Hey guys, you helped me out a couple of weeks ago, with some questions on a Traction Loc rebuild.

Well, I have the carrier apart, and I ordered new clutches and the S spring. My question is: How do I go about checking the backlash? Zee, you said you used an indicator, what exactly do you mean? Otherwise, this does seem to be a pretty straight forward job. Thanks for the help.

I found this web site the other day
9 inch Rebuild (http://www.fnc.ch/Technik/9-Inch_rebuild.htm)
shows how to check backlash and has a good pattern diagram also. I assume since you said trac-loc your talking ford.

Ryan,

Thanks, but I've got an 8.5" GM corporate posi unit, I thought they were also called Traction Loc, but I may be wrong. Anyway, its the GM unit with the S shaped spring in the middle.

Thanks again.

GM used the Traction Lock in the 8.5 instead of the Eaton that was used in the 12 bolt and 8.2 10 bolt. Zee was using a dial indicator on the pinion gear to check the preload on the clutch plates. If the plates are not shimed tight enough there will be backlash on the pinion and axle gears. I do it a different way. I just shim the plates untill I can barely get the thrust washers behind the pinion gears. You can also get it tighter by using a short bolt and nut between the axle gears to push the axle gears apart. This allows you to get the thrust washers behind the pinion gears with more preload on the clutches. The more preload you get the better it will lock up, but you will get more popping when turning tight corners. Did you get any shims for the clutch plates? You will need them to set the preload on the clutches.

BGH,

OK, I think I've got it. I'll try anyway, I like your method...keep it simple.

I didn't get any shims, the ones in the carrier were marked 094, which I assume is their width. I figure, if I need thicker, I'll go to a machine shop like Zee did.

Thanks again.

One thing I forgot to mention. When you get the clutches and gears in the case you should look throuth the holes where the cross shaft goes and see if the pinion gears are lined up with the holes. If the clutches or shims are too thick on one side or too thin the pinion gears will be offset to one side or the other. You may need to put a little more shim on one side to get the gears lined up with the holes.