[Shop-talk] tolerancing a interference or friction fit ???``

[Eric J Russell]

Will it help to freeze the bushings before inserting them?

Eric Russell
Mebane, NC
http://home.mebtel.net/~ejrussell
----- Original Message ----- 
From: "john niolon" <jniolon at bham.rr.com>
To: "shop-talk" <shop-talk at autox.team.net>
Sent: Thursday, April 08, 2010 11:13 AM
Subject: [Shop-talk] tolerancing a interference or friction fit ???``


> I'm still trying to press in some steel sleeved bushings into tubular 
> control
> arms for a front suspension I'm doing on my old truck.  Having a devil of 
> a
> time.  I'm about to think that the bushings are just too large.   Tried a 
> 6
> ton press and it just stalled...  had some luck with a bolt/nut/impact but 
> it
> easily destroys the bushing rubbers if it's not perfect...
>
> the control arm bore is mic'ing 1.250 +/- .002   the bushings are anywhere
> from 1.260 to 1.268.  No two measure the same.  It's a steel sleeve with
> rubber core over a inner steel sleeve that the suspension bolt slides
> through.
>
> I'm wondering what a 'friction' fit tolerance should be ??? I'm no 
> millwright
> or machinist and  I know the application/metal type/use makes a difference 
> but
> are there some general guidelines that would apply...  everything I find 
> on
> the net is in engineerspeak and symbols and alchemy/sorcery stuff...
>
> what would be considered an exceptable friction fit for suspension 
> bushings...
> .001 to . 003  ??  .015 >??  I haven't got a clue..  help me oh gurus of 
> the
> metal melding !!!!!
>
> I've already had to cut out two bushings that hung up on me... there has 
> got
> to be a better way... I'm just not smart enough to know it.. and yes
> everything is slippery as owl snot before I start trying to press them 
> in...
>
> tia
> John