Goodbye Poly

[jfa.series1]

Where did you source a rubber steering coupler?

C

I didn't. I'm going to re-use my original which is still in excellent condition.

[gnosez]

I would have been interested in hearing your thoughts if you just swapped out the steering coupler and then drove the car before taking out the rest of the poly.

[jfa.series1]

I would have been interested in hearing your thoughts if you just swapped out the steering coupler and then drove the car before taking out the rest of the poly.

Now you tell me! Just kidding.

As one of our members said at the tech session, swapping out the steering rack bushings is not going to make up for the solid eccentric bushings in the control arms - some harshness is still going to get directly transmitted to the subframe. With just a few miles on the car since the changes, I can tell that the T/C rod bushing swap has improved front end ride quality. With the rack and coupler changes I'm looking to reduce snap that feeds up to the steering wheel.

[Patcon]

I was hoping you had a source. All I have seen is poly replacements. I haven't seen any rubber steering couplers for sale. NIX240z can you mold these in the correct material?

Charles

[madkaw]

I wonder about the quality of todays rubber parts(bushings) compared to yesteryear. I mean technology seems to have advanced most products in the last 30-40 years-why not rubber. My point being that a lot of folks go straight to poly thinking that the rubber will degrade rapidly with hard driving.

'That if you want the sports car feel with quick handling you need to go poly'-is that really true?

Do most of us drive our cars hard enough to warrant the need for poly or we are going to tear up rubber bushings? It would be cool to drive two identical cars that were bushing differently-one urethane and one rubber.

Maybe the answer is running half and half to get a sporty ride and refinement too!

I guess its all in how you use your Z or what your goal is for the car. I'd like to have it all, like todays cars, sport ride and comfort(refinement). Being mostly all urethane on my car I don't have real issue with my ride quality. Reducing road noise would be nice in order to hear my engine and exhaust better would be sweet-but as it is, it's not that bad.

Finding out the TC kit is so reasonable and available, I might consider changing them out.

[John Coffey]

I've never seen a rubber bushing "torn up" from use. They crack, fail, come apart from age, ozone, and oil. What polyurethane bushings give you is more accurate suspension locating under load - the suspension geometry changes less under load as a result of bushing deflection. This is only a concern if you're re driving at 9 or 10/10ths which is nearly impossible on the street if you value your life. OEM style rubber bushings work fine in all cases except for autocross and track use.

What a lot of people make the mistake of doing is comparing worn out rubber bushings with new poly bushings and then claiming that poly is so much better. The same false comparisons occur for brakes, engine, transmissions, differentials, seats, etc.

[Lazeum]

Some bushings are more critical than others regarding ride and confort.

For steering feel, T/C rod busings, steering coupler and rack bushings are the most important.

Other bushings are mainly for confort and car behavior at the limit.

If I were to do a mix of poly and rubber, I would do front LCA & rear LCA in rubber and keep T/C rod & steering bushings in poly.

If I would be smart, I would either get T/C rod bushings in rubber to be safe since we all know potential problem with poly (yet to be demonstrated to me) or go with ball joint instead of bushings at T/C rods (such as T3 front LCA)

[zKars]

When you front wheel drops into a washout hole, or over a sharp bump, there is considerable force backwards at this instant as well, directly into the T/C rod. If the bushing on the front of the T/C rod pocket is non-compliant, ie the Delrin ball thing or a solid heim joint on who's ever adjustable T/C rod, then that shock goes directly to the frame and to you as a nasty jolt rather than being partly damped and absorbed by the rubber bushing. I'm pretty sure John has mentioned this in the past.

This is one reason I kind of like the forward T/C rods on the ZX and 510, you can put a solid mount on the back (wheel) side, and a soft rubber on the front, which gives you better location under decel (compression) helping steering inputs, but bump compliance when you drop a wheel in a hole and get that rod in tension. Everybody go out and flip your T/C rods to the front! Just takes a little welding and rack link bending for clearance, no big deal.

I kept all the several stock rubber steering insulators from all the guys I've done poly replacement jobs for, just waiting for this moment of revelation. If anyone really wants a stock one back, let me know. $5 + a stamp. Maybe I should make it $100 each to make us pay for our foolishness! . Guess I'de better keep one for myself.

[jfa.series1]

The OE steering rod coupler went back in today and that wraps up this set of changes. Tomorrow is Cars & Coffee for the Dallas area and some of our Z Club of Texas group will be making a back roads lunch run up to Dennison for some BBQ. This will give me a good opportunity to get some butt feel for the recent bushing swaps. A trip report will be forthcoming.

[zKars]

I'm about the "join the gang" here and put some rubber back in my front end. No, the Z"s front end silly! Clearly I'm getting soft in my old age and want my Z the same way. Good bye AZ Z Car adjustable control arms with your solid mounts.....

Unfortunately the strut rod bushing kit AC Delco 45G25036 appears to be no longer available. Rockauto, partsgeek and others I've googled either don't have it, or it crosses to a kit that only contains the 4 rubber bushings. Moog K9215 is still out in good numbers, but also only contains the bushings,

Have a look at your favorite sources and see if you can still find some. Its nice to get the new washers, central spacer tube and a new nut.