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Goofy question about diff covers

Archdukeferdinand

NAXJA Forum User
Location
Boone, NC
So I happen to have 2 stock d30 covers right now... I've been wanting a thicker cover to stiffen things up a bit. Was thinking of welding one to the other to get me a free thicker diff cover.

I know its cheap, but the other axle is just going to sit in the boneyard so I may as well get some use out of it.

Haven't tried lining it up so I can't be positive there won't be issues that make this not work but I can't see how it would hurt as long as the fill plug, bolt holes and gasket surface remain the same.
 
it'll be like having 2 soda cans protecting your stuff instead of 1 soda can, and I don't think they will nest all that well either. if you can weld, plate it with something thick.
 
It actually was looking like they'd nest okay, won't be sure until I pull the cover off the axle that's currently under my jeep.

As for the tin can thing, these both look to be made of 3/16" or so material, I have trouble believing that if I drilled some holes in the outer cover, plug welded it to the inner one then welded the seam between the 2 rings that the result would not be significantly stiffer than stock and most importantly A) cost me nothing and B) Take me about 20 mins time.

I won't be going to the trouble to buy & cut steel to plate the stock diff cover. I'd be done with this project before I even got the steel in hand and after all was said and done I'd be better off just making a new diff cover out of thicker stock except diff armor is pretty low on my list of priorities. I just saw an opportunity to use a part to some benefit rather than let it sit rusting in the boneyard and wondered if anyone else had tried it.
 
It seems like you've already decided you want to do it. Try it, post results
 
If you're willing to entertain a suggestion, I'd say really only "nest" the bottom half of the second cover over the first. That will still allow you to easily get to the fill plug.

Alternatively, punch out the hole rather larger in the second cover so you can access the fill plug, and seal the gap that results.

You may also have better luck if you cut the flange off of the second cover, and plate just the "bubble" over.

However, I honestly think that using the lower half of the second cover as a guard (or just fabbing something up out of flat stock?) would probably work about best.

JMHO, YMMV. Offer void where prohibited.
 
5-90 said:
If you're willing to entertain a suggestion, I'd say really only "nest" the bottom half of the second cover over the first. That will still allow you to easily get to the fill plug.

Always willing to entertain a suggestion, and they're all solid ones.

I've been told that a stiffer diff cover can help cut down on flex and thus deflection in the gears and that's mainly what I'm going for here. Impact resistance isn't much of a concern, I don't hit the rocks that hard.

I'd been thinking that the more thickness I could add to the cover, the stiffer it would be so I'm kind of loath to start chopping it up. This is more of a strengthener than a guard or skid.

Of course this has all been PBR engineered so I can't support my thinking any further than "more metal STRONGER!" If you think that I'd get the same thing just doubling the bubble and leaving the ring off or using just a lower half I'd be interested in either of those.


As for that $55 cover, I appreciate the legwork but I recently bought my first house, am still paying rent on my old place for another month and the rig has more serious issues than diff covers to keep it on the road as my DD...

I'm broke flatta than piss on a platta for the time being and its about $55 more expensive than my tools at my shop with parts I already have.:cheers:

I'll give this a try when I swap axles and see what happens.
 
Archdukeferdinand said:
I've been told that a stiffer diff cover can help cut down on flex and thus deflection in the gears and that's mainly what I'm going for here.
Your never going to see this with what you are doing!Quit being a CAB and buy a good cover!
 
Yeah, but a built-up cover won't help against flexion much - better off fabing a truss. Or buying something like a RuffStuff cover - which looks to be tougher than the Hinges of Hell.

What you're mainly going to be after is protection against impact - which is why you don't need the whole flange (leaving the flange in place will make it harder to stack the covers from the off anyhow.) If you want impact protection and anti-flexion, make a cover (or just buy one.)

For your needs, stacking covers will probably do for the moment (until next year's tax rebate. You spend a lot of time upside-down on a mortgage, and interest on a home loan is usually deductible.)

To maximise impact protection, leave some flange on the second cover - that allows it to brace against the housing in impact, doubles the bracing it gets (from the original cover,) and you still have the "more metal better" approach. That isn't always true - but it's true enough in this case, and I doubt you've got the wherewithal to engineer a new cover.

If you want to really do the job, use the bottom half of the second cover, then run a section of angle iron bent to follow the contour of the cover, angle "point" outwards, and lay it right about over the ring gear. That gives you an extra bumper, works as a stiffening member, and gives the ring gear a little extra protection as well. I'm assuming you already have fab tools (welder a must, torch a help with bending.) You shouldn't need to heat-treat the thing, since you're going to get more strength from the shape than the material anyhow (see why I mentioned engineering?) Using a half-round section of pipe would be a bit stronger, but it's more work.

Whatever you to, make sure you seal against moisture intrusion between the layers! Make sure it's dry, and fill the area in between with some variety of "blow-foam" fill, and then seal shut (or make sure the area between is dry, and seal with a continuous weld bead - but then you run the risk of warping the cover.) Getting moisture/water in between the layers will end up failing both layers - even if you've painted them (paint just delays the inevitable, in this case.) That doesn't mean you shouldn't paint them as well - but apply some thought once you're done letting the paint dry. A couple of extra bucks will save you much more later.

Ideally, you'd want something like a one-piece cover stamped from something like 1/4" or 3/8" plate, but that's impractical (do you have any idea just how much force you'd need to stamp it to shape? Ouch...)
 
I didn't know a wherewithal was an engineering tool. I must have left mine at home.

Thanks for all the suggestions guys but I think its just going to go ahead as planned.

I'll let everyone know if it folds like a taco or if its somehow weaker than stock, my question was never to compare the stacked covers to an aftermarket or more built stocker, only to the bone stock unit. (Which has been on there all 5 years I've owned it).


5-90, I'd looked at trusses a while back and I decided that I probably wouldn't go to the trouble of running one on the upper side of the tube for various reasons and didn't like the idea of running one under because of losing ground clearance.

But after measuring in the shop the other day, I think I could make something low profile that would end up being higher than the bottom of the LCA mounts... I got to thinking of something like a 3/4 or 1/2 round section of tube running from inner c gusset to inner c gusset, being round it wouldn't hang up on things, and I've got scrap that could probably suffice. Probably not as stiff as box in the planes I'm looking for but I still think it'd do (probably overkill) for my needs. Whaddya think?
 
Archdukeferdinand said:
I didn't know a wherewithal was an engineering tool. I must have left mine at home.

Thanks for all the suggestions guys but I think its just going to go ahead as planned.

I'll let everyone know if it folds like a taco or if its somehow weaker than stock, my question was never to compare the stacked covers to an aftermarket or more built stocker, only to the bone stock unit. (Which has been on there all 5 years I've owned it).


5-90, I'd looked at trusses a while back and I decided that I probably wouldn't go to the trouble of running one on the upper side of the tube for various reasons and didn't like the idea of running one under because of losing ground clearance.

But after measuring in the shop the other day, I think I could make something low profile that would end up being higher than the bottom of the LCA mounts... I got to thinking of something like a 3/4 or 1/2 round section of tube running from inner c gusset to inner c gusset, being round it wouldn't hang up on things, and I've got scrap that could probably suffice. Probably not as stiff as box in the planes I'm looking for but I still think it'd do (probably overkill) for my needs. Whaddya think?

Do the "under-truss," but with only a single layer of metal at the bottom of the punkin'. Once you get past that, you can build it out (kinda like metal fillets) to stiffen the tubes and not lose that much clearance - 1/4" or so?

The "under" truss will also help you against bending upwards (that's the more likely direction, no?) because it's harder to pull steel longer than it is to bend it shorter. You'll have the added benefit of using the steel bracing in tension, which means you can do with less material (less unsprung weight.)

Just make sure you're running one solid piece for the "backbone" of the thing for maximum strength. Use 3/16" or 1/4" thick plate, as wide as you think it needs to be. I'd suggest welding to the tubes for a more rigid attachment (=more bracing,) than using U-bolts - just watch you don't warp the tubes (more of a "running stitch" weld then a solid bead. How much do you know about sewing? I tend to explain welds in those terms...)

A "round" shape is usually stronger than a "square" shape (corners are stress risers - the sharper the corner, the more likely it is to give there. That's why roll cages and important structural shapes are round,) so if you've got something like that, it's not a bad idea to use it. Go ahead! Sounds like you've got the core of a solid idea there.

Oh, and "wherewithal" is one of those general-purpose tools. You should find it in your kit with the hammer, duct tape, and superglue. (But there should also be superglue - true cyanoacrylate ester - in your First Aid kit as well. Comes in handy for those small cuts that bleed all over...)
 
When I had an extra 44 cover laying around I made a clock out of it. Painted it real nice and drilled a hole through the bubble. Got the clock kit from a craft store. The mounting holes even line up well enough for the numbers...
 
5-90 said:
Oh, and "wherewithal" is one of those general-purpose tools. You should find it in your kit with the hammer, duct tape, and superglue. (But there should also be superglue - true cyanoacrylate ester - in your First Aid kit as well. Comes in handy for those small cuts that bleed all over...)

I swear by the cyanoacrilate. Even better than nu-skin! In the same toolkit I do have a wherewithawl, but its for woodworking.


I was thinking of 2x4x3/16" box that I've used to make my bumpers and rockers (and was planning on using to do my over-truss) vs some smaller round tubing that I've got around, should have made clear that wasn't an apples to apples comparison.

But since you mentioned it, I know roll cages are tube on the little stuff we're used to but the ROPS in heavy equipment (I work on snowcats and heavy machinery for a living) are frequently box, and those are meant to face rollovers in 25,000+lb machines. Probably an issue of material cost there though I guess.

I think the undertruss and double-decker-diff cover will add some proper ghetto polish to my turdy, thanks for the suggestions.
 
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