Comments on gear pattern please...

[MoparManiac]

Dark pics but BL is way too tight and you're a good bit deep.

 

[jeeperjohn]

Dark pics but BL is way too tight and you're a good bit deep.

Needs better pics but I concur with the backlash being too tight. Shoot for .008 backlash and see what it looks like then.

 

[whitexj98]

Speaking of backlash, The FSM calls for I believe .004-.008". Is it preferable to be towards the .008" and why is that?

 

[MoparManiac]

People have all sorts of theories on that.

Some that race or are hard on their shit want to be close to the .004 or even tighter and claim that as you shockload the diff, the backlash opens up.

Others that cruise or do landspeed or whatever that are spinning them fast claim that you don't want the extra heat (friction) of a tighter gearset at high speeds.

 

[Digger87xj]

Speaking of backlash, The FSM calls for I believe .004-.008". Is it preferable to be towards the .008" and why is that?

The FSM spec is for OEM gears.

Always use the specs for the gear manufacturer.

That said, a tighter B/L can cause the gears to run hotter.

 

[Digger87xj]

I have never seen a slinger setting the depth, always shims under the inner race, and I've torn down every single factory axle I have ever scrapped. Also there is a pinion depth+preload shim package in the parts catalog (8350 0192) and a single slinger part number with no thickness listed.

this.

The HP d30 uses a slinger under the head, usually around .028" and then baffle and shims under the inner race.

 

[blondejoncherokee]

I will agree that BL is tight. had to run to west coast diffs to grab a ARB shim kit for the outer driver side shims . 50$ is a lot for the worlds smallest shim kit. Ya I think BL was around .01 to .02. Ill back it off a bit more, and the pinion was too deep in that one and way too shallow in my next pattern.

 

[RWKHausSupply]

I have never seen a slinger setting the depth, always shims under the inner race, and I've torn down every single factory axle I have ever scrapped. Also there is a pinion depth+preload shim package in the parts catalog (8350 0192) and a single slinger part number with no thickness listed.

That doesnt look like a Dana/Spicer #?

Just for future use, as I feel it is easier to get a assortment of slingers and keep on hand for installs.

Here is the dana expert guide to one D30, first on the list that pulled up.
Item
#3
Then you can select thickness of:

# MM Inch
49634-1 0.97 .038
49634-2 0.99 .039
49634-3 1.02 .040
49634-4 1.04 .041
49634-5 1.07 .042
49634-6 1.09 .043
49634-7 1.12 .044
49634-8 1.14 .045
49634-9 1.17 .046
49634-10 1.19 .047
49634-11 1.22 .048
49634-12 1.24 .049
49634-13 1.27 .050
49634-14 1.30 .051
49634-15 1.32 .052
49634-16 1.35 .053
49634-17 1.37 .054
49634-18 1.40 .055
49634-19 1.42 .056
49634-20 1.45 .057
49634-21 1.47 .058
49634-22 1.50 .059
49634-23 1.52 .060
49634-24 1.55 .061
49634-25 1.57 .062
49634-26 1.60 .063
49634-27 1.63 .064
49634-28 1.65 .065
49634-29 1.68 .066
49634-30 1.70 .067
49634-31 1.73 .068
49634-32 1.75 .069
49634-33 1.78 .070
49634-34 1.80 .071
49634-35 1.83 .072
49634-36 1.85 .073
49634-37 1.88 .074
49634-38 1.91 .075
49634-39 1.93 .076
49634-40 1.96 .077
49634-41 1.98 .078
49634-42 2.01 .079
49634-43 2.03 .080
49634-44 2.06 .081
49634-45 2.08 .082
49634-46 2.11 .083
49634-47 2.13 .084

 

[jeeperjohn]

Speaking of backlash, The FSM calls for I believe .004-.008". Is it preferable to be towards the .008" and why is that?

Just because it is within the recommended range. I feel looser is better than tighter within the acceptable range to prevent excessive heat due to the expansion of the gears when they heat up under a load. Anywhere in the recommended range is acceptable.

 

[jeeperjohn]

Here is the dana expert guide to one D30, first on the list that pulled up.

Great info Robert! Thanks for posting that up.

 

[jeeperjohn]

this.

The HP d30 uses a slinger under the head, usually around .028" and then baffle and shims under the inner race.

I have always used the shims under the bearing race to set depth on an HP D30. There have been a couple which were too tight to use the factory oil dam behind the bearing race which required me to set it up without the oil dam. This could have been due to a thick oil slinger on the pinion.

 

[Digger87xj]

I have always used the shims under the bearing race to set depth on an HP D30. There have been a couple which were too tight to use the factory oil dam behind the bearing race which required me to set it up without the oil dam. This could have been due to a thick oil slinger on the pinion.

yeah.. I've seen them as thick as .032-.033" for aftermarket kits that have them.

Sometimes you can't leave it in there... typically not a problem as they are getting aftermarket covers that have a higher fill hole anyway.

 

[kastein]

Robert, good info. That is a crush sleeve low pinion axle, maybe the LP housings normally use a different thickness slinger as the depth shim while the HP housings use shims under the race? All I know is I've never torn an LP down, I consider them to be worth 11c/lb and send em to the scrapyard minus the shafts/knuckles/bearings/yoke, while I usually at least rip more stuff out of an HP housing and have set up or rebuilt a few plus tearing down all the ones I have ruined before scrapping them, and they all had shims under the race.

The part number I gave was a chrysler/dodge/jeep part number - most times if I post a part number that's what it is, as I have a full set of chryco parts catalogs in my reference materials.

I always replace the race, too... may not be required but it gives me some peace of mind since most XJs have probably never had a fluid change in their 100k+ mile service history and who knows how much they sat and/or had water in them. A few minutes with a brass punch and ten bucks for a new race/oil baffle/shim pack is worth it in my book.