How Flush Should Sway Bar Link Ends Be?

[Muzez 38]

Hey Guys, 

Replacing old rubber Sway Bar Link Ends this week with new Poly ones. QQ: How flush is the bushing supposed to sit on the sway bar?

The old rubber ones contoured to the curve of the metal of the bar, but mostly because they were 43 years old and absolutely shot. As I am tightening the poly ones, they don't have as much flexibility and so they don't align as nicely. I assume this is okay, but wanted to check first before hitting the road. (Disclaimer: Sway bar ends are not tightened in the photos. Took the photo when I first put them in place, but forgot to take a tighted photo before leaving the shop.)

[Captain Obvious 2,359]

I believe the poly should operate the same way the originals do. Meaning...

There should be a metal sleeve that runs through the center of the bushings. You're supposed to tighten the nut down until there is metal-to-metal contact between the washers and that sleeve. The compliance of the bushings is supposed to compress until that point. In theory, you should be able to feel the tightening torque shoot up once all the play has been taken up.

[Pilgrim 141]

^^Agreed. Been doing this on my 280ZX. There is a torque spec for those in the service manual, too.  Might be around 40 lbs/ft but check it, don't trust my memory.

[Captain Obvious 2,359]

pbbbbbt. Torque spec.  

Seriously though. I'm sure there's a spec, but 40 ft-lb sounds a little high for that small of a bolt. Another vote to check the manual.

[EuroDat 540]

The kit I used didn't have spaces in the rubber. It did have an extra waher and just one tube spacer between the swaybar and lower control arm.

See Pos nr.9 & 14 in the Hyperflex dreak down photo.

280Z Hyper-Flex Kit.pdf

[Muzez 38]

2 hours ago, Captain Obvious said:

Seriously though. I'm sure there's a spec, but 40 ft-lb sounds a little high for that small of a bolt. Another vote to check the manual.

@Captain Obvious & @Pilgrim Didn't find it in the Haynes manual or in the Datsun FSM. Is there a different term people use for it other than Stabilizer or Sway Bar Link End?  

@EuroDat that's the same setup I have. Also, and unrelated: I hope its not too forward, but you got a nice undercarriage. 😉 

 

 

[Pilgrim 141]

In my 1983 ZXT manual it's on pages FA-4 or FA-8. The diagram on FA-4 is best.  Glad you asked, it's a very low torque spec, 12-16 Lbs/Ft. 

It would help if you'd mention the year of your Z, just in case it's quite different.

Edited September 28, 2020 by Pilgrim

[EuroDat 540]

Oh crap. Wrong photos. Now Ill try that again.

You are wrong on with your comments about not fitting well. They do pull in with a little persuasion. I used a block of wood and a trolley jack to compress them enough and start the nut. See second photo.

Another point. My kit was 4 rubbers and washers, simple bolt, nyloc nut and a spacer tube. If you tightened down hard , you could crush the rubbers completly. I tighted the nut until the rubbers started to bulge slightly. Checked them aftrr a couple of monthes and retightened a little where needed.

I hope that makes some sense.

 

[Pilgrim 141]

Nice photos!!

Also helpful comment on using the wood block and separate jack.  Been ruminating on how I was going to press that bar up into position.

[EuroDat 540]

Back when I did that (in 2012) most people were buying longer bolts that would stick out about an inch above the nut. The original bolt is long enough to get one full thread past the nyloc ring. 

Edited September 28, 2020 by EuroDat

[Muzez 38]

33 minutes ago, Pilgrim said:

It would help if you'd mention the year of your Z, just in case it's quite different.

Sorry, was posting while in a meeting, am a terrible multitasker. 1977 280z. 

[Muzez 38]

35 minutes ago, EuroDat said:

Oh crap. Wrong photos. Now Ill try that again.

You are wrong on with your comments about not fitting well. They do pull in with a little persuasion. I used a block of wood and a trolley jack to compress them enough and start the nut. See second photo.

Another point. My kit was 4 rubbers and washers, simple bolt, nyloc nut and a spacer tube. If you tightened down hard , you could crush the rubbers completely. I tighten the nut until the rubbers started to bulge slightly. Checked them after a couple of months and retightened a little where needed.

I hope that makes some sense.

Makes perfect sense. Will give this a try with the jack tonight and will update you on the progress! 

[zKars 1,220]

8 hours ago, Captain Obvious said:

I believe the poly should operate the same way the originals do. Meaning...

There should be a metal sleeve that runs through the center of the bushings. You're supposed to tighten the nut down until there is metal-to-metal contact between the washers and that sleeve. The compliance of the bushings is supposed to compress until that point. In theory, you should be able to feel the tightening torque shoot up once all the play has been taken up.

Interesting. I’ve never seen a metal sleeve that fits inside the ID of the bushings. Just the ones that set the spacing between the two bushing stacks. Stock end links that I’ve cut off, or any of the after market ones I’ve bought since have never had one. What you get is in the picture below.

I totally agree there SHOULD be a sleeve to set the bushing compression, that would eliminate the guesswork of how much to tighten them, but that’s not the usual reality of what you have to work with. 

Tighten enough so bushings are compressed so that no metal to metal contact is possible and the bushings can still compress enough in use during travel. If your sway bar hole or hole in the control arm is all ovalized out, they weren’t tight enough. 

 

Edited September 28, 2020 by zKars

[Captain Obvious 2,359]

OK, so there are a whole bunch of votes that say the spacer I described isn't there. And admittedly, I did not go out to take a look at my car. It's quite conceivable that I was mistaken and simply describing how I THINK it should be designed.

In any event, you're in good hands. Ignore me. 

[Pilgrim 141]

I checked the parts for my 83 ZXT. The tension rod bushings have a tubular metal inner sleeve, but the sway bar end bushings do not.

Edited September 29, 2020 by Pilgrim

[dutchzcarguy 232]

6 hours ago, Pilgrim said:

The tension rod bushings have a tubular metal inner sleeve, but the sway bar end bushings do not.

Dito, for my 240z and 280zx..

[zKars 1,220]

Captain O, you have earned the right to now produce the sway bar end link Torque limiting position sleeve product (SBELTPS) and sell it to the masses as it clearly is both an excellent idea and a glaring omission in the original design. These things are used in millions of cars throughout the world, the market is massive.

It will require custom bushings as well as the ID has to be slightly bigger to allow room for the sleeves. Millions of happy users will result and cars will handle better and make less noise from loose bushings, and preserve the holes in their control arms. 

At the very least, sell the idea to Energy Suspension and get rich doing nothing. You’re welcome.

[Captain Obvious 2,359]

Haha!!! I'll get right on that! 

[crayZlair 22]

18 hours ago, EuroDat said:

 I tightened the nut until the rubbers started to bulge slightly.

 

 

 

I bulge the rubber just slightly more than the diameter of the steel washer. Always seems to work out well.

[Muzez 38]

More bulge than this right? Or just past the washer is enough. 

[crayZlair 22]

Lookin' good!

[EuroDat 540]

It looks ok. That is about what I did on mine.

Did you use another longer bolt or shorten the spacer tube? My bolts were just long enough and I needed a block of wood to compress the rubbers to start the thread.

[gnosez 202]

The best way but not one available to everyone is to put the car on scales, the ones used to corner balance the car and tighten until you see a difference in weight shifting from one side to the other. One starts corner balancing with the sway bars disconnected,