Educate me on rear ends and axles

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coffeedart67

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Planning on going to a auction sale next weekend, the sale bill doesn't list the parts, but there is a picture of a pallet of rear ends(sale is heavy on Mopars). Thinking I may luck out and find a 8 1/4 a-body rear. I printed off the charts to identify rear by case and widths. One question I have is flange to flange measurement is that without brake backing plates? One other question is what casting numbers accomadate what ratios? I would like to stick with highway gears. Also axle identification, lengths, and iding for different rears & bodies. I want to go prepared so I know what I am looking at. Will check over my Mopar Performance books also.
My 7 1/4 (67 Dart 273 auto)is howling, so I'm thinking an upgrade is in the future.
Thanks
Aaron
 
I have a A-body 8.25 with 2.45 highway gears id part with very reasonablely. pm if intrested.
 
OK in reading through my Mopar Perofrmance Chasis book, I have 2 questions:1. any 8 1/4 housing will take any gear ratio as long as you have the correct carrier. correct? 2. Did the 8 1/4 replace the 8 3/4 or is there such a thing as a BBP 8 3/4 for the a-body?
Aaron
 
If I could find a rear end like that to put in my Dart I wouldn't care if it had an axle. Actually wouldn't rear differential be more accurate for the 2nd picture. Wouldn't the axle be the part with the splines on one end and the studs n the other end.
 
coffeedart67 said:
If I could find a rear end like that to put in my Dart I wouldn't care if it had an axle. Actually wouldn't rear differential be more accurate for the 2nd picture. Wouldn't the axle be the part with the splines on one end and the studs n the other end.
Click to expand...

Best of luck finding a rear end like that.:blob::blob: LOL you have me on the rear diff. I for some reason had something else on my mind. Hope you get your questions answered by someone not so smart assish!
 
A-body center to center on the spring perch mounting holes is 43". The 8 1/4 replaced the 8 3/4 in the A-body in 1973. And no they never made a 8 3/4 with big bolt pattern in an A- body.
 
OK,so I got another 7 1/4, and have a few questions. It has 9" brakes, my 10 brakes and backing plates will bolt right on, correct? What do I check so I am not going through all of this work to end up with the same thing? What parts should I replace? Seals,bearings?
Thanks
Aaron
 
Unless you have a slant six and NEVER plan to 'rod' the thing I would not waste 5 seconds with a 7 1/4 axle. As a 65 year old who actually hopes to make it to 66 in a couple of months, this comes from a "few years" of bad experiences LOL

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your backing plates and brakes should swap across.... As far as howling, if your gears are setup wrong, it will howl, bad bearings somewhere can also make it howl... I wold pull the axles out and spin the pinion and see how smooth it turns. You can pop the carrier out and see how the carrier bearings look, then turn the pinion and see how smooth it turns. Also, before you do anything to it, look around the pinion and backing places for any signs of fluid leaks. If the pinion is not leaking and bearings feel fine, I would not disturb them.

EDIT - just read your last post (posted while I was writing this) If you are replacing it anyway, just put your temporary replacement in and run it. You may want to change your rear brakes but, if they are in working order, it may be just fine as-is.
 
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