Help - Grease able Pivot Shafts

-

carfreak6970

Well-Known Member
Joined
Jul 25, 2014
Messages
552
Reaction score
203
Location
Pittsburgh
So I recently purchased greaseable pivot shafts for a 67 Big block dart (from a reputable company). I had the bushings installed in the lower control arms with the pivot shafts and this past weekend I went to install them. Only to see that the shafts fail when I torqued them to 90 ft-lbs. The 67 dodge service manual says the pivot shaft nuts are supposed to be torqued to 130 ft-lbs. The kit I received did not have any installation instructions and I could not find any information regarding installation on the company's website. I am still waiting to hear back from the inquiry I sent them yesterday.

Has anyone used these with any success? What did you torque the nuts too? I was talking to a sales rep and they told me to torque them to 60 ft-lbs. For an application such as this, I feel like that is way to low.

But if they are only to be torqued to 60 ft-lbs, I have a major concern (since the ones I have broke at 90 ft-lbs and the service manual says torque to 130 ft-lbs) that the greaseable pivot shafts are much weaker than the OEM parts. So has anyone been running these on there cars and not had problems with them?

Thank you in advance for your advice/help
 
Umm...from what company did you get these shafts? I just want to be sure to avoid them.

When I get back from my vacation next week, I hope to start my suspension rebuild. Or it might have to wait until May.
 
These are from Hotchkis Sport Suspension (item # 3005). Which I was under the impression they were a reputable company. But below are some of the pictures I took of the shafts.

View attachment image8-2.jpg

This is comparing the old shaft to the new one. The shaft in the bottom picture is my original one where as the one on the top is the replacement. You can see the grease able shafte is a little shorter on the left end that gets placed in the bushing (however the OEM one has that metal sleeve which makes it a little longer, so I dont think that this area is of concern). But on the right you can see that the shaft is tapered a little differently closer to the flange. As for the threaded end, I do know if that was elongated due to the shaft stretching during torquing.

View attachment image8-4.jpg

This shows the shaft side of the failure. As you can see it was a ductile failure instead of a brittle failure (which is probably a good thing).

View attachment image8-3.jpg

This image shows the threaded side of the failure. You can see the material surface a little better here. But the breakage has me wondering what high strength steel they are using.

So has anyone used grease-able shafts with success? Should I just stick with my OEM ones? Anyone use the OEM shafts with urethane bushings?
 
Are those hardened? Pretty crazy snapping a 5/8" shaft like that unless it was hardened. The black look to them makes me think they went through a hardening process.

The stock ones are not hardened.

On the upside if there was a failure after the fact, the control arm has no where to go so your lca isn't going to fall off but I still wouldn't want those breaking off!
 
Here is what I don't understand. What holds the control arm onto the shaft? I hope they are not depending on the torsion bar to do it because it does not. This is the same problem with the poly kits.

Using them this way is not to sturdy. It does not hold the arm from floating front to rear At the bushing. The torsion bar can nott be used to to this because they are designed to float in the hex ends.

That is why there is space at the rear where the clips go on. The factory rubber bushin is what holds the arm in place .
 
Are those hardened? Pretty crazy snapping a 5/8" shaft like that unless it was hardened. The black look to them makes me think they went through a hardening process.

The stock ones are not hardened.

On the upside if there was a failure after the fact, the control arm has no where to go so your lca isn't going to fall off but I still wouldn't want those breaking off!

I dont believe they were hardened. usually when you harden a material it becomes brittle. If a hardened rod failed in this manner the area would be "necked" down, or reduced diameter, at the breakage area. This did not happen. this was more of a spiral break which leads itself to be a ductile break.

Here is what I don't understand. What holds the control arm onto the shaft? I hope they are not depending on the torsion bar to do it because it does not. This is the same problem with the poly kits.

Using them this way is not to sturdy. It does not hold the arm from floating front to rear At the bushing. The torsion bar can nott be used to to this because they are designed to float in the hex ends.

That is why there is space at the rear where the clips go on. The factory rubber bushin is what holds the arm in place .

I was concerned with this too. But after reading another thread here, I believe the struts now have more of the responsibility of holding/locating the lower control arm
 
the rusted area looks as it started there at the bottom of the thread cut , could be the site of the break prior to the install . how is the other one ? and i don't think that cut threads will torque to 130 , though only rolled threads would handle that at that rate of torque . did you ask hemidenny what his unit uses ?
 
It looks like you ran out of thread? Was there a washer between the nut & the K frame?
 
After the first one broke, I didnt bother putting on the second one. And that actually isn't rust (if we are referring to the second picture I posted), that is the area that was hit with a brass hammer to remove from the Lower control arm assembly from the K-frame.

It does appear like I did, but I think the pivot shaft did stretch to the point that the all the threads ended up in the nut before it broke off. But Yes there was a washer between the nut & K-frame.
 
In vehicles that got little to no maintenance, The tapered holes in the K members got wollered out. If the taper doesn't fit and stop the shaft from letting all the threads out the nutted side.... you would run out of threads. Seems I remember another issue with the quality of the nuts provided too. Threads stripped out ?
As for someone elses "what holds the lower arms in place" question... From what I've read, adjustable strut rods are required to draw and hold the lower arms position.
 
wow - this is rough.. that failed at 90 ft lb!? I do know that when using poly your torque #'s will change quite a bit - do the shafts have the OEM style stop pin or are the nuts the ny-lock type?
 
I to just went to torque down my Hotchkis grease able pins and the nut w/thick washer under has stripped out. I am now wondering if I ran out of thread? ,Now I have to get this p.o.s off that only wants to spin in position GerRRRRR!!!!
 
wow - this is rough.. that failed at 90 ft lb!? I do know that when using poly your torque #'s will change quite a bit - do the shafts have the OEM style stop pin or are the nuts the ny-lock type?

Mine are a crimped type lock nut.
I feel your pain car freak I wish mine broke off as Now I have to get this dam nut off and figure out what to do next.
 
I am a huge fan of ny-lock nuts.. I always get them for whatever I am doing. It amazes me that these things don't come with instructions.. I am looking at the web-site and don't even see them there.. WTH? - am I missing them or...?
 
Regarding my previous post. I have poly bushings on my Duster. Lower arms only. The struts hold the arm out at the wheel. When I put my car up against the roll control to heat the tires my fornt wheels move . The control arm slides front on the bushing which is lubed . When I back up and hit the brakes. it pushes the torsion bar back against the clip that holds it in. Who ever thought up these bushings and the way they are secured wasn't thinking. The sleeves should be secured to the bushing as the factory bushings are.

And who ever thought of the greasable shafts had to be a real idiot. Common sence will tell you they cannot keep the control arm secured. The reason when the lower bushing rips on a factory set that they need to be replaced is what you all are replacing them with . A set up that is no good before you install them..

If these are used without the torsion bars but with coil overs and fasten the shafts some how through the torsion bar hexes they may work. But not with the bars in place. Something has to hold the arm front and its not the stut at the other end of the LCA.

By looking at the break the metal is poor quality and then they drill a hole up the center for grease. That wasn't to smart. But guess what? You guys are buying them so who's the dummy
 
I chkd website out (on my phone) and dont see instructions. I see MDS lol.
60 ft lbs to me seems awful light.
Have you talked/emailed Hotchkiss?
 
I wouldn't worry about them. Keep them in your tool box and use them for a drift pin. Put the factory bushing in and don't tighten them until the car is setting at ride height. If you do that they will last a long time. Remember MOOG or they will dry up in a month.

Don't go to Auto Zone or Advances. NAPA and ask for MOOG
 
I have not talked to Hochkis and I don't think I'd get to far to short of a fuse.
I just removed the other side before torquing it down and look there no threads stick out of the k frame, if I add the stock washer under the supplied one she draws right up. WTF!!! Boy If I could kick my own *** For not doing my homework!! And now old man Mopar makes some good points, what to do what to do????
 
screw those things - get MOOG and move on.. poly or OEM type is up to you..
I have not talked to Hochkis and I don't think I'd get to far to short of a fuse.
I just removed the other side before torquing it down and look there no threads stick out of the k frame, if I add the stock washer under the supplied one she draws right up. WTF!!! Boy If I could kick my own *** For not doing my homework!! And now old man Mopar makes some good points, what to do what to do????
 
I would contact Hotchkis and see what they say. They are a reputable company and know that they will stand behind their product.

Thanks
James
 
It looks like you ran out of thread? Was there a washer between the nut & the K frame?

This. The appears the fractured pin ran out of threads. Whether that's a design flaw with the length of the pin or a problem with the K member I'm not sure, but based on where it fractured that's what happened.

As far as the torque specs go, I know that Firm Feel greaseable pivot pins get torqued to 100 ft/lbs. I have greaseable pivot pins on all of my cars, with tens of thousands of miles on them between them, and no issues whatsoever.

I would call Hotchkis. They ARE a reputable company. I have some of their parts on my Challenger, and all are well made. I did have an issue with the heim joints on my Hotchkis UCA's failing after about 7k miles, and after talking with Hotchkis they replaced all of them at no cost to me. I would definitely talk to Hotchkis. The manufacturing process is not 100% perfect, it could be that there was a metallurgic issue with the pin as well. And that could mean that there's a "batch" of pins with issues. If that's the case, Hotchkis needs to know about it.

Regarding my previous post. I have poly bushings on my Duster. Lower arms only. The struts hold the arm out at the wheel. When I put my car up against the roll control to heat the tires my fornt wheels move . The control arm slides front on the bushing which is lubed . When I back up and hit the brakes. it pushes the torsion bar back against the clip that holds it in. Who ever thought up these bushings and the way they are secured wasn't thinking. The sleeves should be secured to the bushing as the factory bushings are.

And who ever thought of the greasable shafts had to be a real idiot. Common sence will tell you they cannot keep the control arm secured. The reason when the lower bushing rips on a factory set that they need to be replaced is what you all are replacing them with . A set up that is no good before you install them..

If these are used without the torsion bars but with coil overs and fasten the shafts some how through the torsion bar hexes they may work. But not with the bars in place. Something has to hold the arm front and its not the stut at the other end of the LCA.

By looking at the break the metal is poor quality and then they drill a hole up the center for grease. That wasn't to smart. But guess what? You guys are buying them so who's the dummy

You're wrong. About all of it. This isn't the first time you've posted this, nor is it the first time I've responded.

The bonded rubber of the OE pivot pin bushings DOES NOT secure the LCA. No engineer worth his salt would create a design that required rubber bonding to keep a lower control arm from moving fore/aft. It's simply not designed for those kinds of loads, and is not capable of supporting those kinds of loads, period.

The torsion bar does keep the LCA from moving, but only within a range. The torsion bar can slide back and forth a bit in the socket, but even with the torsion bar all the way back the LCA can't come off of the pin. When the rubber bonding of the rubber LCA bushings fail, as it often does, it is in fact the torsion bar that keeps the LCA from falling off the car. I know this for a fact because I have seen LCA's fall off the pins after the torsion bar and strut rods are removed, because the stock LCA bushings were shot.

It is in fact the job of the strut rod to locate the LCA fore/aft. That is in fact it's only purpose, and the reason that they were included in the design of the suspension. They serve no other purpose. If the LCA was positively located by the LCA bushings, you wouldn't need the strut rod.

In the stock system, the strut rods are a generic length, and have a bit of play from the thick rubber bushings they use at the K frame. If installed properly, the rubber LCA bushings maintain their rubber bonding to the steel inserts, and between that bonding and the additional give in all of the rubber bushings the LCA is located within a range small enough for a decent alignment. It's not perfect, and if you think there's no play in the LCA fore/aft you're mistaken. If you removed the strut rod from the system, the rubber bonding would fail in short order and your LCA would travel fore/aft with the torsion bar, as much as the torsion bar can move in the socket.

When using a poly LCA bushing there are several changes. The poly insert isn't bonded to anything, although it should fit snugly to the pivot shaft and into the steel insert in the LCA, to the point that it should actually require a light press to install. If it doesn't, the stock shell is worn out or too large in its tolerances, or the bushing is undersize. This is actually the issue with the poly bushings. The stock steel inserts are not all the same size, and can be damaged when the rubber wears out and the pin starts moving around in the bushing. Because the fit of the poly bushing can vary, so does the ease with which the pin can move in and out of the K and LCA. The poly bushings also have less give in the material, which means when using them the LCA must be more accurately located. Since the stock strut rods were generic they are NOT a good choice when using poly bushings. Adjustable strut rods should be used to more accurately locate the LCA. This also solve the issue of the fore/aft movement on the poly bushings. Even with a light press, the LCA can move more easily against the poly bushing than with the rubber bonding of the originals. Using an adjustable strut rods solves this issue, as it eliminates the additional play of the rubber strut rod bushings and allows you to more accurately locate the LCA where it needs to be.

There is nothing really wrong the design of the poly bushings. They do depend on the tolerances of the steel bushing shells in the LCA, so they aren't the best solution out there anymore (BAC's Delrin bushings are much better). But that doesn't mean they won't work if you take the time to install them properly. And there is nothing wrong with the greaseable pins either (at least in general). I have had poly bushings, greaseable pins, and adjustable strut rods on my street driven cars for 10's of thousands of miles. I've had adjustable strut rods on my cars for over 80 thousand miles combined now. When properly installed, the LCA does not move fore/aft on the pivot pin or poly bushing. Given that I have less than a 1/2", and in some places less than a 1/4" of clearance between my tires and the hard parts on my cars (frame, fenders, braces, etc) I would know immediately if my LCA's moved much in any direction, as my tires would start rubbing on the body/frame of my car. That's true on my Challenger and my Duster.

Your LCA's move around on your car because your installation was incorrect in some way. The bushings might be too loose in the shells, or the strut rods are the wrong length, or the K frame mounts are worn out, but something isn't right. Poly bushings do not function the exact same way as the OE bushings did, and you can't expect them to. Other considerations have to be taken into account, and while they aren't mandatory adjustable strut rods should really be used with poly LCA bushings. Also, because the shape of the poly bushing is different, the shoulder on the LCA pivot pin should be different as well. It is different on most of the greaseable pivot pins because they were designed for use with the poly bushings. If you re-use the stock pivots, the shoulder on the pivot isn't quite right for the poly bushings. You wouldn't install a high lift cam in your engine without the proper valve springs or rocker gear, and by the same token you shouldn't expect the poly bushings to work as intended if you don't make some additional suspension upgrades.
 
Thank you all for your responses.

I did contact Hotchkis and they are going to send me new shafts at no cost to me (this happened Tuesday). Thats all fine and dandy, but seeing how that metal does look like it has metal issues, whats to say that new ones wont as well?

I asked them about the torque rating for these shafts and the sales guy had to go and ask. At which point an individual claimed the torque rating to be 60 ft-lbs. Any engineered product such as these should come with instructions, especially if the installation procedure or torque rating is different from OEM and be readily available.

Thank you 72blunblu for giving some reassurance that the design of grease able shafts do hold up in the driving environment. But with your explanation of how these are suppose to interact with the K-frame I guess if these would fail while driving, it shouldn't be a catastrophic failure if caught early. You should be able to bring the car under control and off to a safe place.
 
Glad they are stepping up. One thing I would do is email them to create a paper trail of the issues. Also ask them to email you install instructions. IF they fail again at least there's proof of previous issues.
Good luck!
 
It looks like the shaft is too long - if you look at where the threaded section starts on the new shaft versus the original shaft, it is off by quite a bit. Like others have said, you ran out of threads and the shaft broke.

I'm guessing that you got the B/E shafts by accident. It's possible that they were mis-labeled. This would explain the difference in length.

What's the overall length of the shaft that broke? Or, since it may have elongated - the shaft on the other side that didn't break? Can you post a side-by-side of the unbroken shaft and the original shaft, with the two of them lined up at the flange?
 
I'm guessing that you got the B/E shafts by accident. It's possible that they were mis-labeled. This would explain the difference in length.

B&E Body shafts are of a larger diameter than A body shafts.
They wouldn't fit in an A body crossmember.
So your theory won't work.
 
-
Back
Top