83 280ZX radius arm bushing
 

I got some new tires at Pepboys. I had them also take a look at my suspension and bushings and etc. I had already noticed a couple of bushings look pretty cracked up. I wasn't sure of which ones they are. Anyhow, Pepboys came back and told me my radius arm bushings need to be replaced. I browsed zcarparts.com and found some control arm bushings but I can't seem to find anything that uses the word radius. Can someone point me in the right direction?

Also, I would love to replace some other components if there would be at all any kind of improvement to the car overall so if there are some kits you think I should take a look at then let me know.

As for the control arm, I found upper and lower control arm bushings but what is this radius arm bushing and why isn't it listed by zcarparts.com?

Regards,
jmw_man

Okay, I think I figured out what it is. It's the tension rod to chassis bushing that looks pretty bad. When he said the radius arm, I assume he was referring to that. I found the part on zcarparts.com but if I'm going to replace those I'm wondering if I should go ahead and replace others. Even though the other bushings don't look bad, is it possible that they could still be bad and/or would I gain any improvement from replacing other bushings that might not look bad? I figure I might as well replace everything if I'm going to be taking stuff apart but I also don't want to throw away money if it's not needed.

Thanks,
jmw_man

Might as well replace everything while you're in there since they're usually all in the same condition. Poly bushings make a big difference.

Okay, next thing I wonder is, OEM is important right? It's my understanding that the bushings are designed to wear and tear before metal components break like the control arm, sway bar, tension rod, etc. I even read somewhere where people had problems with tension rods snapping due to non-OEM tension rod bushings. Is anybody familiar with this?

I replaced my oem bushings with poly ones and it was amazing and no problems with it, nothing was bent or broke.

Can someone confirm to me how many tension rod bushings and how many stabilizer bar bushings I should have? I'm referring to just the front suspension right now. The FSM isn't 100% clear and I originally thought I needed 2 stabilizer bar bushings on each end of the stabilizer bar but when I look under the car it looks like I see 4 stabilizer bar bushings on each end. Can you guys confirm this? I really want to avoid pulling stuff apart only to find out I don't have all the needed parts.

I ordered some bushings already. Again, I'm just working on the front suspension right now. I received 4 tension rod bushings, 2 stabilizer bar bushings, and 4 stabilizer bar end link bushings. I have a feeling I should have gotten 4 more stabilizer bar end link bushings. Let me know for sure.

Thanks,
jmw_man

EDIT: Added rear bushings for clarification.

Front:
2 bushings per tension rod (4 per car)
4 sway bar end link bushings per side (8 per car)
2 sway bar frame mount bushings

Rear:
4 sway bar end link bushings per side (8 per car)
2 sway bar frame mount bushings



Click:

http://nissan4u.com/parts/280zx/us_s...llustration_3/

http://static.nissan4u.com/epc_img/57333484001988.png

Click:

https://www.zdriver.com/forums/280zx...ol-arms-35855/

(Link is upside down for photo simplicity's sake)

https://www.zdriver.com/forums/attac...ms-sb-link-jpg

Don't use urethane bushings on your TC rods. I know some guys get away with using them on one side - just don't remember which - probably the rear one. Lots of horror stories about TC rods breaking from urethane bushings - not worth the risk to loose your steering while you're driving...

Nismo, is that a typo on the sway bar end links? It says 4 per side and 8 per car. Don't you mean 4 per side and 16 per car? On second thought...

Maybe that "per car" stuff is confusing me. The part numbers for the sway bar end links on the front suspension are completely different from the part numbers for the sway bar end links on the rear suspension so I wonder if maybe when you say per car you are really referring to just the front suspension?
*edit* On the tension rods, sorry Nismo, I think I'm going crazy, lol.

Yea, I looked at them and read around. I pretty much decided I prefer to go OEM. I figured they serve a purpose.

Yes... there are 8 for the rear too, but you said this:

Since you are / were only referring to the front suspension, I said there are 8 end link bushings for the entire car's front suspension.

If you want rears, buy them... I was answering the question you asked. :D

Cool deal, thanks.

That really sucks though because I only bought 4... now I have to wait even longer for the other 4 to get here...

Don't use urethane on the tension rods, my tension rods have snapped twice on me because of them, first time i was just cruising down the highway going 60 and all of a sudden it felt like a rock came up and banged my floor board, but it was the rod snapping, second time i was going over the metal plates they put on the ground during road construction and it snapped again.
It broke in the same place too, right where the bushing rides when the rod takes a step down and gets narrower.

Did you have two urethane bushings on each tension rod or did you do half urethane half rubber? I've read in many places not to do full urethane but in several places people mention doing half and half.

I was using full urethane, if you are going to do half and half (which I don't think has any benefits) I would put the rubber in the front and the urethane in the back. but if you want to be worry free and safer, just use all rubber, I really felt no difference going from urethane to rubber.

Agreed. The biggest difference probably is going from worn out destroyed bushing to new rubber ones rather than from new rubber to urethane. Most guys take the old rotten ones out and put urethane in and are amazed how responsive the car becomes - they would likely do the same thing with new rubber bushings in the TC rods. If you're going to AutoX the car then you could go with the TTT TC rods - they are beefy and they use a hemi joint so there isn't any play.

I'm an engineer and have some knowledge of material science. Here's a bit of knowledge. All materials have a yield strength which is basically the definition of the point at which a material will deform (yield). Materials also have a tensile strength which is basically the definition of the point at which a material will fail.

If you stress a material to its yield strength and release, the material will return to its original shape, if you stress a material to its tensile strength, it will break.

The rubber bushings obviously have a lower yield strength than the polyurethane bushings.

Now, when we are driving down the road, there are all sorts of forces interacting with different components throughout the car causing fatigue. There's nothing in the world we can do to remove those forces and the resultant fatigue except rebuild the roadways without potholes, cracks, bumps, etc (which is fine on the racetrack). The only thing we can do is dissipate that energy. Well, all cars have shocks on them, however, shocks only work axially (the two ends of each strut/shock never move from that axis). As far as cyclic loads are concerned, shocks can only dissipate the portion of those loads that are parallel to the shocks themselves. The other portion of those loads must be dissipated by other means. That's why we use rubber bushings. We use them because we want them to take the majority of those loads (not parallel to the shocks/struts) away from all other components on the vehicle. In other words, we want them to wear out before anything else does.

mrprofile is probably right about half and half not having any benefits. It means the poly side won't yield, and the rubber side will receive twice as much cyclic loading which means it will wear out twice as fast.

BUT, some people use poly and to protect their tension rods they do some welds to increase strength like what Nismo did, or they buy some other aftermarket tension rods that are stronger. However, those loads are still there and are still transmitted to something else, to what, we may never know until someone has used poly and stronger tension rods and has been driving their car for another 30 years after such work and can give us his experience. It may mean the tensile strength is NEVER exceeded on any component and you just have to deal with a bumpy ride for the life of the car, or it could mean some loosening of nuts, bolts, screws, etc over time. Personally, I'd prefer to just stick with the original design and assume the guys at Nissan knew what they were doing. In my case, it is a street car after all.

jmw_man

That is a good opinion, but not everyone wants their car to perform / feel like a stock 30 year old car (suspension technology has come a long way in the past 34 years). :D

Nissan engineered the car to be a mid-priced (affordable) performance car. There were / are always upgrades that can be done to improve performance.

30 year old car, yes, but 1 year old rubber bushings :D

Actually, even rubber design by itself could have come a long way so you could technically say that new rubber bushings of today are better than new rubber bushings in 1983.

Same goes for the struts or any other component in an old car, buying new replacement parts that are considered OEM aren't necessarily manufactured with the same materials and/or by the same methods.

It's pretty simple - not AutoXing the car - rubber bushings. AutoX - get the TTT TC rods. That way you're not worried about your testicle strength and strain er I mean tensile... :0

I thought yield was the point at which the bolt doesn't bend back, because some cars have torque-to-yield bolts that are tightened to a certain point and the bolt actually gets longer, permanently to give it more holding strength.

You're right, my wording was incorrect. Yield strength is the transition point. So above the yield it won't return to original shape, below the yield it will return to original shape. I guess you could treat at the yield as above the yield since the transition has already began.