Bob is out of Jupiter, Florida and runs this 1990 truck with 16/35/r15 boggers on 15x14 steel wheels.

Bob also uses this as his daily driver and has put 15000 miles on the gears that I set up for him last year. See this documented install from Feb of 2006 gear install.

That's gotta be tough on the quarter panels.

These are the 16 inch wide boggers that Bob switches to for the week-end mud runs.

Bob may have exceeded the over-all strength of the gears from the last install. This is not a catastraphic failure.... he heard some strange bangs and noises on occasion and during an oil change noticed some chunks of tooth in the pan. Upon removal of the 3rd, chunks were missing from the heel of the tooth only on about 7 teeth.

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CBPL was still tight (carrier bearing pre-load).

Now to remove the case so I can check the PPL (pinion pre-load).

The PPL was non-existent...it was actually slightly 'wobbly'. Excessive pinion bearing wear had occurred.

Looks like some of the mud made it by the seal.

Some black oil was still trapped under the solid collar.

The pinion teeth looked very much 'chromey'... I don't know for sure if that's good or bad for 15,000 miles on them. None of the pinion teeth were chipped or broken in any visual way.

The OTC-4520 puller made quick work of removing the carrier bearings.

I used red Loctite on the last install....the electric impact had to work a little harder to get the 10 bolts off.

I 100% inspected the Detroit SoftLocker and all was good. No missing rectangular teeth.

After talking to Bob about strength and durability, it was determined to use a Motive brand gear in combination with cryogenics. The bearings would be cryo treated also.
In the pic above is Charles (Dr. Freeze), owner of CRYOGENICS INTERNATIONAL... I chose Charles partly because he's only 30 miles away. Also, after talking to him about his process, I realized that he doesn't cut corners and does a pro job. Charles's process takes about 3 full days...this is because he sets the computer controlled chamber to take the parts down to the target temp of about -320F VERY SLOWLY. The same goes for coming back up to room temperature....very slowly. This prevents thermal shock to the parts but also uses more liquid nitrogen.

I dropped off Bob's ring and pinion and bearings to Charles for the deep freeze treatment. I also had numerous other sets of bearings thrown in the mix with a box of razor blades....packaging and all. After I picked up the parts from Crygenics International, I used the dremel tool to carefully mark each piece as some sort of proof that it was actually cryo'd. Small orders like mine costs $6 per pound.
By the way, the box of razors only weighs about 4 ounces so the actual cryo treat was only about $1.50 above the store cost of $14. The blades will now last 300 to 500% longer :)

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The usual steps were done here...filed the ring gear mount surfaces, red loctite, and 75 ft/lb of torque. Notice that the 50 ml red loctite bottle on the left side of the pic is upside down? That's because I'm almost out. A new larger 250 ml bottle of Loctite 277 is heading my way :)

Both carrier bearings are pressed onto the Detroit Soft Locker at the same time.

"C6" means that it was item #6 in the cryo batch.

As seen in the other links, the races are also pressed in.

Using a shim value of .040" on the solid collar gave a very firm 19 in/lb of pinion drag. This is just above the upper limits as specified in the Yukon cheat sheet. Bob needs this extra pre-load for the strains of mud bogging.

Using a pinion shim of .214", the pattern is right on.

Nice coast. I'm glad that both drive and coast favor the toe end of the tooth for competition reasons.

Even the pinion pattern says GREAT!

This ole dog can still learn a trick or 2....James from Binghamton, NY (code name 'JamesD' on the Yotatech.com bulletin board) passed this 'trick' to me for keeping the spring from popping off the rubber lip...

... by packing the thickest grease you have all the way around the spring like this. The spring will now stay put. Thanks James

I banged the seal on....no worries :)

After cranking the carrier bearing spanner wheels to 150 ft/lbs and holding the backlash at 7.5 thou, the bearing cap bolts are then torqued to 75 ft/lb.

Date-coded.

Back to Jupiter.

I get these plastic 10 gallon totes from Walmart....other department stores have similar totes for about $3.50. I place about 4 layers of cardboard on the bottom...

The 3rd gets burrito wrapped.

Some cardboard is then packed around the sides and it's ready to go. This is alot easier than using cardboard boxes as the main container for the trip. Boxes can self-destruct en route.