Kyron's spool/529 US GEAR Install
(26 low res pics loading)
JUNE 16 2004

Kyron was on a night run up Axle Alley in Florence,
AZ and got himself into a bad spot where the rear
tires were tightly wedged......too much throttle 
in reverse led to a BIG noise from the rear diff.
Probably 1 or 2 teeth shattered right there but 70
miles on a tugstrap back to the house definitely
finished off a few more. 

The plan was to keep the costs down......check
the bearings and re-use if possible...use US 
GEAR brand ring/pinions with a solid collar......
and see if the Yukon spool survived the
70 mile ride. I removed the ring gear and
used the dial indicator to check spool
run-out. There were a couple of cosmetic
"dings" in the spool and there was one 
spot where the run-out was at 2 thou....
so the spool was OK. The 70 mile ride home
on a strap....on the highway....was a 
symphany of BAMS and BANGS with a couple
of actual wheel lock-ups. Glad I wasn't
on that E ticket ride. But the Yukon spool
took it all. 

Scruff marks and dings in the diff.

The large pinion bearing was not re-usable 
so I found an 'ok' set. Here I am knocking
out the old cup.

I wanted to re-use that thick pinion shim 
so I had to press the bearing off.

This is my bearing has 
served me well in recent years. I have 
had to use the grinder on the dish surfaces
for clearancing to prevent damage to 
the bearing cages. 

For what it's worth, the original
pinion was shimmed to 98~99 thou. 

Typical Richmond :) 

Inner pinion bearing part number E 32307JN by Nachi 

Pinion loaded up ready for pinion pre-load 
adjustment. .106 for the pinion depth starter
shim. The solid collar has .048" on top of it. 

The dust shield kinda fell off. Somehow it 
lost it's press fit but that was easily 
fixable. With the pinion nut tight, the
pre-load checked in a little low but 
good enough for the 1st paint. 

The Yukon spool is a nice piece of work. 

Carrier bearing PN used on
the spool.....LM603014 (Timken) 

With the spool in and the carrier bearings cranked
tight and maintaining proper backlash....this is 
the drive side using .106" for the 1st shim. Good. 

Coast side. 

Drive side now .108". I tweaked the pinion
pre-load by removing 2 thou from the solid
collar pack(new value=.046"). That gave me
about 8 in/lb as measured by my TW-1 torque

Coast. I cared even less 
for this contact pattern.... I re-shimmed to .103" side. 

coast....seems to be the best balance for
both drive and coast at this point. 

Engrave the ring with specs...

Don't forget the splashguard....if it has one. 

I put some Ultra-Blue RTV 
on.....helps the seal....seal. 

I used some wet/dry 600 paper
on the flange seal surface. 

The dust/mud guard was tacked in place with the MIG.

Grease the seal lip to prevent dry start-up. 

I was getting ready to do the final step and
put the nut on when I noticed the flange 
splines were a sloppy fit on the pinion. 
A new one is on its way from Marlin 
Crawler now.

4 working days later, Marlin sends this new flange. 

Use of blue Loctite and 200 ft/lbs.
 on the pinion nut.....ready to go.