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Gear guru's...gear pattern check...

freerider15

NAXJA Forum User
Location
FoCo, Crawlorado
Alright, getting the gears in my HP60 set right now. This was the first Pattern I tried. Gears are brand new Yukons, set on a brand new Detroit locker. It looks kinda close, think I may add .002" to the non-ring gear side to increase the backlash slighty...the Specs are:

Backlash is a hair over .005"

Shims:
Non Ring Gear side: .052"
Ring Gear side: .046"
Inner Pinion: .025"
Outer Pinion: .064"
Preload: ~25 in/lb.

And the pics:
img0449cl0.jpg

img0447gp9.jpg

img0453pg7.jpg


:D
 
I have never set a HP 60 before, but the pinion is too deep. I would move the pinion forward .006 and pull anothe pattern.
 
Looks like you need to put some more drag on the carrier to get a more distinct pattern, IMO.

Backlash could stand to be a little looser, spec is 6-10 thousandths. But make sure you check the pattern again as it'll change once you do that.
 
91 Jeep Project said:
That is just disgusting.....

Thanks for the usless post :D

Im going to reset the preload tomorrow as I rechecked it, and its not within spec (too low). Im going to keep the inner pinion shims the same, take .002" off the ring gear side to increase the backlash, and I'll see what that looks like.
 
Increase the backlash. I like to run the larger sets at .008

It looks okay though. I'd run it on a front axle.

If it were a rear end. Being a HP, I'd bring the pinion in .005 to the centerline of the gear just to get it dead nuts on center of the tooth.

ANd to get a damn good pattern. Make sure everything is clean. No cosmoline on the gears, and hold your palm on the ring gear to provide resistance as you run the pattern.
 
Backlash adjusts the pattern heel to toe, pinion depth does face to flank. If anything needs adjusting there it looks like the pinion.. although .005 is also too tight. Biggest problem though is getting a good read. Cut the pattern paint with a little gear oil and try again.
 
Take .003 from the inside pinion shims. That will get the depth right and open up the BL by .001 to .002. I would work the depth, while you are doing preload.
 
JJacobs said:
Backlash adjusts the pattern heel to toe, pinion depth does face to flank. If anything needs adjusting there it looks like the pinion.. although .005 is also too tight. Biggest problem though is getting a good read. Cut the pattern paint with a little gear oil and try again.

Im going to try cutting it with a little less gear oil next time for a better reading. Im going to try and shoot for a backlash of ~.007-.008ish. I'll take a couple thousands off the pinion as well...get that dialed in then deal with the carrier shims :D probably won't be able to get back on it until this coming weekend...so it will be a little bit before I have an update.
 
don't cut it with any gear oil. just a very light coating on 2-3 teeth is all you need. Take the preload shims out during initial setup and use the pinion nut to set preload. just remember that you can overtighten it. if you do, back it off, knock the yoke loose a little then snug it back up.
pinion is way to deep. backlash is fine. but thats kinda a shitty pattern so its hard to tell.
I'm going to bed.
 
Alright...here's another try :D

Specs:

Pinion inner: .025
Pinion outer: .042
RGS: .060
NRGS: .036
Preload: 30 in/lbs.
BL: .005

To me it looks good on heel to toe depthwise. I could get it closer to the valley of the ring gear, but that would decrease my backlash and im at .005 right now, which is .001 away from the lower end of the .004-.009" spectrum...

img0468xg7.jpg

img0470ph9.jpg

img0471fe8.jpg


So...thoughts? :D
 
pinion preload is a little tight for my taste. backlash as well. I like BL to be in the .007-.009 area. That might move the pattern off the toe a scosch...
 
Pinion preload according to BillaVista's write-up on Pirate is 20-40in/lbs, so im right in the middle on that. BL is slighty tight, but i'de rather have it a little tighter than looser. Someone suggested on pirate to add to the inner pinion stack, and the RGS shim stack.
 
what does the mfg of the gear suggest for pinion bearing preload? If its Yukon then they spec 17-30inlb on new bearings for pinion preload. and backlash of .006-.010". RTFB. so I guess your within spec on the pinion preload but tight on the backlash.
Its a little hard to tell by the lathering of marking compound.
as I pointed out. a light coating on 2-3 teeth is all you need and I personally would love to see what I call the residual pattern. its where the yellow gets rubbed off on other ring gear teeth as the pinion comes around a second and third time in contact. the pinion pics up the yellow from where you applied it. this is an idea of what I mean on coating just 2-3 teeth or in this case 4.
127-2788_IMG.JPG

and then the pinion comes back around and does this...
127-2790_IMG.JPG

But here is the real kicker... your trying way to hard for a front axle. the pattern you have is perfect for a HP 4wd front dana 60. its not a high speed axle. its a trail axle. your gonna unlock the hubs if you go onto the street and the axle won't spin at all. then when your in the rocks, even an "ok" pattern is fine because your not spinning at any significant speed to create any significant heat to ruin the gearset. and your never gonna hear it whine.
Its also a myth that erring to tight on backlash will compensate for an off pattern and make up for it in deflection. Its the other way around. but thats a whole nother argument.
without being more anal about the application of the marking compound, I'd say leave it alone. if your happy with it. (read previous comment again).
If I sound like an ass tonight... sorry, its tired and I'm late... I'm still beat from 3 days in Johnson Valley
 
Thanks for the replies Ryan. Yeah I know it will be unlocked unless on the trail, but what can I say...im anal retentive when it comes to things like this :D. They are Yukon gears, and i've always heard/read of people liking the BL around .007-.009" so I can be happy with it at ~.008". Man do I miss wheeling JV...these pics looks familiar by chance :D?

dscn0530fm3.jpg

dscn0509cr8.jpg

dscn0532gj3.jpg


I think that was the first run up sledge for both of us :D
 
that second set of photos looks pretty good also. whats wierd is the lack of significant change with that big of a change in pinion depth.
try taking .005 out of the pinion inners and rechecking the pattern. it looks a bit deep on the drive side. but the coast side is near perfect.

everytime I try and get up sledge, we fall in behind another group that is stuck in the same area. I haven't had a chance to run it again since that day.
 
Well this is what I think I will run as my final pattern...

Backlash is ~.007-.008...

img0499gi9.jpg

img0502ji5.jpg


I know the pattern is slightly towards the heel, but after fawking around with it a bit this seemed to be the best pattern I could get while keeping the backlash within a decent spec.
 
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