BMR track pack tq arm breaks (street driving) takes rest of drivetrain with it (Pics)
#42
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From: NW Houston, TX
Originally Posted by davered00ss
So BMR took no responsibility for this? WTF!
#44
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Originally Posted by davered00ss
Not to self..............Do not buy BMR TQ arm.
First.... anyone who modifies a car...... places/installs high performance parts and doesn't back check those parts on a regular bassis needs to buy a Civic and be done w/the regular maintenance that's REQUIRED when driving/owning a hotrod.
High permormance/race parts break. Get used to it or get back in the Civic.
I bought a BMR adjustable TA. I saw the 4 holes. I took it upon myself to eliminate the potential risk by welding a 1/4" plate to both sides of the arm mount bracket and drilling the 2 holes for the end links to bolt up.
Problem solved. The Moser will scatter before the TA.
EDIT: I also saw the "disclaimer" on BMR's site.
#46
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From: Lakeland, FL
Originally Posted by Jammer
Sorry to hear it Mike! I just bought # 2 as well. Gotta have a few extra cars in stock when ya make power.
J
J
#48
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From: Lakeland, FL
Originally Posted by LowETz
Note to self.......... stupid is as stupid does.
First.... anyone who modifies a car...... places/installs high performance parts and doesn't back check those parts on a regular bassis needs to buy a Civic and be done w/the regular maintenance that's REQUIRED when driving/owning a hotrod.
High permormance/race parts break. Get used to it or get back in the Civic.
I bought a BMR adjustable TA. I saw the 4 holes. I took it upon myself to eliminate the potential risk by welding a 1/4" plate to both sides of the arm mount bracket and drilling the 2 holes for the end links to bolt up.
Problem solved. The Moser will scatter before the TA.
EDIT: I also saw the "disclaimer" on BMR's site.
First.... anyone who modifies a car...... places/installs high performance parts and doesn't back check those parts on a regular bassis needs to buy a Civic and be done w/the regular maintenance that's REQUIRED when driving/owning a hotrod.
High permormance/race parts break. Get used to it or get back in the Civic.
I bought a BMR adjustable TA. I saw the 4 holes. I took it upon myself to eliminate the potential risk by welding a 1/4" plate to both sides of the arm mount bracket and drilling the 2 holes for the end links to bolt up.
Problem solved. The Moser will scatter before the TA.
EDIT: I also saw the "disclaimer" on BMR's site.
I never saw the disclaimer to be honest, I had tightened the bolts once although they were not loose just had 1 missing which I though was the installers fault, I hear what you are saying about checking everything but honestly I drove the car 1 time a week on the interstate to work and back and thats it, no racing etc I really did not think there was enough stress to do anything especially since I had regular street tires on.
Now I know about this problem and I will be checking the bolts regularly, mabye a sticky should be made at the top stating that if you have a moser make sure to check the tq arm bolts regularly.
no need to be an *******, but then you probably check every bolt on your car weekly so this comes as a shock to you.
#49
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You guys stop beating up on my friend Mike K. I did not know any of this either. If I had my SS still the same thing would have happened to me. Some things are not just common knowledge. Do you go around and tighten up every bolt on your car? It has to loosen up over time.
#50
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From: Ontario, Canada
I feel really badly for the guy with the broken car. Everyone should learn from this example. For anyone with aftermarket parts on their car you should keep in mind that the aftermarket fabricators have no standards to meet. Be very careful about modifying critical items on your car.
The OEMs have to certify cars to meet certain standards, in particular suspension pices must meet endurance standards. The aftermarket guys cannot actually tell you its safe to use these pieces on a public road. There are 2 reasons for this, the aftermarket guys do not have the expertise nor have they had the parts certified as a form fit function replacement for the stock parts.
The scariest parts are the tubular K members, GM has no incentive to make this part heavy, quite the opposite. So why does some fabricator with a welding jig think their light weight version is safe? They actually do not know. They just say "race only" and they are covered.
If you look at the first post in this thread you can see "beach" marks on one of the broken pieces. The part failed in fatigue. It may have been a flaw in the material that grew until failure. It may have been over stressed due to poor design and grew on its own (no measurable initial flaw). It may have been that load pathes changed as these famous bolts backed off their preload because of the design of an unrelated part, which then grew until failure.
I am not slamming a particular vendor but people are way too quick to dismiss the OEM parts as the crappy result of serious cost cutting and weight reduction yet most OEM suspensions stay together nearly forever.
If enough people break aftermarket suspension pieces insurance companies will become "aware" of this industry. Regulation will soon follow and most of these products will disappear.
The OEMs have to certify cars to meet certain standards, in particular suspension pices must meet endurance standards. The aftermarket guys cannot actually tell you its safe to use these pieces on a public road. There are 2 reasons for this, the aftermarket guys do not have the expertise nor have they had the parts certified as a form fit function replacement for the stock parts.
The scariest parts are the tubular K members, GM has no incentive to make this part heavy, quite the opposite. So why does some fabricator with a welding jig think their light weight version is safe? They actually do not know. They just say "race only" and they are covered.
If you look at the first post in this thread you can see "beach" marks on one of the broken pieces. The part failed in fatigue. It may have been a flaw in the material that grew until failure. It may have been over stressed due to poor design and grew on its own (no measurable initial flaw). It may have been that load pathes changed as these famous bolts backed off their preload because of the design of an unrelated part, which then grew until failure.
I am not slamming a particular vendor but people are way too quick to dismiss the OEM parts as the crappy result of serious cost cutting and weight reduction yet most OEM suspensions stay together nearly forever.
If enough people break aftermarket suspension pieces insurance companies will become "aware" of this industry. Regulation will soon follow and most of these products will disappear.
#51
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From: Ontario, Canada
By the way, for anyone interested in keeping those bolts from backing out the process is straighforward. Head bolts never back off because the bolt is slim and stretchy compared to the metal pieces its holding together. The ultimate example is the torque to yield fasteners. Why does this matter?
When you tug on a head the loads in the bolt change only a little since the "joint" is much stiffer than the bolts. On this arm the load in the bolts changes a lot since there is only a thin metal plate making up the joint. Flex the joint enough and the bolts lose all the preload under some conditions.
Use longer bolts and instead of a thin washer, use a metal cylinder (a very short pipe with very thick walls) like you attached maybe 30 washers together. That will greatly reduce the likely hood of the bolt backing off. Loctite is good for what it is but it cannot change the way the joint carries loads.
When you tug on a head the loads in the bolt change only a little since the "joint" is much stiffer than the bolts. On this arm the load in the bolts changes a lot since there is only a thin metal plate making up the joint. Flex the joint enough and the bolts lose all the preload under some conditions.
Use longer bolts and instead of a thin washer, use a metal cylinder (a very short pipe with very thick walls) like you attached maybe 30 washers together. That will greatly reduce the likely hood of the bolt backing off. Loctite is good for what it is but it cannot change the way the joint carries loads.
#52
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Originally Posted by Mike K.
I never saw the disclaimer to be honest, I had tightened the bolts once although they were not loose just had 1 missing which I though was the installers fault, I hear what you are saying about checking everything but honestly I drove the car 1 time a week on the interstate to work and back and thats it, no racing etc I really did not think there was enough stress to do anything especially since I had regular street tires on.
Now I know about this problem and I will be checking the bolts regularly, mabye a sticky should be made at the top stating that if you have a moser make sure to check the tq arm bolts regularly.
no need to be an *******, but then you probably check every bolt on your car weekly so this comes as a shock to you.
Now I know about this problem and I will be checking the bolts regularly, mabye a sticky should be made at the top stating that if you have a moser make sure to check the tq arm bolts regularly.
no need to be an *******, but then you probably check every bolt on your car weekly so this comes as a shock to you.
Not to self..............Do not buy BMR TQ arm.
Sorry if there was any confusion as to who I was kicking. As far as checking every bolt on my car..... not every day, but I do take a quick look at most everything on a regular bassis..... and yes.... I am **** when it comes to my cars/trucks.
Btw, FWIW..... the bolts supplied are short. Two of the holes(front/top-bottom)go all the way through the housing. The rear/top-bottom are blind but will accept a longer bolt. After checking bolt hole depth, I found there was only ~ 5/8" of bolt threaded into the hole after the bracket thickness(1/4") + washer(1/8") using the short bolts. Could be wrong, but felt like that was a lil' on the shallow side for the loads they were taking. I bought some longer bolts(2)1-1/2", and (2)1-3/4" grade 8.
Between the extra plates I welded to the bracket, the longer bolts and little red loctite, I dare the bolts to back out.
If it ever continued to be an issue, I'd tack a spot weld on the side of each bolt head.... and if the TA needs to be removed, just cut the tack weld w/a ziz wheel or the die grinder....
Peace-
Last edited by LowETz; 11-02-2005 at 12:24 PM.
#53
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same thing happened to me when i had my 12 bolt..... it broke in the same place....my bolts kept coming loose..... once i got my 9 inch installed..... i couldnt be happier with my bmr stuff.... it has done nothin but give me incredible 60 foots....... 1.47 on a bfg drag radial.... for an 11.0 car... it hink thats pretty good...... but that sux it happened.... but its deff fromt eh 12 bolt..... i broke about 4 torque arms when i had my 12 bolt.... only 2 of them were bmr.... and it was b/c of that.....nothin has broke since my 9 inch though
#54
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I lost one of the long "through" bolts out of my Moser 9 inch with Addco torque arm, so be warned, it can happen with those too. Luckily there was no carnage except the missing bolt which had to be replaced. I traced the cause to two things: the stock TA bolts are a little on the short side to go through the thick mount on an aftermarket TA. The other thing is, ny-lock nuts don't lock well after they have been used a couple times. BTW, my TA mount has the same set of double holes as the BMR unit pictured. I think it would be a good idea to weld up the set of holes you are not going to use. And if I suffered this kind of carnage, I would probably tack-weld the bolts in the next time; in fact, maybe I will do that anyway.
#56
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From: Lakeland, FL
hmm welding may not be such a bad idea, I am hoping just the tail housing is busted but the only thing that worries me is that I had to hammer out the yoke with a chisel and hammer which makes me think the output shaft may also be messed up.
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From: Eagle Pass, TX
Originally Posted by Mike K.
hmm welding may not be such a bad idea, I am hoping just the tail housing is busted but the only thing that worries me is that I had to hammer out the yoke with a chisel and hammer which makes me think the output shaft may also be messed up.
Maybe you got lucky and it didn't bend, but just in case...start pricing that output shaft of yours.
#58
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From: Lakeland, FL
Originally Posted by PERFECT Z28
I also had to take the BFH to get my yolk out...and wouldn't you know it, after replacing everything that "appeared broke" and buying all of the relocation stuff, I still had a vibration that started to get worse the more I drove the car. Point is, my last alternative was to check the output shaft...turned out the output shaft was bent.
Maybe you got lucky and it didn't bend, but just in case...start pricing that output shaft of yours.
Maybe you got lucky and it didn't bend, but just in case...start pricing that output shaft of yours.
Good call, I am thinking it probably is bent cause if not then why should I have to use BFH mod to get you yoke? You cracked your tranny also? same tq arm issue?
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From: Albuquerque NM - The Land of 8000ft DA
Here is your smoking gun.
Looks like it cracked right along the ridge of the bolt hole and slowly propagated. You can tell from the "beach marks".
The crack probably formed awhile ago and it just took time for the part to fail.
Any metallurgical engineers on here? They can probably explain it better than I can.
I would provide some better info but I left my materials textbook at work.
Frank
Looks like it cracked right along the ridge of the bolt hole and slowly propagated. You can tell from the "beach marks".
The crack probably formed awhile ago and it just took time for the part to fail.
Any metallurgical engineers on here? They can probably explain it better than I can.
I would provide some better info but I left my materials textbook at work.
Frank
#60
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Damn, sorry to hear that. I didn't know about the bolts backing out and causing major damage until I posted on here that my bolts were coming loose, and one was even missing last time I checked. I am trying to find replacement ones as we speak. I dont think hardware stores will have them, but I will still check. I will be trying red locktite and tighten them down real real hard. My bottom ones were backing out, so I used a breaker bar to tighten them, and honestly used almost all the power I had in me even with the breaker bar, and they have not came loose yet. I can't get a breaker bar to the top ones though.
BTW, anyone know of a place online that sells bolts to use with a Moser 12 bolt? I have had a hard time finding grade 8 or hardened bolts from the local hardware stores in the past.
BTW, anyone know of a place online that sells bolts to use with a Moser 12 bolt? I have had a hard time finding grade 8 or hardened bolts from the local hardware stores in the past.