Advice please - new NAPA balljoint lacks cotter pin

[stuckagain]

I thought I would finish the front end work today on a 1990 Subaru Loyale 4WD. I bought new balljoints from NAPA last week. They sell two varieties: cheap and expensive. I opted for the expensive ones. When I pulled one out of the box I noticed that there is a self locking cap nut, but no hole for a cotter pin. Has anybody else used these? Should I take them back? They appear to be well made and identical in size to the ones I pulled off the car.

 

As always - thanks in advance.

 

Stuckagain

[Humble Nuto 53]

nylock nuts are fine...

[stuckagain]

Are you certain Nylock (or other brands) of self locking nuts are O.K? Can you cite a reference of some sort? Self locking nuts on a 1990 Subaru would be considered a modification. I found at least one example of "self -locking" nuts that failed when used in the front suspension. The sevice bulletin advised drilling out the stud and using a cotter pin. A copy of the bulletin is here:

 

www.dmcnews.com/bulletins/SC-01-11.81.pdf

[beauregaardhooligan]

The link didn't work for me.

I tend to follow the parts manufacturer's recommendations.

They probably figgered out that the nut is sufficient.

If it isn't, they would be liable.

What do the installation instructions say?

[TurboSPFI]

If they didnt work why would they sell them?

 

BTW: If a balljoint snaps, that cotter pin wont help.

[Petersubaru]

I have used the lok-nut style on Vw's with no problem..use them together with some red or blue lock-tite....once they tighten-up and age you will need 250 lbs air tool to take them off.....

I thought I would finish the front end work today on a 1990 Subaru Loyale 4WD. I bought new balljoints from NAPA last week. They sell two varieties: cheap and expensive. I opted for the expensive ones. When I pulled one out of the box I noticed that there is a self locking cap nut, but no hole for a cotter pin. Has anybody else used these? Should I take them back? They appear to be well made and identical in size to the ones I pulled off the car.

 

As always - thanks in advance.

 

Stuckagain

[stuckagain]

TurboSPFI wrote: "If they didnt work why would they sell them?"

 

The fact that something is sold is no guarantee that it is safe or works. I used to be a mechanic for VW-Porsche-Audi. We used to receive reams of "Service Bulletins" advising us to change things that had already been sold (some for many years). I assume that this is true for other makes of vehicles and for parts.

 

Here's a corrected link to the "Service Bulletin" I found on the web: http://www.dmcnews.com/bulletins/SC-01-11.81.pdf

 

I called a friend who has been an automotive engineer for the last 20 years; his field of expertise is military trucks. Here's what he had to say about self locking nuts:

 

 

A high-quality self-locking metal/metal nut is generally a good torque retentive fastener as long as it is installed correctly and used only once. A castle nut with a cotter pin has some field repair advantages in that you can reuse it. You can reuse the torque retentive nut as well, but it will generally not have the same locking capability on subsequent uses unless it has a torque retentive thread form such as "SPIRALOC" Torque retentive threadforms are more than just squished nuts it is the actual thread form that prevents torque loss. They must however be properly installed, and if they lose preload in service they may lose effectiveness, so the best combination is a locking thread form like SPIRALOC combined with a crushed nut. One bad thing with respect to metal/metal self-locking nuts is the bad habit of nuts, particularly large sizes and stainless steel of welding to the bolt during installation particularly when using an impact wrench. It can also be more of a problem if a self-locking nut is installed on a soft-bolt. It will likely chew up the thread as the nut is harder than the bolt. SPIRLOC nuts are used to fasten the solid rockets to the space shuttle - this part of the space shuttle has not failed yet.

 

Nyloc elastic nuts are generally not used in my business for critical fastening because they start to melt around 150 deg F. There are high-temp elastomeric nuts that have higher temp limits. Overall I think it is the trend, and good practice to install a metal/metal toque retentive nut in this application. It will be harder to remove, but maybe that's a good thing, and will make future replacement more time consuming. But that is only important to the customer, umm, oh that's you, huh....

[MorganM]

The nuts they give you are fine. Can I site some literature to prove this? Not really but that doesn't mean they are worthless. I think you are making a bigger deal out of this than is necessary. If you don't belive what we are telling you and don't want to run those nuts; go buy a really expensive Genuine Subaru Part.

[stuckagain]

The nuts they give you are fine. Can I site some literature to prove this? Not really but that doesn't mean they are worthless. I think you are making a bigger deal out of this than is necessary. If you don't belive what we are telling you and don't want to run those nuts; go buy a really expensive Genuine Subaru Part.

 

OK - I was just skeptical about the nuts. I installed them yesterday. I match marked them 'cause I'm paranoid I guess. They're not spec (like NAPA said they were) and it cost me a day because it caught me off guard. I just want to make sure it's OK (there are other posts on other lists asking the same thing - so I'm not alone). The mfg makes them this way not for my benifit, but to reduce their costs. Not all parts are the same - ask any 70-80's era VW mechanic who had to install mufflers made in Mexico. I just want to be sure I'm doing it the best way possible.

[MorganM]

I just want to be sure I'm doing it the best way possible.

 

Then you would have bought Subaru Genuine Parts and not NAPA

 

It's America; if they fail you sue!