Urethane Thrust/ Control arm bushings? anyone have any experience....

[JeremyT]

Well, Merry Christmas & Happy Holidays to everyone.
I saw these things on eBay and brought back a question I've had in my head for a while.

http://cgi.ebay.com/ebaymotors/ws/eB...category=33583

Has anyone had any experience with urethane bushings for the control arms or thrust arms? I made the mistake of getting meyle parts w/ the 750 bushings for my 750 and it's killed them inside on 30k miles. Any thoughts on these bushings? I'm still redoing my 535 and wanted to put the right parts on it the first time. Thanks eveyone.

[DueyT]

Jeremy, I think you'll find most folks here recommend going with OEM (Lemforder) using either 750 or M5 bushings. Urethane squeeks like ...a friend of mine just put an entire eurethane front end in his car (71 Chev Nova) and you can literally hear the thing squeeking down the street.

Re: your 750 bushings gone at 30k...that's a sure sign that the car wasn't sitting fully loaded on its front suspension when the bushings were torqued to the frame. The problem with torquing while the car's on a hoist is that the bushing's strain datum (fancy word for where it starts to bend up and down from) is incorrectly positioned (by about 30-40 degrees from the design position. Once the car is lowered from the lift and the suspension rises to take the full weight of the car's front end, the bushing is now being twisted from it's normal equillibrium position...it's only a question of time before it then fails since it is now spending 99.995% of it's time twisted significantly beyond it's design limit-cycle. I'd go with the 750 bushings again (I'm actually going to be getting M5 bushings, myself) and ensure that the shop does the bushing bolt torque down when the vehicle is resting fully on the ground.

Cheers,
Duey

[Chip]

Jeremy-
Check out Road Race Technologies for their sport control arms and thrust arms. These will at last everything. I'll be putting the thrust arms on my car soon.

http://www.roadracetech.com/

[Mobius]

Has anyone had any experience with urethane bushings for the control arms or thrust arms?

No experience, but I'd recommend against them in the thrust arms. In the control arms, maybe.

The thrust arm bushings need a certain amount of flex in them - if you take this flex out (with a solid urethane bushing) you're transferring all that force to the thrust arm mount and the drag link.

I think it's fine (and cool) for racing and such, but I think if you do it in a daily driver, you're just moving the wear on the TA bushing to other suspension parts.

The lower control arm bushings, though, don't need to move so much. The same argument applies, but I think you could get away with urethane here much better. I don't really see the point, as these bushings don't die as quickly as the TA bushings, and I can't see them affecting handling too much.

[Johntee540]

Have them on my car and the turn in is scary precise. It points exactly where you point it without any correction. Lane changes happen before you can think about them.

My 5 has turned into an M3! - JT

[JeremyT]

Well, the general concensus is what I expected.... I was planning on the Lemforder arms w/ the 750 bushings again.
As far as torquing the arms under load, I am the only only one who ever puts a wrench to my cars; I made sure as I have in the past to lower the car to the ground and actually drove it down the driveway and back (about 1/8 mile) before torquing the bolts for the arms. I guess I've just been driving her a little hard since my 535 has been apart, and the crappy meyle parts just don't hold up. Thanks guys... I'll order the Lemforder arms like I put on the 535.