I am looking for help on setting the clutch clearance in a 8 inch diff. the only info that I have requires some sort of tool [per mitchell] to check the clearance, I have had no luck finding this tool. Is there a way to check for clearance using a feeler gauge or depth gauge? What should the clearance be? thanks for the help
I checked the manual that I have and the only special tool that you need is a torque wrench adaptor to check the operation of the clutches in the differential unit. You can use a regular torque wrench and check the turning torque of the differential in the following way: jack up one side of the rear end so that it clears the ground. using a torque wrench on a lug nut (so that the wrench is lined up with the center but going to the outside of the wheel) see how much torque it takes to turn the wheel. Write that value down as A=x foot pounds With the torque wrench on a lug nut so that the wrench is across the center point of the axle measure the torque it takes to turn the wheel again. Write that value down as B=x foot pounds. Add A and B and record that value as C Divide C by 2 (C/2=Z) and record that value as Z Z should be at least 40 foot pounds. If it is less than 40 foot pounds the differential unit needs to be rebuilt or shims added to increase the pressure on the linings. Note: This differential assembly is put together with springs that place 1500 pounds of pressure on the clutches. You need a hydraulic press of at lest 1 ton capacity to disassemble and assemble the clutch mechanism of this differential. Personal injury can result from improper disassembly. If you do not have the tools with which to properly do this job leave it to a professional.
What Pauls said is correct,as a guy that does this for a living,here is what I've learned(or done)for years,take the ring gear off the Trac-Loc,remove the 2 philip screws,tap the 2 halves apart with brass hammer,there is square "clip"that covers 4 spings,slide it off and the 4 springs will fall out,put the 2 halves back together and either bolt and nut together in a few places or bolt ring gear on with 4 bolts,stick axle in side posi on the side with 2 side gears(right side)and engage only the outer splined side gear,you should be able to hold assembly and turn axle without a lot of force,here comes the fun part,take everythinp apart again,on the side with the clutches,remove clutch pack(keep track of order)at the bottom of the clutch stack is a shim approx.1/2 wide,4-5" dia.,you want to add .005 of shim,reassemble everything(with out springs again)try and turn axle again,when you have just enough drag on clutches it won't turn,disassemble again and add.010 more than the no drag "clearance"you will have a nice "tight"Trac-Loc"it will usually only chatter slightly going around corner,Note:Should replace clutches if worn before doing this procedure,soak, in Ford SVO posi additive before installing new clutches,get your no turn clearance,then shim as explained,use posi additive in rear,if clearance set too tight it will chatter a lot and wear out clutches quickly,this will work on all post '70 8'or9' Trac-Locs...Good Luck
ActionRPM, When you separate the halves of the differential do the bolts release the pressure before they reach the end of their threads or do you need to hold it in a press while you remove the bolts?
The two philip head screws hold the halves together,when released on a Trac-Loc there is only about 1/8'' of preasure,you really won't even notice it,on other type posi's there is some major spring preasure but not these.
