Question regarding bushing holders

[Yves40]

Hello,

I have a question regarding the use of a split housing as a bushing holder in an automotive control arm application. Is there any reason why this is not used. This would solve a lot of issues with dis/reassembly.

Thanks

 

[NormPeterson]

More pieces?

More steps at final assembly?

Consequences of fastener loosening/breakage?


Norm

 

[izzmus]

I'm unsure as to what "issues" there are, myself. The old ones press out, the new ones press in.

 

[GregLocock]

Depends on the bush in question. Typically those in the steering loop might have a rate greater than 10000 N/mm, it would be very difficult (but not impossible) to design a split housing that was just as stiff as that, which would reduce the effective bush stiffness to 5000. Another example of this is the D block on a sta bar, these used to be 1000 N/mm or so, and were located in a U shaped clamp pressed from steel, with a couple of bolts. Modern ones might be 5000 N/mm and their effective installed stiffness is a function of their clamping system as much as the bush itself.






Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[Yves40]

The bushings i refer to are for A-arms with a shaft through the bushings and in the A. This shaft mounts the A-arms to the chassis.

Basically a good design, but to properly press the bushing out and in, the shaft is always in the way. A lot of arms get bent.

I'm investigating this, because i'm going to change from rubber to solids. With the original rubber bushings, most just burn out the rubber to avoid bending the arms. With solids of course this is impossible.

Thanks

 

[izzmus]

With the proper fixturing, there is no issue.

 

[Yves40]

What do you exactly mean with the proper fixture ?

 

[BrianPetersen]

He means the proper tooling with which to press the bushing in and out correctly without putting the stress on the arm itself.

 

[Tmoose]

Here is how the factory service manual suggested doing it in 1974

 

[GregLocock]

Yes, or as Triumph motorcycle manuals used to say, "reassembly is the reverse sequence and should give the experienced mechanic no trouble".

Hacks on the other end will bend the arms because they are too lazy to make up appropriate spacers.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[Tmoose]

"The bushings i refer to are for A-arms with a shaft through the bushings and in the A. This shaft mounts the A-arms to the chassis.
Basically a good design, but to properly press the bushing out and in, the shaft is always in the way. A lot of arms get bent.
I'm investigating this, because i'm going to change from rubber to solids. With the original rubber bushings, most just burn out the rubber to avoid bending the arms. With solids of course this is impossible."
======================================================

John Greenwood

http://www.racingsportscars.com/driver/photo/John-Greenwood-USA.html

7 top 10 finishes with 5 firsts in class and 3 first overall. Won the class at Sebring in 1971 with Dick Smothers co-driving.

5 first grid positions earned by setting quickest qualifying lap.
Using 7 liter (427) engine or larger.

His 1986 comments about C3 Corvette front control arm bushings are captured in the attached image.

 

[tensor47]

Slightly off topic, sorry.
Greg, in FAQ you have a free SLA software package SLARK listed but the site no longer exists.
I would like to try it out rather than use a very long piece of paper as in '67.
A year later the Lotus 49B came out with very similar wishbone lengths especially at the rear.
Can you advise how I can receive a copy.
I am again designing/building a small hill climb car, this time with Yam 1000 and 4wd.
Cheers
John

 

[GregLocock]

http://www.v8mongrel.com/_i/slarck.xls

I'm sure they asked my permission!

You need to set iteration /on/ in the tools/options/calculations tab

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?