mopar sure grip rear diff ?
 

I have a 73 challenger and do not know if it is a sure grip or not please advise thanks:confused:

sam, just jack up the rear end and with the tranny in neutral turn one of the back tires.If the other side turns in the same direction,it could be a suregrip,locker,or spool.If it turns the other direction it's an open rear end.

john

..............or just jack up one wheel, leave the car in neutral, make sure the parking brake is released

If you can turn the wheel, it's an "open" rear


If you can't turn it, it's sure grip/ spool, etc, as above

Um, I thought if its an "open" rear, the other wheel would spin in the opposite direction. If you just jack-up one, it wont spin at all. If you get under there, look for numbers, or tags on the diff also. Might help to find your ratio also.

X2

Sorry guys,but 440RR is right. He did say "to have the tranny in neutral". I also agree with you on the looking for any tags.

You can actually perform this with the car in park. If the diff does have some sort of locking device that is in proper working order (sure grip, spool, locker, etc.), then neither of the tires will spin. If the diff is open (has spider gears in it only), then the tires will spin (one forward, one backwards) as the spider gears have the ability to spin freely from the carrier/R+P. The axle shafts slide into the side gears which in turn are "connected" by the spider gears that are being held in place by the carrier pin.

I know this works even with a sure grip that is completely worn out as Heathers' brother's truck is like this (just looked at it for a rear end noise yesterday and spun both back tires with the truck in park).

Yup. has to be in neutral, emergency brake off.

I just thought this might be quicker and easier

On a side note, if you DO jack up one side and the wheel DOES turn, remember this when looking for the ratio:

One an "open" axle, with one wheel up and the other down, the spiders multiply X2

So if you are trying to determine the ratio, you turn the wheel TWO full turns while counting driveshaft revolutions.

Obviously with a sure G/ locker/ etc, you have to have both wheels "up" and count just one turn of the wheels for the shaft ratio