control arm bushings...

[Russell]

This is why I want to remove the derilin inserts. They are a great idea and seem to work very well to eliminate shimmy and stiffen up the front end. They are not for everyone. However, I suspect additional stress is being placed on other components.

As this is my commute car/daily driver, reliability AND comfort are important.

[Kalevera]

bmw engineers went to a lot of trouble to design the stock bushings and a fine line was walked to give you the best tradeoff in ride comfort versus handling versus durability. Anytime you stiffen up an area on the stock suspension there's going to be a tradeoff in harshness and instead of wearing out the bushings it will instead transfer the load to other components and wear them out quicker. I see this a lot with people who think they need urethane bushings, but if your willing to put up with the tradeoffs then go for it. Last week i replaced the radius arm mounts on a bronco who had put extremely stiff urethane bushings on them 6 months ago and now he actually broke out the radius arm mounts where they are riveted to the frame.... I see this a lot on trucks here with the urethane suspension components kits for handling.

I utterly agree with Bill.

A couple months back, Brett Anderson sent a link to UUC of a video hosted on our web site that showed an utterly destroyed set of urethane upper control arm bushings that had recently been installed. We changed web servers recently, and I can't remember the IP to the old one so I can post the link to that video.

Regardless, here's the UUC discussion about it...

http://www.mail-archive.com/bmwuucdi.../msg06463.html

and

http://www.mail-archive.com/bmwuucdi.../msg06465.html

Particularly:

"> An issue with "U"rethane bushings that everyone fails to take into account
> is the degradation in spring rate.
>
> Replace your control arm bushings with urethane and leave stock
> springs and
> shocks in the car and you've just done the equivalent of putting softer
> springs in your car. Yeah, there's an upgrade for ya.
>
> Urethane inserts in a stock bushing are a different thing entirely and
> shouldn't be compared with the general inability of urethane to do the job
> for which it's sold.
>
> If you have a street car, use rubber. If you have a race car, use metal.
>
> Brett Anderson
> KMS"

best, whit

[BigKriss]

I utterly agree with Bill.

A couple months back, Brett Anderson sent a link to UUC of a video hosted on our web site that showed an utterly destroyed set of urethane upper control arm bushings that had recently been installed.

the video was around a while back, what brand was it?

[Gene in NC]

OK, I buy rubber bush but what is source of m5 thrust and will Grandma accept them on her '89 525. UUC comment re 750 bush 50% greater life didn't make it for us. Orig 60k, 750 83k. Rember Grandma is the driver.

[Kalevera]

Gene -- The 750 bushing must've been improperly installed/not torqued with the suspension under load.

M5 bushings are available from Patrick, the dealer....tons of places...WorldPAC (if you have a wholesale/reseller account )

best, whit

[fkong777]

just swapped out my urethane thrust bushing with a new pair of Hamburg Technic thrust arms and 750il bushing.

Ride quality is day and night difference. Urethane was so harsh that I didnt like driving the car anymore. Swapped out to the new arm/bushing. I'm loving the car again.. bought back all the luxury that I lost with Urethane bushing.

true the steering response is not as good but it is embrassing to have a harsh riding E34 when you have passenger expecting a luxury car ride.

[632 Regal]

These are NOT luxury cars, they are a "Drivers" car.

[Russell]

I do not think that BMW intended thier mid range sedan to ride like an old pickup truck. IMO, thats the way they ride with solid or near solid thrust arm bushings.

These are NOT luxury cars, they are a "Drivers" car.

[TheDuke]

750il bushings Will these work with 525i?

[infinity5]

Is there an online source of information about urethane stuff in general, particularly hardness, measued in.. what is it? durosomething? Shouldn't the particular stiffness of the particular urethane be more important than simply that vs Rubber? Or can they only get so soft, at which point they're still too hard to use?