and I run at least 800 miles a week. It is still okay. I actually used a torque wrench installing it and 2 days later.
The tires ( replaced michelin 225/60s with a generic 205/65 ) made a bigger diff than the thrust arms.
My personal, uninformed, opinion is everyone who gets a shimmy reads the forum and diagnoses a thrust arm, ignoring tires,brakes,rotors,alignment and balance.

[632 Regal]

you have little FCP/Hamburg angles on your side....dont question it. They shou;d work as yours in all applications but obviously dont.

for the cost I was full behind these but 3-4 months? I dont drive hard at all, been very placent on shitty roads. what do you do with defective? eat it....case closed.

The manufacture dont know, the distributer dont know...know one knows, so the same shitty parts keep being distributed.

FCP aint gonna listen to me since he makes 100k+ a year just distributing **** that other people are gonna buy for the savings. ..see the circle?

[genphreak]

you have little FCP/Hamburg angles on your side....dont question it. They shou;d work as yours in all applications but obviously dont.

for the cost I was full behind these but 3-4 months? I dont drive hard at all, been very placent on shitty roads. what do you do with defective? eat it....case closed.

The manufacture dont know, the distributor dont know...know one knows, so the same shitty parts keep being distributed.

FCP aint gonna listen to me since he makes 100k+ a year just distributing **** that other people are gonna buy for the savings. ..see the circle?Jeff, just swap the bushings (the grunts (http://gruntsbushings.com) ones are awesome I can tell you) and then keep an eye on your bjs, since the bushings are the primary weak point. After all this is where something that looks as good can in use work out to be crappier. They could come from anywhere and I'd expect some dude to be making green ones out of rubbishy material.

Thing is Hamburg technik are not the only 'brand' of cheap arms, a lot of 'EU sourced, TUV approved' arms are out there. I think Meyle even make them, surely Lems can't be the only good ones- but perhaps so, as they are the only OEM ones (is this right or do Meyle or others ever get a look in supplying these parts?).

Whit is right perhaps that the bjs could be poor, but we need the hard data to know how much poorer, prehaps his experience is not based on a large sample yet.

Hopefully he'll say so if he disagrees- unless he's too damned tired of this wretched topic, even I am! Good luck under there... :) Nick

[632 Regal]

M5 bushings?


Jeff,

When I first got my car, I was told I needed new thrust arm bushings, so I bought some. Little did I know I needed a press to put them in. I have them sitting here, you know of a way I can press them in? Mabye I'll just send em up your way for a few beans.

[DanDombrowski]

750i

[632 Regal]

let me see if I can check the BJ ends in the lemforders, if good I'll be interested (now to figure out how to check em)

[winfred]

31 12 2 226 528 i like em better then the 750s and they are still air gap bushings so you don't have the noise transfer of solid


M5 bushings?

[MBXB]

Don

Gale made a press so you can extract and install the bushing in place.

http://www.nmia.com/~dgnrg/page_26.htm



Jeff,

When I first got my car, I was told I needed new thrust arm bushings, so I bought some. Little did I know I needed a press to put them in. I have them sitting here, you know of a way I can press them in? Mabye I'll just send em up your way for a few beans.

[MBXB]

Peks,

Bruno also had those urethane inserts, which I currently have on my thrust arms. They are molded to sandwich the OEM/750/M5 rubber. Last I heard, he was looking for a shop to fabricate another batch.


wasnt bruno offering to make/sell some thrust arms with a roller bearing in place of the thrust are bushing a while back? seems like that would probably just shift the damage to something not so easily replaced. anyone remember that?

[rob101]

Don

Gale made a press so you can extract and install the bushing in place.

http://www.nmia.com/~dgnrg/page_26.htm
Ho-made press?
thats pretty good! i especially like the use of the porsche 356A
but we have 3 presses at work one of them is 100 ton :D and i am not even a mechanic;)

[Dizzy]

My FCP Hamburg test results are in....

I have almost 10k miles on my FCP thrust arms and the busings are giving the 55-65 shake!!! woohoo look at all the money I saved and the fun I had, cant wait to do this all over again in less than a few months.

AMEN for cheap parts, if not for that what fun would I have! This is with their self proclaimed 750 bushings too.

I think I'll join in the group buy and get a few sets, maybe I can make it to a year with all of em.
Oh man, hate to hear the bad news. I had to do mine about a year ago. I've been burned a few times myself . I finally got my starter prob fixed. It was the second add on alarm. take it easy