FRONT SRING PERCH BOLTS

[2old2fast]

AT about 20K miles a spring perch bolt on my spring behind frt end sheared! these perch bolts came from speedway and appeared to be nicely tig welded. so... I ground off the broken bolt head and stick welded a new grade 8 bolt on, did the other side for good measure. that was about 8000 miles ago. my question is: is this a common problem [breaking bolt]? Does anyone have a recomendation as to how often these bolts should be checked/replaced? just curious, dave

 

[Youngster]

I suspect what happened was when the spring retainer was installed, that was the first bolt tightened. These bolts should be tightened in a cris cross pattern so this type of failure dosen't happen. JMO

Ron

 

[2old2fast]

seems I didn't use the right terminology. I'm reffering to the bolt that goes from the shackle to the batwing,i.e. small tube w/bolt welded to the side. sorry for any confusion. dave just looked at catalog ...called a spring pivot

again,I apologize

 

[ellis8500]

Unfortunately, many of the fasteners now come from China and they are not always what they are supposed to be. Bolts marked as grade 8 may not even be up to grade 5 or grade 2 specs. And, there is no way to tell unless you have them tested. It's been a problem now for years. Even the best suppliers are sometimes affected.

 

[one finger john]

Could you post a picture?

 

[Ted Brown]

Was that a 1/2" or a 5/8" bolt? and how soft is your front spring? I have heard of bolts breaking when using heavy springs, like trailer springs, one trailer spring is usually strong enough to hold up your whole car... That can be a shock to those front spring hangers. Always keep an eye on them to make sure they are not lose.. Another thing, that is the reason that I cut the tube down shorter to allow for back and forth movement, when the frame moves up and down, the shorter the radius rods, the more that movement comes into play, that is a very tight bind sideways... Ride safe :hoist:

 

[2old2fast]

BOLT SIZE WAS 1/2". HAVEN'T FIGURED OUT HOW TO POST PICTURES. STILL TYPE "KEY" W / 1 FINGER! DAVE

 

[one finger john]

BOLT SIZE WAS 1/2". HAVEN'T FIGURED OUT HOW TO POST PICTURES. STILL TYPE "KEY" W / 1 FINGER! DAVE

LOL Maybe someone has fiquered out how my name came about. "One finger John" is in reference to my typing abilities, not one finger salutes or gestures. So it was a perch assembly that broke? Doesn't some one make forged, one piece perch assemblies? I thought RPM did.

I haven't fiquered out how to post pictures either, John

 

[one finger john]

You are referring to the spring perch mounts at the end of the springs that attach the spring to the bat wings ? Not the spring perch in the center of the front cross member. Right ?

I'm so confused, John

 

[Keeper]

Pretty sure he is talking about this:


This was discussed on the old site as well. Not exactly sure what came out of it.

 

[putz]

Dave or one finger if you need pics posted you can email them to me and I will get them posted My email jdkelly@pctcnet.net
Putz

 

[2old2fast]

that's the offender! dave

 

[one finger john]

Ah, Keeper to the rescue! Thank You. And thank you to PUTZ for the offer to short stop and relay pictures. My younger brother is the IT engineer with a local BMW dealership and I have asked him for help, but he keeps insisting that he works with PCs and I have a MAC and never the twain shall meet. Funny, his personel phone is an Iphone. Is he telling me something?

Anyway, if that is the part that broke the connecting bolt (transverse or longitudinal, the bolt that goes into the spring eye or into the batwing), I would look for the strongest, forged from unobtaineum, replacement I could. And replace BOTH pieces, left and right. and use real, American made grade 8 bolts. If they break then it really does become a "suicide front end".

Here come the questions ... whose manufacture is the front end, how old is it, has it been lubricated properly, is it exposed to the elements when not in use, what are the elements it is exposed to (road salt, sea air, constant moisture, etc.), did it sit for long periods of time (again, exposed to the elements), are the roads it travels on considered "rough". As for welding a new bolt in place of the broken one ... not questioning your welding ability ... I would look for brand new parts to replace the ones that have or might fail. If one side fails then the other side will also. And don't get me started about Chinese wheel bearings.

As Ted would say, Ride Safe, and let us know how you fare, John

 

[2old2fast]

in the picture that keeper posted, that appears to be a 1 p iece unit [forged]? mine came from speedy bill and was a tube w/bolt welded to the side, basically same configuration as old CP plan['96] had been on the road around 7 yrs. [20 K MILES] bought axle bare from speedy bill as well as spring, shackles, and the offending pieces . fabbed the rest myself based roughly on TPplans. never was out in bad weather, no salt spray in north central ill. [just crooked politicians giggle] roads are actually pretty good. and just to be clear, it was the stud [bolt] that attaches the shackle tothe batwing[transverse] that broke and I did replace both sides. now my finger's tired lol dave

 

[Northstar T]

I'm still waiting to hear the story of what happened at the time the part broke. I'll bet it was exciting to say the least.

Russ

 

[Old Rotor Flap]

The picture Keeper posted is most likely a casting rather than a forging.

If it were a forging, the ads would say so as forgings cost considerably more than castings. If it doesn't say forged, assume it's a casting. These days, some casting methods are termed forgings possibly because the proper terms got translated during their casual trip across the Pacific.

In airplane drawing class we learned; No castings and No weldments. Having said that, there are a lot of castings in helicopters and some weldments in smaller aircraft.
But those vehichles are very fragile compared to cars.

Regardless if it's iron, steel or stainless, if it's a casting. I would not use it in a suspension application. That goes for axles, spindles, batwings and shock, spring mounts and spring perches.

In the case of the spring mount, overtightening of a casting could have contributed to the failure.