fly boy_1

iTrader: (4)

So I've got a MWC fab9 that suddenly started making a lot of gear noise just after the 500 mile break in period (went from a lil noise here and there to constant over 30 when not coasting), and MWC advised me to pull the pinion out and get some pictures of the wear pattern on the gears and hopefully track down the root cause of the sudden noise. I'm going to be pulling the center section most likely, but any ideas what to look for? I sent these pics to MWC to see what they have to say, but I figured I'd put them up here as well.

S10xGN

iTrader: (11)

The contact pattern on that last pic looks just exactly the brand new, never run Yukon set I'm installing right now. It's only been rolled over by hand a few dozen times. Did you set them up? Was there any carrier bearing preload at all?

fly boy_1

iTrader: (4)

Those are indeed Yukon gears. They have about 500ish miles on them. The mesh was set up by MWC when they built the rear. I'm assuming it was all set up correctly, and there might be some random defect or something. Here are some pics of the ring gear.

fly boy_1

iTrader: (4)

Well, it looks like these gears were/are defective. MWC says the ring gear is too worn, but the depth/lash pattern look correct. Gonna swap in some new gears, will be my first time setting them up so if anybody reading this has some good how to links, they would be much appreciated!

S10xGN

iTrader: (11)

Those gears look like they've had some abrasive material in the lube.

Here's what I used:

http://www.7173mustangs.com/thread-h...-a-ford-9-inch
http://www.7173mustangs.com/thread-h...-9-inch-part-2

The only thing I did differently (which may not apply in your case) is the setting of the clutch preload. I followed the Tom's Differential vids on YouTube instead of measuring, although I ended up with the same shims either way. I also got help from www.hotrodders.com in the trans and diff section...

HTH,

fly boy_1

iTrader: (4)

Thanks for the links, much appreciated. This is the gear oil I used http://www.oreillyauto.com/site/c/de...2367&ppt=C1985

00ZNewb

iTrader: (2)

so mwc is making you foot the bill for the re-setup? That doesnt seem right

fly boy_1

iTrader: (4)

No, they are doing the labor free of charge. Im paying for new gears and shims for re set up. They will send the bad gears in to Yukon to determine if they were defective, and if they were I will get refunded for the gears. It sucks but I cant blame Eric at MWC for any of it, if anything he went out of his way to make it right for me!