Rear wheel play ?
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Good advice although I like to see the stub axles at less than 060. Remember that whatever play you have in the stub axles translates to about twice as much movement at the top of the tire. 1/8" of movement at top of the tire as quite a bit and will probably feel bad when doing quick left/right transitions as the rear wheel flops around.
Also recently learned for another reason of excessive stub axle play, besides the stub axles being worn: If the posi clutches in the diff are worn stub axles can move out more. The stub axles are held in place in the outward direction by the spider gears, and the posi clutches are between the spider gears and the carrier. Worn posi clutches=thinner=spider gear sits closer to the carrier=more stub axle play.
Ideally you'd like to see stub axle play of 0.005".
Also recently learned for another reason of excessive stub axle play, besides the stub axles being worn: If the posi clutches in the diff are worn stub axles can move out more. The stub axles are held in place in the outward direction by the spider gears, and the posi clutches are between the spider gears and the carrier. Worn posi clutches=thinner=spider gear sits closer to the carrier=more stub axle play.
Ideally you'd like to see stub axle play of 0.005".
Thread Starter
Banned Scam/Spammer
Joined: May 2003
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Well, maybe I shouldn't have said "end play". What I want to know if I rock the wheel in the 12:00/6:00 postion, how much movement should I have. It apears all the movement is coming from the trailing arm/frame kick-up area. About 1/8" at the outer tire diameter which is about 27" OD.
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
70vert: Movement in the 6/12 position is not trailing arm although it may look like it. Look carefully at the stub axle that goes into the diff as you are rocking the wheel. I bet you will see it move in and out. Also looking under the car at the strut rod while someone else rocks the wheel you can often find quite a bit of play in the strut rod if the bushings are shot.
On mine a previous owner had installed poly bushings in the strut rods and they were totally shot. I could pull the strut rod 1/8" in and out.
On mine a previous owner had installed poly bushings in the strut rods and they were totally shot. I could pull the strut rod 1/8" in and out.
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Also, if you are seeing 1/8" movement at the top of the tire I'd call it borderline. Yes, it's a good idea to fix it, but it is not absolutely necessary.
The above assumes not all of this play is in the wheel bearings as that would have to be fixed, but rather some play in the bearings+stub axle. Also make sure you have absolutely no play whatsoever in the U-joints. Any play there means replacement before something bad happens.
The above assumes not all of this play is in the wheel bearings as that would have to be fixed, but rather some play in the bearings+stub axle. Also make sure you have absolutely no play whatsoever in the U-joints. Any play there means replacement before something bad happens.
Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
Several weeks ago I realized I had about 1/16" rock on both sides at the 12/6 position.......it was actually a tad more on one side. After checking bushings and such I pulled the halfshafts loose and with someone rocking the wheel I could see the spindle flange rocking up and down. After checking end play at .008" I decided to go ahead and replace the bearings. Once I pulled everything apart I made a set-up tool, cleaned the old bearings and races (washed the grease out) and did a "dry" check. This time I got .011". I just did my final dry check tonight with new brgs. and shim at .0015". Hope to grease and assemble it this weekend.
Want to thank Gary (gtr1999) for sharing his knowledge on this project. BTW Gary.....I've got an interesting story concerning the seating of the outer races to the bearing housing face.....
Want to thank Gary (gtr1999) for sharing his knowledge on this project. BTW Gary.....I've got an interesting story concerning the seating of the outer races to the bearing housing face.....
Last edited by goinbroke; Sep 1, 2004 at 10:34 PM.
Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
Gary....kind of a strange deal. When I went to knock the old races out I thought I could see that the inner wasn't fully seated against the shoulder. I cleaned everything out real good and installed the new races and the inner still wouldn't seat all the way. I could get a .015" feeler between the race and the shoulder. Hmmmm....knocked the race out again and had a close look. It seems that when the housing was machined there was a step left on the face just above the radius (where the bore and face meet). The only solution I could come up with was to enlarge the radius on the corner of the race to clear the step. I changed it from about a 1/16 rad. to maybe 3/32. Once it seated up all the way I did another dry endplay check. This time it was .029".....(my first dry check was .011"). I made a new shim to get the the .0015" so I think I'm good to go. I just thought it odd that this thing has basically been seating up on that tiny area all this time.
Burning Brakes
Joined: Jun 2002
Posts: 837
Likes: 3
From: Texas
Gary...not sure what you mean by bore stepped or flashing??? But.....I agree.....001 to .002 endplay seems to be what most people recommend these days.
...and yes ......my apologies also to 70vert for letting your post wander off like this. To your question.....1/8" rock at the 12/6 position would be something to look into....just my opinion. I'd check everything that zwede and Gary suggested.
...and yes ......my apologies also to 70vert for letting your post wander off like this. To your question.....1/8" rock at the 12/6 position would be something to look into....just my opinion. I'd check everything that zwede and Gary suggested.
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Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
Could also be worn/dry ujoints. Movement of 1/8" and over
at the wheel should be noticable when underneath and a helper
wiggling the tire. It could be everything has a little play.
If you can't see what is loose and moving, you should be OK for
now. Keep an eye on it.
at the wheel should be noticable when underneath and a helper
wiggling the tire. It could be everything has a little play.
If you can't see what is loose and moving, you should be OK for
now. Keep an eye on it.
