‘66 charger rear end

[Wimpykidz21]

haven’t done much reach yet I will when I get home. I’m at the shop now so it’s easier to post pictures. If your able to provide any information as to what I have let me know. I want to make it a sure grip what’s the correct process of doing so

 

[Wimpykidz21]

Here is another picture

 

[beanhead]

'741' casting 8-3/4" rear. Small '7260' series yoke and u-joint, more than likely an open differential. Rotate the yoke and count how many turns it makes for the wheel to make one full turn, that's the gear ratio. (For example if the yoke makes 2 and three quarter turns to one turn of the big gear you have a 2.76 ratio). Spin one wheel forward, if the other wheel spins forward also it's got a sure grip differential otherwise it's a peg-leg, not so good for high-performance...

 

[Wimpykidz21]

It’s an open for sure. I don’t think it’s limited slip either that’s why I asked about the correct process to make it “sure grip” or similar

 

[Fran Blacker]

If third member has never been removed gear ratio tag might on the stud at 1 o'clock facing it.

 

[beanhead]

As far as making it a sure grip, a Factory Service Manual is a must-have...It will show you the disassembly/installation procedures and torque values. You'll need to get a sure-grip unit and might as well get an install kit with new bearings etc...just a matter of changing parts and setup at that point. Details are in the manual
http://www.mymopar.com/index.php?pid=109

 

[PurpleBeeper]

Hey Whimpy, the information about sure-grip/non-sure-grip & gear ratio is all good info. To answer your question about how to turn your rear end into sure-grip:
1. Determine what gear ratio you want to run....your choices are 2.76, 2.95, 3.23, 3.55, 3.91, 4.10 (stock optional gears).
2. Locate a sure-grip center section (aka "chunk" aka "pumpkin") that already the gear ratio you want. You can use a "741", "742", or "489" center section (last three digits of the part number stamped on the side of it...like your current "741"). All three of these center sections come both "sure-grip" & "non-sure-grip" (aka "open"). You should look at some online pictures, but basically, sure-grip center sections differentials look "mainly closed with some holes" & not sure-grip center sections look "more open with several 2"-3" diameter round (spider) gears obviously visible".
3. Determine if you have the "small" u-joint or the "big" u-joint now. Either size is fine. If you end up with a mis-match between the driveshaft & the front yoke on the center section, there are also big/small conversion u-joints readily available.
4. Get a 8-3/4" gear change gasket kit (from Dr.Diff or similar), 2-3 quarts gear lube, small bottle of Ford (yes, Ford) limited-slip additive.
5. Install new sure-grip gears per factory service manual....consider new axle bearing & at least inspect/clean/re-pack them.
I'd rate this a "medium difficulty" project...time consuming, but not that tough.

 

[Wimpykidz21]

Hey Whimpy, the information about sure-grip/non-sure-grip & gear ratio is all good info. To answer your question about how to turn your rear end into sure-grip:
1. Determine what gear ratio you want to run....your choices are 2.76, 2.95, 3.23, 3.55, 3.91, 4.10 (stock optional gears).
2. Locate a sure-grip center section (aka "chunk" aka "pumpkin") that already the gear ratio you want. You can use a "741", "742", or "489" center section (last three digits of the part number stamped on the side of it...like your current "741"). All three of these center sections come both "sure-grip" & "non-sure-grip" (aka "open"). You should look at some online pictures, but basically, sure-grip center sections differentials look "mainly closed with some holes" & not sure-grip center sections look "more open with several 2"-3" diameter round (spider) gears obviously visible".
3. Determine if you have the "small" u-joint or the "big" u-joint now. Either size is fine. If you end up with a mis-match between the driveshaft & the front yoke on the center section, there are also big/small conversion u-joints readily available.
4. Get a 8-3/4" gear change gasket kit (from Dr.Diff or similar), 2-3 quarts gear lube, small bottle of Ford (yes, Ford) limited-slip additive.
5. Install new sure-grip gears per factory service manual....consider new axle bearing & at least inspect/clean/re-pack them.
I'd rate this a "medium difficulty" project...time consuming, but not that tough.

Thanks for the information I will have to do some research when I get home I sorta understand but I don’t think I follow completely

 

[beanhead]

To me...and this is just me, but the hardest parts are getting the dang center section off the car, removal/installation of the carrier bearings(a press makes this easier) and getting the dang center section hung back on on the car...it's a heavy awkward sumbitch...'course that's me by myself on my back doing it, if you have a lift and/or a helper it's not as bad. There are some fine points to pay attention to (bearing preload/sideplay etc) which are covered in the manual, follow it closely you'll do fine..

 

[Fran Blacker]

I work alone except brake bleeding or heavy lifting, no lift. I pull the whole rear 2 hours max. Seen a rig on here that looks like a 2 U's laid on its side connected together. It has pipe coming out the bottom of that fits into hole of floor jack swivel hole. Top is drilled so it bolts to where pinion snubber goes. If I pulled center sections yearly I'd build one. Maybe the member who build one will post a photo. He made it out of what looked like 2" angle iron, real nice setup.

Edit: I have a small 1 hp compressor to run a cheapo air impact gun. Use it on lug nuts and u-bolts and shock bolts.

 

[YY1]

A 2.94 ratio was super common in 66.