Inner Axle End Play?

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Jan 29, 2002 | 02:54 PM

tzavaleta

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Racer

Joined: Sep 2000

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From: Austin TX

Inner Axle End Play?

The inner axles on my '74 both have end play. However, 1 was insignificant while the other was noticeable. We opened the rear up and the one with bad play was clear worn. The other didn't appear to be worn at all (it may have been replaced).

So what end-play is acceptable? I've heard 4 to 8 thousandths (.004 - .008). That is such a small amount that it would only be noticeable with a dial indicator right? What is correct? And what is acceptable?

Jan 29, 2002 | 03:18 PM

Smokehouse69

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From: Semper ubi, sub ubi

Cruise-In VI Veteran

Cruise-In VII Veteran

Re: Inner Axle End Play? (tzavaleta)

If you mean the end play of the rear yokes, .004 to .008 would be hard to achieve. That is close! I replaced my slightly worn yokes and still have about at least .03-.04 movement on each of the shafts. This was a big improvement over the 1/4" to 3/8" movement I was getting before the yoke swap!

Jan 29, 2002 | 08:46 PM

lbell101

Melting Slicks

Joined: Nov 2001

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From: Casa Grande AZ

Re: Inner Axle End Play? (tzavaleta)

I don't think there is a real consensus on this. My brand new ones moved about 1/16" - maybe a little less. I believe that's about normal for new ones. My old ones were at about 1/4" and both were very worn with the clip off of one side. Of course I would think smaller is better. But if you don't have access to a surface grinder or mill and a welder then you just can't adjust it. I would think brand new yokes would be produced to the correct tolerances anyway.
I would REALLY like to see a REAL GM tolerance in print for this tolerance.

Jan 30, 2002 | 08:49 AM

mrvette

Team Owner

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From: Orange Park Florida

Re: Inner Axle End Play? (lbell101)

1/16 is relatively ok, but 1/8 is in the danger zone.....
and if the yokes and cross shaft are new, the play should be much less than 1/16 inch.....now in order to get that...you may have to put new posi clutches in...they get worn and allow the side gears to ride toward the outside of the case...moving the yokes ourboard also....giving slop...
now sometimes I have found shims in the clutch packs....I dont know about availability as I managed to combine parts from two rears when I rebuilt mine for a housing defect....long story..

GENE

Jan 30, 2002 | 08:58 AM

norvalwilhelm

Race Director

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From: Waterloo ontario Canada

Re: Inner Axle End Play? (tzavaleta)

I had the problem of too much play so I first checked the hardness of the end of the yoke to determine if the case hardening had been worn through. One was ok so I cut a bigger grove towards the outside to allow 2 clips to be installed. If a clip is .100 then the yoke would be moved in by .100. If the clearance is less then the thickness of a clip move the grove in the direction needed. I ran 2 clips for more then 5 years without any problems. If the yoke is soft on the end it must have a tool steel button installed.
And yes you can get your clearances to almost zero. I had mine so tight I had trouble getting the pin back in.

Jan 30, 2002 | 11:19 AM

GTR1999

Tech Contributor

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From: Connecticut, USA

Re: Inner Axle End Play? (norvalwilhelm)

Norval, do you know what the rockwell is on the end of a good yoke?
this subject generates a lot of interest so I'm gathering information on new,used, and rebuild yokes. I would like to see this info a common reference point, like FAQ's.
Thanks,
Gary

Jan 30, 2002 | 12:11 PM

Tom454

Le Mans Master

Joined: Apr 1999

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From: Raleigh North Carolina

Re: Inner Axle End Play? (gtr1999)

GENE (mrvette)... I have a question... diffs are not my area of expertise, so please bear with me...

How can the posi clutches affect the yoke end play?

The inner tip of the yoke rests on the pinion shaft... so that is how inward movement is governed. The pinion shaft is retained by the differential case (posi case). The diff case is held in place by the differential side bearings.

The yoke clip (which limits outward movement) rests on the differential side gear, which rests on the side gear thrust washer, which rests on the differential side bearing inner race. The differential side gear rollers & outer race are limited in movement by the side bearing cup and the side bearing shim & spacer. I don't see where the posi clutches come into play anywhere in this mess to affect yoke end play.

This is an honset question..... not a wise crack.

Diff Dummy

Jan 30, 2002 | 02:36 PM

norvalwilhelm

Race Director

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From: Waterloo ontario Canada

Re: Inner Axle End Play? (gtr1999)

I don't remember the RC values for my yokes but I would expect it to be in the upper 50s or as high as 62 RC. I know the 01 tool steel buttons are around 60-62. When I tested mine one was high and one in the 40s which is too soft. Hardened axles are around 45RC and I made my new ones 47RC. With the yokes they are only case hardened on the end so machining the grove bigger is not a problem. Besides doing one of my own I did another guys and I never heard back about problems.
So if they check out hard upper 50s or better and the play is excessive have a shop open the grove up to accept 2 clips.
RC is rockwell hardness using a diamond indentor and 150 KG. It is an industrial standard for testing.