I'm considering swapping my 8.8 rearend for a 9.75. From what I've read the 8.8s just seem kind of problematic and weaker than the larger ones. I just rebuilt mine about 2000 miles ago and upgraded to limited slip. The local junkyard said they wanted $750 for a 9.75 and they would drop it to $550 if I gave them mine. That just seems kind of rididculous. I just spent almost $500 on parts for mine but they'll only give me $200 for it? I understand they're out to make money but still...

Anyway, my question is how much could I expect to get for my rearend if I sold it elsewhere? Is this a worthwhile upgrade? I do go off road quite often and the 9.75 just seems like it may have a little more *****. Thanks for any input.

 

That is undeniably true! How could they possibly be sure about that without spending even more for a pro to tear it down again & inspect it? All they know is that it's a USED axle that you want to unload for some reason. They have to make enough to warrant it, in case it blows up w/in 90 days of THEM re-selling it. I just sold a '96 8.8" w/~60K easy miles for $350. The buyer knew the history of the axle & my reputation, so he had a LOT of faith in it to pay that much. I had to store the axle for over 3 years before it finally sold.The stock axle is good enough to go offroad. Do you TOW or HAUL exceptionally heavy loads? Do you have tires more than 4" taller than stock? Do you do rockcrawling? Those are the only GOOD justifications I can think of for this swap. I have a 9.75" core that I was thinking about putting under my Bronco, but it's just not practical for me yet. Maybe if I could find a GOOD cheap 9.75"...

 

I understand that they would have no way of knowing what kind of shape it's in. The only thing that I have to prove it is new is the boxes and receipts that my parts came with. I don't really do much towing. Really the closest I ever some to towing is pulling somebody out of the mud or ripping a tree stump out of the ground, neither of which I really do more than once a week.

I guess it's not really practical to do right now. The only way I would do it is if I could sell my rearend and get the new one for close to the same price. If I were to do it, though, do my 8.8 axle shafts have the same dimensions/splines as the 9.75? Just in case the new one didn't come with them.

 

AFAIK, nothing from an 8.8" will swap to a 9.75", except maybe the ABS sensor on the diff.

 

Don't forget to have the drive shaft shortened if you swap for the 9.75. Try posting on some of the Mustang sites. They then you have a diff with 31 splines out of a pick up.

JMC