How much play is 'OK'?

[72Charger-SE]

Vehicle: 1972 Dodge Charger SE
Rear End: 8 3/4 - 3.55

I replaced the rear end in my car with a sure grip 8 3/4 with 3.55 gears.  In doing so, I moved the axles from the original rear end in my 72 Charger (8 1/4, I believe) to the 8 3/4 rear end.  I seem to have a lot of 'play' when pulling on the wheels (to the side) once the tires are mounted.  How much 'play' is too much?  I am estimating I have 1/4" of play or so.  That seems like a lot to me??  I replaced all the wheel studs with new and have them properly seated against the hub.   The entire assembly is moving (hub, wheel, drum). 

[mopar0166]

Thats way to much play ,and why are you using 81/4 axles ona 83/4 rear? 

If you need axles PM, hopefully your some what local

[Nacho-RT74]

manuals says the axle play must be 0.008 on a 8 3/4"

must use the correct axles. diff axles can't be used. They fit, install and work totally diff from the rest

[chargd72]

I moved the axles from the original rear end in my 72 Charger (8 1/4, I believe) to the 8 3/4 rear end. 

Not swappable!!!

[72Charger-SE]

Ok... so the reason I am using 8 1/4" axles on an 8 3/4" rear end is I didn't know not to.    I will get the correct axles and that will solve my problem.  

I am glad I asked now so as not to damage anything.  So far all I have done is tow the car 40 miles on a two wheel dolly for some metal work and to shoot it with a primer for protection.  

I am in Iowa (not sure if that is local to you or not)?

Thanks.

[mopar0166]

Yeah im in jersey, but if you are stuck and cant find some ill look into shipping them out. 

[Pete in NH]

I think I would also install new wheel bearings and seals on those axles while I had it apart. We had several vehicles in the family over the years with the 8-3/4 rear and those bearings where kind of a problem area. I just put new ones in my 71 a few years ago.

[ralley72]

FYI, A person told me about a 71 Charger 500 sitting in a pick and pull yard in or around Sioux City Iowa. He pulled some parts off it a week ago, has a 383 with a 8 3/4 rear end. If your close to that area, it might worth the time to get that rear end.

Mike

[72Charger-SE]

Thanks Everyone...

So, the next question...  by looking at an axle...  how can I tell if it is for an 8 3/4 or 8 1/4 rear end?   Are there specific 'sides' or can the be used on either side?

Thanks!

[chargd72]

An 8.25 axle will have 27 or 29 spines and is held in to the carrier with a C-clip.  An 8.75 axle has 30 splines and is locked in at the housing ends.

[72Charger-SE]

This is the only pic I can find of when I was putting it back together.  Can you tell the axles are wrong by this picture?  I really don't remember which axles I used however the slop in the rear end makes me think I used the wrong ones...

[cdr]

you might have the correct axles,but ether you did not adjust the axle bearing adjuster,or you dont have the buttons in the differential that work to set the axle end play with the adjuster. those look to be the correct axles

[72Charger-SE]

you might have the correct axles,but ether you did not adjust the axle bearing adjuster,or you dont have the buttons in the differential that work to set the axle end play with the adjuster. those look to be the correct axles

Ok... with that said, what do you recommend my next steps should be?  Pull the axle off one side and verify 30 splines and?? 

[cdr]

pull the axle & look inside you should see this button down in the cross pin area and count the splines

[cdr]

axle adjuster

[72Charger-SE]

Ok.  Will do.   Probably not for a week or so.  Tomorrow is 'welding' day for the rotisserie 're design'.   Thanks!

[Cooter]

Cdr is correct. Anytime you swap around centers, especially with a sure grip unit, you MUST re adjust the axle end play.
If as with many sure grip units, someone has lost the thrust button/block (thingy inside the splines in sure grip unit between axles) you will NEVER get it right. See, the axle end play is adjusted all through one side, so the axles have to have that button in the center where tgey meet in the sure grip unit as one pushes on the other to set BOTH axles at once...

[72Charger-SE]

Wooohoo!!  The tightening of the axles with the adjuster resolved the extra play issue.  Thanks to all!!