Topic: Grinding noises

[jagular7]

This is the result of something that gone wrong. I don't know how it happened. Just got finished crawling some rock infested creek bed and up out of it. Then went to go up Walk in the Park (Clayton, OK Green Acres Park) and started up over a fallen tree. Then bang and grind. Backed off and started again. Thought I broke the locker pin/springs. Couldn't wheel the rest of the weekend.




Total of 6+ ring gear teeth. Locker looks good still.

Winching out of the creek bed.


Repair/fix is a 1995 D30R from a XJ to provide a high pinion setup. Also looking into TNT truss to support the axle tubes and hd lower control arm brackets. Still looking for a reason why it broke teeth off. Stock 4cyl/auto/231 with 4.88s/lunchbox lockers.

[aw12345]

The axle housing flexes quite a bit on a low pinion dana 30, is why I went to a high pinion axle
The pumkin on one of those has twice the material thickness add a truss and never look back

[sharpxmen]

was the pinion riding to far out (not engaged all the way) maybe? I had the exact same thing happening in my D35 - no preload on the pinion bearings and made the pinion walk out (away) from the ring - at least that's what I could tell, that or the bearings went bad (they were bad but I put that as the result of bad preload setting). check to see if there's play there by grabbing on the pinion yoke (i had plenty).

[RT]

holy christ, I thought it was nasty when I melted my spider gears in my d35 

[Bounty Hunter]

Let's see, you're gonna source a housing, gearset, truss and brackets?  Why not install a Waggy d44 and add beef to the ring and pinion, along with ALL the other benefits of a d44?

[aw12345]

Well you are forgetting 4 wheels, different rear axle shafts, the Dana44 still needs gears hangs lower. Still needs brackets for the suspension. So it's a wash, Dana 30 HP housing is roughly a 100 bucks, he can still use his locker, gears are a bit over a 100 bucks, if the old bearings are still good you can reuse them. Then the truss from TNT is about 160 bucks, or you make one for about 20 bucks in steel. My Dana 30 HP with truss and currie JJ's for the top came out to about 300 bucks in parts

[neale_rs]

One tooth looks like it got bent down.  Maybe that tooth had metal fatigue from years of use pressing on the wrong side of the tooth due to the low pinion design.

[Jeffy]

Probably weakened it earlier on then it let go.  It all started with the teeth before the bend.  Looks like there was probably a defect or stressed before hand.  Then the pinion slipped, bent the next tooth and broke the teeth off.

[sharpxmen]

those teeth won't bend on these gears, they are extremely hard. It's an optical illusion due to the helical cut and the broken teeth, look at the picture above that you'll see what i mean.

[Jeffy]

those teeth won't bend on these gears, they are extremely hard. It's an optical illusion due to the helical cut and the broken teeth, look at the picture above that you'll see what i mean.

You're right, it's just how the pic was taken.

[neale_rs]

That's true, it's a visual effect having to do with at what level the tooth broke.

[chrisfranklin]

Just a guess here, but it looks maybe tube flex occurred and was great enough that the pinion gear briefly (for a very small fraction of a second) came away from the ring gear and then rebounded, smashing the pinion gear back in to the teeth of the ring gear and clearing out a few teeth until the shaft/tube straightened out.     Again we're talking the entire thing occurring in a fraction of a second

[Bounty Hunter]

Regardless the d30 4.88 pinion is pretty small, I'm sure that didn't help matters anyway, you'd benefit all the way around by bumping up to a real d44.

[jagular7]

The gears have been in the diff for over 5 yrs. They have over 30k miles on them. I think they just had enough. I didn't hear or feel anything in the rocky creek.

Already have a D30R apart in the garage. Getting 4.88's to match rear axle. Yep, pretty much everything on my TJ D30 will transfer onto the D30R.

I'm looking into trusses, but TNT and Ballistic are all I can find for TJ. Pricing on them seems rediculous....TNT truss is $160, then you have to get their upper mounts with it as you cut your originals off and that adds another $130. Ballistic is similar. Poly Performance has trusses but for the JK application and I may 'copy' that into the D30R truss.

As aw12345 suggested, putting together a truss with my own metal will be way cheaper. Finding all kinds of ideas for trussing from JK axle issues. Toyota straight axles come trussed as well. I'll probably beef up the knuckle as well (ie JK issues).

I also like TNT's design of a coil mount and shock mount. The shock mount becomes a stud off the coil mount. This should provide room to bring the lower control arm out from under the axle to even with the centerline of the axle and farther back off it. This could help with bringing the front axle forward.

[aw12345]

I have some ballistic fab coil mounts for a D30 I will let go cheap also, I used the TNT truss, but made my own mounts and stuck 2" currie jj's in there