Bal l Joint Play

[justin brady1]

Quick question...

How much vertical play is allowable in the ball joints? I was polishing wheels and wanted to check them so I placed a 2x4 under the wheel and lifted.
There's a pretty significant amount of play there and an audible movement.
I thought for sure they needed replacement, but I read this:
http://vintage.mitchell1.com/PClubData/chassis/chts77/V2D7711012.pdf
And it says movement up to .125" is fine.

What says the community?
--
Justin Brady
http://www.thegmcrv.com/
1976 Palm Beach 455

 

[Ken H.]

Justing,

Check the X-7475 manual for the ball joint checking procedure. Your method
sounds very much like that used by a local "alignment shop" many years back
when I took the GMC with them with brand new ball joints. They declared
them worn out. I checked them IAW the the manual and found them
"perfect". I haven't been back there.

Ken H.

> Quick question...
>
> How much vertical play is allowable in the ball joints? I was polishing
> wheels and wanted to check them so I placed a 2x4 under the wheel and
> lifted.
> There's a pretty significant amount of play there and an audible movement.
> I thought for sure they needed replacement, but I read this:
> http://vintage.mitchell1.com/PClubData/chassis/chts77/V2D7711012.pdf
> And it says movement up to .125" is fine.
>
> What says the community?
> --
> Justin Brady
> http://www.thegmcrv.com/
> 1976 Palm Beach 455
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[terry1]

Justin, that procedure you linked to is erroneous because it does not take into account any play in the wheel bearing and in fact is probably going to
show wheel bearing play before showing ball joint play. At least that's the way I read it.

I check ball joints by taking the suspension loading out of the system while still trying to maintain the same angles in the components. Sometimes you
have to jack from inconvenient points.Use a pry bar under the tire on the GMC after you raise it off the ground by jacking on the lower control arm as
far out as you can get.You can use vice grips and dial indicators if you want, but there should be no up and down movement in the ball joint. This
test may also show wheel bearing play, but you will be able to see both sources of looseness if you have a helper on the pry bar or a long arm.

Use pry bars and large plastic hammers to amplify what piddly forces a human can put on a suspension system, compared to the forces from driving down
most roads. You might be surprised what is loose down there if you just raise one tire just off the ground and start hitting it side to side with that
large plastic mallet!
--
Terry Kelpien

ASE Master Technician

73 Glacier 260

Smithfield, Va.

 

[jim kanomata1]

My understanding of the lower Ball joint is that the load of the coach
applies the pressure on it and i remains centered so I know on my two
coaches, I just keep them lubed and live with a 1/4 " vertical play.
However the top joint is more susceptible to horizontal movement and the
tolerance must be followed.

> Quick question...
>
> How much vertical play is allowable in the ball joints? I was polishing
> wheels and wanted to check them so I placed a 2x4 under the wheel and
> lifted.
> There's a pretty significant amount of play there and an audible movement.
> I thought for sure they needed replacement, but I read this:
> http://vintage.mitchell1.com/PClubData/chassis/chts77/V2D7711012.pdf
> And it says movement up to .125" is fine.
>
> What says the community?
> --
> Justin Brady
> http://www.thegmcrv.com/
> 1976 Palm Beach 455
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502

 

[john r. lebetski]

We assume you mean the lowers??? The lower is the load bearing joint so the slop is removing by the loading of the ball and socket-- until it fails.
However on washboard roads or under heavy braking or maneuvering that play can come into effect and cause sudden alignment geometry changes. You need
to jack inder the lower arm to take the lower loading off the joint, then check for play by prying as others have mentioned. My thumbnail guide is
any more than 1/8" is due for replacement because new ones cannot even be moved by hand. The Rob Mueller writeup is your best bet for checking front
end parts and a helper is needed to opperate steering to complete the tests.
--
John Lebetski
Woodstock, IL
77 Eleganza II