I posted this on the transmission forum but haven't gotten a reply can somebody help?

Where does an O-ring go I found a broken O-ring in the case?
Are there any tricks with the install.
What type of fluid should go with the new unit?

 

I have no idea of what the o-ring is for? How large is the o-ring?

As for the lube: DO NOT USE SYNTHETIC! The installiation instruction will indicate what lube to use. 85W140??

 

All right I installed the diff today went for a ride and everthing is tight. No noise under load but when I take my foot off the gas and coast on a gear it howels. My question is this normal for Ford Racing gears and will it go away? Also should I keep driving it?

 

The O-ring probably came from one of the axle ends, it's used to help retain the C-clips during axle assembly at the plant. As far as your howl goes, did you setup a new ring and pinion with the Auburn diff? If so, what did you set your pinion bearing preload at? Also, what was your carrier backlash? Usually, a howl on coast down is a pinion bearing preload concern, either too loose or too tight.

 

OK now I'm really confused I read in another post that the howl on costing is to much backlash. But I measured my backlash and it was at .006". I have no Idea what Pinoin Bearing preload is this is my forst diff install.

I used .035" shim on the Pinoin. I tightened the pinoin nut with and Impact wrench and it took alot to crush the sleeve. Let me know what you think I'd really prefer not to disassemble the whole thing again.

Thanks

 

Unfortunately, a first install without a tutor provides ample room for error. You can scroll through here and find out the basics:
http://www.ring-pinion.com/downloads/yukoninstman.pdf
As for noise:
http://www.ring-pinion.com/content/t...lt.asp?pid=109

 

No, that isn't normal for those gears. No, it isn't likely to go away. It's best to have the ring and pinion correctly setup as soon as possible.

 

.006" is a little loose for backlash....008-.010" is about ideal. Very generally speaking, noise from insufficent or too much backlash will make itself known at all speeds during accel, coastdown or cruise.

What basis did you use for selecting the pinion shim? Again, did you set up a new ring and pinion? Did you use the proper depth gauges, or just pressed the old pinion bearing off, measured (hopefully) those shims and reused the same set? Depending on the specific gearset you got, .035-.045 is okay, but this is best determined with a pinion depth gauge set. When you crushed the crush sleeve down, did you just hit it with an impact gun and called it crushed? An impact gun alone won't generate the necessary umph to pull a new crush sleeve down.

At this point, I agree with Max, take it to someone who's in the know and have them go back through the axle before you cause yourself more heartache. 'Cause if something's wrong and it's whining now, it's only gonna get worse.

 

Yes it is a new rong a pinoin set.

And after reading your comment I'll be taking the truck to someone asap. That's what I get for thinking that I could do this my self.

 

All right I've been out of the country for a couple of weeks. Finaly brought the truck to a good trans shop today. The good news is that I did the adjustment ok. The bad news was that my impact gun didn't have enough power to crush the crush sleeve on the pinion gear. So the pinoin was able to move in and out of the differential that is why is was making noise when I coasted. Problem solved $80 to tighten the pinoin nut. Grand total was $875 for everything. The aubrun rear end really locks up both tires nice

Thanks for the help I hope that my post helps somebody else someday.

 

Cool. I love a happy ending.