Posted By: Anonymous
how to tell if its a sure grip or not - 05/29/11 12:09 PM
looking at an 8 3/4 742 case to buy. supposed to be 3:55 gears. is there a way to tell if its one wheel drive or two? anyway to check ratio also? Thanks
how to tell if its a sure grip or not
Posted By: MoparforLife
Re: how to tell if its a sure grip or not - 05/29/11 12:52 PM
If it is in a car or truck - Jack up the rear of the car and turn one wheel - If the other side turns the same way the same speed it is a sure grip, if you turn one wheel and the other don't turn or the other rotates the opposite direction it is not a sure grip 
If it isn't in a veicle ook at this. http://www.moparts.org/Tech/Archive/axle/13.html
If it isn't in a veicle ook at this. http://www.moparts.org/Tech/Archive/axle/13.html
Posted By: Kern Dog
Re: how to tell if its a sure grip or not - 05/29/11 03:15 PM
It appears that the case will be OUT of the axle housing.
The 2 types of SG differentials were the Dana power Lock and the Auburn. Each is unique. The Dana is the preferred because it is easily rebuildable.
Nevertheless... the quickest way to determine if it is a SG diff: The OPEN/One legger unit has large openings where the spider gears are visible. You can fit your fingers in and easily touch the center pin as well. The SG diffs have much smaller openings.
The 2 types of SG differentials were the Dana power Lock and the Auburn. Each is unique. The Dana is the preferred because it is easily rebuildable.
Nevertheless... the quickest way to determine if it is a SG diff: The OPEN/One legger unit has large openings where the spider gears are visible. You can fit your fingers in and easily touch the center pin as well. The SG diffs have much smaller openings.
Posted By: RapidRobert
Re: how to tell if its a sure grip or not - 05/29/11 03:20 PM
Quote:The 3rd mem is out on the ground correct? Count the teeth on the pinion and the ring gear and divide the small # (pinion) into the large # (ring)
anyway to check ratio also?
Posted By: scratchnfotraction
Re: how to tell if its a sure grip or not - 05/29/11 03:26 PM
the yr and ratio are stamped into the edge of the ring gear on 8 3/4
if its out just turn it to see the stampings
if its in the car jack up one side and turn the tire..if it turns its a pegleg
if you cant turn it its a sg that is holding
if its a sg and after checking one side off the ground,then jack up the other side to check it to see if it holds
should not be able to slip it by hand with tire on
I have seen one side weak cause a smaller tire ran on one side for a while
i have seen sg worn so bad that you can turn it by hand like an open diff
if its out of the housing stick both axle in it and see if you can slip it by hand to check if its holding
if its out just turn it to see the stampings
if its in the car jack up one side and turn the tire..if it turns its a pegleg
if you cant turn it its a sg that is holding
if its a sg and after checking one side off the ground,then jack up the other side to check it to see if it holds
should not be able to slip it by hand with tire on
I have seen one side weak cause a smaller tire ran on one side for a while
i have seen sg worn so bad that you can turn it by hand like an open diff
if its out of the housing stick both axle in it and see if you can slip it by hand to check if its holding
Posted By: 63stabamatic
Re: how to tell if its a sure grip or not - 05/29/11 04:40 PM
Good info. Another way I've seen is to turn the driveshaft input. If both wheels turn the same way it's a SG.
Posted By: RobX4406
Re: how to tell if its a sure grip or not - 05/29/11 06:49 PM
Clutch style
Cone style
Note location of bolts holding two halves together on clutch style, opposite side of the ring gear. Cone they are on the same side as the ring gear bolts.
Cone style
Note location of bolts holding two halves together on clutch style, opposite side of the ring gear. Cone they are on the same side as the ring gear bolts.
Posted By: Anonymous
Re: how to tell if its a sure grip or not - 05/30/11 07:53 PM
really appreciate all the help.