'99 V70 -- IPD Heavy Duty Sway Bar Link Catastrophic Failure

[northernlights]

They are thick (hence the HD designation) and so they reduce flex...

...who cares about bar thickness if the joint can't handle it. Maybe the rod thickness helps puts too much stress on ball joint

That's an interesting thought.

How much thicker are they? A sway bar stiffness increases in proportion to the change in diameter to the fourth power, as in [D(new)/D(original)]^4. Even a small change in diameter might allow significantly different forces to be applied to the joints instead of being used to flex the suspension.

It's an interesting problem to consider, because the sway bar links are pretty spindly looking compared to the bar on all of the FWD vehicles I can think of.

[northernlights]

If I had looked before I posted..... 12mm vs 10mm according to the web page, so about twice as stiff.

[Ben850]

If I had looked before I posted..... 12mm vs 10mm according to the web page, so about twice as stiff.

That means they are less likely to bend. They usually don't anyway.

It has nothing to do with the longevity of the ball and socket integrity.

[E Showell]

Steve. --feel free to share. In the interest of full disclosure, I bought a replacement pair since I want to keep matched components on each side of the car, but only installed one since the passenger side IPD heavy duty link has not failed. If you pm me your email address, I will send photos of the failed part which you can post or not as suits you.

[E Showell]

Redneck -- I have had a similar, positive experience with FCP and have bought many hundreds if not thousands of dollars worth of parts for two cars from them. Their customer service is unparalleled in my experience across all retail platforms. I'll use my local dealer for parts I need same day, but generally I'll order from FCP since they are relatively close and even economy shipping is prompt and their pricing is outstanding in my experience. Whenever I've gotten a bad part from them, they have bent over backwards to make things right.

Case in point. I recently had to replace an aftermarket axle I had bought from FCP (Empire brand -- stay away). It failed in about 13,000 miles. I didn't have any of my original paperwork, but they acknowledged 13,000 miles was premature failure for an axle. Since I had already purchased and installed a replacement rebuilt OEM from Colorado Driveshafts (if memory serves Raxles was out of stock), FCP immediately credited my account for the cost of the failed axle and shipping. Can't ask for more than that.

[northernlights]

If I had looked before I posted..... 12mm vs 10mm according to the web page, so about twice as stiff.

That means they are less likely to bend. They usually don't anyway.

It has nothing to do with the longevity of the ball and socket integrity.

I bet they flex a bunch. They don't stay that way, but under load is a different story. The bar is probably about one inch, and look how much that thing has to move with the body. The links have to transmit all of the load from the bar to the front wheel through the strut.

If the stock links flex more than the HD's, then the load on the joints can be different, maybe outside of the design range, so that it tried to lever them out.

Just imagine prying on something with a wrecking bar vs an equally long screwdriver. The wrecking bar won't flex nearly as much.

[Ben850]

I was speaking to the point of failure or damage.

[dosbricks]

The sway bar transmits load via a twisting motion so it's correct to conclude a small change in diameter there would significantly change the amount of force transmitted.

The sway bar end links transmit their load more or less along the vertical axis of the bar so the geometry is not such as to create that much flexing--mostly a push pull force--since their range of lateral motion is not all that great. IMHO, the failure of the IPD endlink ball and sockets is probably due to poor quality construction.

Just for the record, I went out and measured with a caliper the diameter of the bar on Meyle HD and Volvo OE endlinks. The Meyle is 10mm and the Volvo is 8.5mm.

[Beck]

I blew threw 8 IPD end links in one year and then I switched back to OEM and have been fine since.

[ThommyKent]

I like IPD, unfortunately they are starting to include cheaply made parts in their inventories. You need to carefully look at what they sell now to avoid them. A new owner has taken over and it appears money is more the object than quality. Rather sad actually.