I found some used gears and a ford posi on ebay, is there any probs with buying used gears? I would really like to do this so I can save some money. Let me know what you guys think.

 

I wouldn't be afraid of the posi unit, but the used gears might not be a good bargin. You might get some gear noise with the used gears unless you know exactly how they was installed initially. IE--pinnion depth & backlash settings. If they can provide you with those exact measurements, then it might be worth the risk IMO.

 

I think they came out of a stock f150, so wouldn't that be stock setting?

 

There is a wide range of settings with OEM gears that are aceptable. Aftermarket gears have the pinnion depth marked on the pinnion gear. If you knew what the original shims were, then that would be a starting point. In other words, it would be trial & error until you got an aceptable gear tooth contact pattern & proper backlash settings. Even then, theres still no guarantee they won't make noise.

 

Offroadmaniac,
Did you get the posi unit? I wondered if we were looking at the same one. I've decided to wait until I can just get a new Eaton LS. I just bought the used ATI from Crash and like yourself, I will need better gearing soon. Looks like it will be a little later this Summer before I can afford the gears, Crash is still working on getting all the parts together for the SC.
Rick

 

Yea, I just bought the used posi and gears. Got them for just under $170 shipped. I also wanted the Eaton posi, but saving about 400 bucks is worth it to me, since money is an issue.
Have fun with the ATI. Are you doing the install yourself? I did mine myself, and it's definitely worth it. I learned a lot.

 

I was thinking of having Crash and Skid do it. I'm fairly competant mechanically, but so far this month I have pulled the A/C compressor, done the brakes,(I hate drum brakes) I'm going to try to put Mad's 255 lph fuel pump in this weekend if our maintenace bay is empty, and still need to put a new clutch in if I can find a reasonable price on a centerforce. Besides, it is a used S/C and Crash does warranty the labor. This way, if there are any problems he will be familiar with the unit. I have been following along with your installation and you definately seem to be having fun with it. Good luck with the gear swap, keep us posted, I'm hoping to follow right behind you.
Rick

 

I was wanting to save some money, so that's why I did mine myself. Plus, I probably wouldn't trust many other ppl other than Crash and Skid. But, since I don't live near them it wasn't an option.

I am so glad I did it myself now though. I really learned a lot. I'm pretty proud for installing a supercharger myself at only 17 yrs old.

I'll let you know what the difference is like with the gears and chip. I'm planning on either getting the gears installed this next week or the week after.