F-350 Rear Axle Noise

[SuperDutyDave]

My rear axle has been making noise--John sent me this picture but I cannot figure out why this is important

[fords4life]

Nice one. Definitely time for some new gears.

[SuperDutyDave]

You do not think I can nurse it along for another 1-2 thousand miles??

It developed a knock in the last week, today it was bad enough that you could feel it through the floor. I never exceeded 62mph the whole 200 miles to Holtville. Today, the Automotive Gods were truly smiling on my '02 & I--I was really REALLY lucky

[fords4life]

1-2 thousand...maybe....

Yeah, pretty lucky that thing didn't blow apart and destroy the whole rear end.

[SteveBricks]

I dunno man...if he pulled all the chunks out of it you might get lucky for a while, but I sure wouldn't trust it very far.

That knock you were hearing/feeling was the broken chunks being fed to the gears. That could have easily fractured a few more teeth...and who knows what the pinion looks like.

[2005F250]

That doesn't look good. I'm glad everything worked out well that day.

[sanger]

Is that from those tow trucks taking your truck to impound yard?

Sorry to see the bad news.

[SuperDutyDave]

Just like always--John Wood took good care of my truck. In his words, this may have been due to an assembly problem. John said he frequently sees Ford 10.5" rear axles with 500K miles on them. Mine bit the dust at 186.3K. He felt the cause of the failure was the pinion gear bolt(?) was overtorqued, and this has an adverse effect on the bearing races. My bearing races looked like the surface of the moon--very rough and discolored with sizable pits. John mentioned that it took a long time to clean the metal from the axle housing.

No matter what activity a person does, watching someone who is a master at that activity is amazing. John had the inners and both rear axles out. He assembled it, set the lash, shimmed it, did not like what he saw took it back apart, and then reshimmed it and re-assembled it in like 45minutes. John said we were lucky and using Ford parts helped since aftermarket parts, while less expensive, create problems during the shimming process. He said sometimes it can take hours to do a rear axle.

The oil analysis of the rear axle fluid, over 7 samples, showed iron content in the fluid ranging from 2-6 times the average for Ford rear axles. Universal average for iron in the Ford rear axle is 312ppm while mine averaged 746ppm and was as high as 1959ppm. The most distance between oil changes was 40403 miles. John collected the last oil sample during dis-assembly and it had under 24000 miles on it; Mobil 1 75-140synthetic plus 2 Ford friction modifiers were in the pumpkin at the time of failure.

I have changed the rear end fluid in as little as 11,446 miles but short fluid change intervals just prolonged the inevitable. The rear end was failing at a rate faster than normal from the second I bought the truck with 1000 miles on it in 2002.

If anyone has problems, it is worth the drive and expense to go to John Wood Automotive in Holtville. If you need to drop your truck off--talk to John to him and maybe he is finished with a truck from your area and you can drive a finished truck back. Also, there is an Enterprise Rent-a-car in El Centro, only 7-8miles away from John's shop.

RING_GEAR_2011-12-08 07.33.29.jpg

[2005F250]

The diff's in both my parents trucks went out at 180K but I think they still had the original fluid from 99. They didn't loose any teeth though. If it is possible driving back a finished truck makes things easy. Dave drove my truck back when he took his truck to John's. I'm glad John put me in contact with Dave because my truck would've been there probably another 2 weeks before i got time to pick it up.