7 1/4 worth rebuilding?

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moparmucelli

moparmucelli

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hi guys I was wondering if it worth rebuilding my 7 1/4 differential it is an open diff with 276 gears it's making a humming noise while driving it it's in my 1970 Plymouth duster with a stock 360 727 trans and if it is worth rebuilding can I put the bigger bolt pattern axles in it? And can I convert it to posi?
 
8.25 or 8 3/4 would be better. More parts, better gear selection available
 
On a budget I would ask around probably find 2 or 3 that people will give you as a R&R not very desirable. ALso as you are learning won't live long behind your combo.
 
Understandable, the 8.25 will be cheaper and they did come in a bodies factory. Will have to have your driveshaft shortened with either axle swap. The 7.25 has a 2.5" axle tube, the 8.25 and 8 3/4 are 3" tubes, so different u-bolts to clamp it to the leafs and shock mount pads are needed. Different shock mount pads or slot the holes in the ones you have for the 3" u-bolts. 8.25" axles did come with 3.23:1 or 3.55:1 limited slips if optioned. If you find one in a salvage already removed or in a parts car, check the cover for a tag that is on one of the bolts to the cover. they often have the ratio stamped on the tag, spin of the axles and see if the opposite axle spins the same direction for a limited slip
 
I wouldnt spend the $ on the 7-1/4 if it needs a rebuild. If you were closer, I'd sell you one of mine, 7-1/4 or 8-1/4. Better to find a good one locally.
 
moparmucelli said:
I'm in cali
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I have a 7-1/4" that I just pulled out of my 70 Swinger this weekend that I was planning on taking to the scrap yard.

It's yours for free if you want to come down to San Diego and take it. Nothing wrong with it, was running just fine. I just wasn't planning on using it with my new setup.

Send me a PM if interested.
 
Ok I will let you know when I can come down and everything internally is ok? No noises or anything?
 
Is there anyway I can change the axles in a 7 1/4 from the small bolt pattern to the big bolt pattern?
 
Again, nothing wrong with the unit. Keep in mind that it was behind a slant 6 when i was running it, so I can't guarantee the performance of it behind a 360.

Not sure I'd consider going big bolt unless you already have big bolt pattern wheels/brakes lying around but that would be your call.

FYI - I don't plan on sitting on this for too long as I was planning on taking it to the scrap yard this week. That being said, the sooner you can come down and get it, the better.
 
Budget friendly is always great but if you have time and patience find an 8 1/4. BBP and will easily meet your needs. Going the 7 1/4 route in regards to rebuilding is just not money well spent IMO unless you have a specific reason....

Good luck,
JW
 
moparmucelli said:
Does anybody have a 8 1/4 for sale out there in cali[/QUOTE

Searchtempest is a good start. They often get kicked to the wayside because they are weak (yeah, right.....) Someone like you can swoop in and get a great rear on the cheap....

JW
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7.25 sure grips center sections can be hard to find and pricey. To rebuild it you'll need one of the long spanner wrenches to release the sleeves from the center member. By the time you buy the parts/tools and put the effort into rebuilding it you can get a 8.25. I got mine from a fellow member for 400 bucks complete with a suregrip and 3.23 gears. I've been beating the **** outta it and I haven't been able to break it just yet.
 
8.25 with a SG,done Edit and you will be golden..
To recap;
It already comes with 4.5bc, and 10 x 2 brakes,
remember 3 inch tubes so you will want the bigger U-bolts and matching shock-plates ,
and the driveshaft will need to be shortened.
I can't say if your current brake cables will work, so best to get a complete unit.
SGs are not that common so it might have to be a separate purchase.

7.25s with trac-locs will work with 360autos,on the street,if you don't abuse them too often. Big TCs and neutral drops are out,lol.
 
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