Rubber parts. Do they go bad by age or mileage?

[thelinux]

Today, I tried my friend's VW. His has 30K miles on it. only 2 years old.
The car still rides like new. I am talking about the ride quality. Everything feels tight and solid like new car.

My Z has less mileage than his. (Only little over 20K miles) But mine is 5 years old. But the ride of my Z feels a lot loose than his.

Not sure how I would describe this. I am not talking about the performance but about the quality of the ride.

His feels like every bolts with suspension are up to spec. Mine makes me feel like some bolts are loose. Can you guys see what I am talking? Overall I feel like my suspension worn out more than his even though mine has less mileage.

You guys probably know that with new cars, you feel every parts of the suspension are holding tight each other, but with old cars, you feel that all suspension parts are somewhat loose.

Anyway, I am not sure why mine feels older than his even though mine has less mileage.

Can the reason behind this be the fact that rubber bushings on mine are older than his VW? Or is there any other reason?

I am thinking to replace all the rubber bushings on the suspension of my car.
How difficult to replace rubber bushings? How do I do it? Any tips???

[StickMon]

1) They go bad by both age and mileage. I'm not far from you, and the SoCal heat + ozone + dry makes rubber parts age more quickly than they would in other parts of the country.
2) Replacing bushings is a many faceted subject. Some are easy, like sway bars, some are harder, like control arms.

Have a peep and a poke under the car and see if there are any cracks in any of the bushings.
My car's 2 years older than yours, and very close to 100k miles.
I inspect the bushings regularly, and I'm still OK, so I don't think you should lose much sleep over it.

[Finnegan]

40K miles, 12/06 build. All bushings replaced (poly for most). Car feels like new. Wife's Z has a little over 30K. Original bushings. Guess what's next on the to-do list after she drove mine?

[StickMon]

Just got BavAuto's newsletter the other day, with this link in it.

They want $150 for the taker-offer and putter-onner set.
Not too bad a price, but I hate to pay it for a tool I'll probably use once in my life.
Thinking about copying it with bits from Lowes.

[GeorgeT]

I'm not sure that comparing a ride in a VW to the ride in a Z4 is a valid comparison.

[thelinux]

Originally Posted by StickMon

1) They go bad by both age and mileage. I'm not far from you, and the SoCal heat + ozone + dry makes rubber parts age more quickly than they would in other parts of the country.
2) Replacing bushings is a many faceted subject. Some are easy, like sway bars, some are harder, like control arms.

Have a peep and a poke under the car and see if there are any cracks in any of the bushings.
My car's 2 years older than yours, and very close to 100k miles.
I inspect the bushings regularly, and I'm still OK, so I don't think you should lose much sleep over it.

By any chance do you know which bushings needs to be replaced? I mean which one contributes to the ride quality most?

[thelinux]

Originally Posted by Finnegan

40K miles, 12/06 build. All bushings replaced (poly for most). Car feels like new. Wife's Z has a little over 30K. Original bushings. Guess what's next on the to-do list after she drove mine?

Which bushings did you replace? I looked through realoem parts diagram and I found a lot of rubber bushings used under Z.
About poly bushings? Aren't they make the ride more hard or even harsh? What's the difference between rubber and poly?
Which brand did you use?

[thelinux]

Originally Posted by GeorgeT

I'm not sure that comparing a ride in a VW to the ride in a Z4 is a valid comparison.

I know what you mean, but like I said (hard to describe) this is not about how hard the ride is but about well...... how new the ride is maybe????????

I feel the samething whatever newer car I drive. The point is, my car has only 20K miles but still feels like over 50K miles on it when I drive.

[Finnegan]

Originally Posted by thelinux

Which bushings did you replace? I looked through realoem parts diagram and I found a lot of rubber bushings used under Z.
About poly bushings? Aren't they make the ride more hard or even harsh? What's the difference between rubber and poly?
Which brand did you use?

Pretty much used poly where ever possible. Replaced pretty much everything, RTABs, FCABs, ARB bushings, subframe bushings. No, it's not harsh, it's just solid, planted, and precise. In most applications, poly lasts longer, and it affected to a lesser degree by heat. YMMD.

Powerfilex E36/E46 RTABs, Superflex FCABs. I did the subframe as well (long story I won't go into, you may not want to do it unless you're taking off the diff).

It's a long list of part numbers, I'll be honest, I don't want to type them all in. Go to ECS Tuning and put make/model, then look at all suspension parts. ECS also makes refresh kits I believe, call them, they can probably help you put a custom kit together.

[Walkurie]

Bought a low mileage (29k) Jag XK8 for my wife last year. One of the first things we did was replace all the rubber cooling system parts. As it turned out, just about everything was brittle and ready to go. Bushings are next.

[GuidoK]

It also depends on the roads you drive, the way the suspension is set up and the quality of the bushings.

Stiff suspension (springs/dampers) give bigger impulse loads on certain bushings.

Completely polybush your car will transform it. The rear end is just as important as the front end. Just drop the rear axle and the rest is pretty easy. (so you'll need a car lift, transmission jack, a universal bushing puller set and maybe some large sockets)

[Finnegan]

Originally Posted by GuidoK

It also depends on the roads you drive, the way the suspension is set up and the quality of the bushings.

Stiff suspension (springs/dampers) give bigger impulse loads on certain bushings.

Completely polybush your car will transform it. The rear end is just as important as the front end. Just drop the rear axle and the rest is pretty easy. (so you'll need a car lift, transmission jack, a universal bushing puller set and maybe some large sockets)

Yep. No exact or perfect answer to "age" or "how many miles". Lots of variables at play. That said, I'd say that in 99% of cases, by 5 years and/or 50K miles, it's a safe bet that it's time for a refresh.

[jdoublehcubed]

Poly is definitely the way to go, very very very little increase in harshness, and probably twice the lifetime of rubber.

You don't need a special puller like that bavauto one. Just get an oversize ball joint press and a set of bearing adapters, and you should be good to go. The RTAB and subframe are beyond most DIYers, you probably want to pay someone to do those. If you don't have a lift, you're looking at 10s of hours of work.

[elerner61]

I'm very interested in doing this. I'm at 6.5 years and 41K miles of Northeast climate with so-so roads. At slow speed over bumps (such as the cement curb on my driveway) it sounds like front end components are bouncing around and not firmly secured.

1. I am cautious about using Poly, due to my rough roads. Jdoublehcubed, how are your roads around Philly and the Poly didn't make the ride noticeably rougher?

2. Other than the rear RTAB and diff bushings which seem to require droping the rear (not interested in doing, unless I'm making it bigger than it is), how much of the fronts is a DIY? How long will doing all the front bushings take?

Thanks,

Evan