1985 AMC Eagle wagon build

[ericjon262]

lol, this locker install is looking like quite the headache...

whats the control scheme? switch on the dash? something more automatic?

Looking at the design apart like that, I would only want to engage/disengage that from more or less a stopped condition.

The vent connection is loose. I'm not sure whether to try to seal it back up, or to pull it out and tap the hole for 1/8 NPT. I will plumb all of the vents (trans, T-case, front diff, rear axle) to the PCV system so that I don't get water inside those units if I ford a stream.

where are you planning to plumb it? I'd recommend on the atmospheric vent side, not engine vacuum side. if a vacuum were pulled on the cases, it may pull water into the case past the seals that probably aren't rated for a high differential pressure. I'm planning to do something similar with the pig rig, plumb all the vents to a common high point, and maybe to an induction snorkel.

[The Dark Side of Will]

Good point about the vacuum. The shaft seals are meant to retain interior pressure, not the other way around. I'll plumb them to the air cleaner on top of the throttle. Short of a snorkel, that's the highest point on the intake tract. I won't (or don't expect to be) fording water that deep with this vehicle.

Yeah, it's a PITA, but I have it figure out. I'm wondering if Eaton would sell me a new carrier for the 3.73 and up ratios. The Eagle Dana 30's were a mess of interchangeability. Eagle 3.54 gears fit the Eagle housing, but Jeep 3.55's require a different carrier. I didn't think they'd changed the housing for the 2.35 gears, but they may have moved the pinion over to accommodate it being that large. If that's the case, the Jeep 3.73 and up carrier becomes the Eagle 2.73-3.54 carrier, while the Jeep 3.54 and down carrier becomes the Eagle 2.35 carrier. Maybe? There's a whole thread on Eagle's Den trying to figure that out year by year. It's worse because once a diff is removed from a vehicle, there's no way to tell what year it was manufactured... although I haven't seen anyone discussing casting numbers there yet.

I'll just have a switch on the dash to control the e-locker. Actually, it *needs* to turn in order to engage. The coil on the end attracts the ramp ring between the coil and the carrier. That force creates friction between the coil, which is tanged to the bearing cap, and the ramp ring. The ramp ring has ramps so that relative motion between it and the carrier causes it to push the pins that move the locking collar. IOW, there has to be relative motion between the carrier and the coil in order for the unit to engage.

Hopefully the one I get for the D44 rear will just bolt in.

[The Dark Side of Will]

Also been working on the Small Block Chevy into Eagle mounts.

I had to bite the bullet and get some misalignment washers for the snout bracket (part marked R4) to hang vertically despite being bolted to bosses that GM did NOT spot face... that is, the surface is as-cast and therefore unpredictable. Prior to installing the misalignment washers, there was a 0.100" difference between the top and bottom bolt holes in the distance from the snout bracket to the snout drop (marked R5 down by the pinion yoke). Now I can get them parallel and actually make spacers for those locations.

There's also a tang from the snout bracket into the left engine mount assembly (bolted to the top of the diff).
There isn't a lot to bolt things to on this side of a Chevy, so I had to get creative

[ericjon262]

I take it the "ramp ring" is the locking ring pictured here?

A closer look at the locking collar and right side gear

I knew it needed an electrical input to work, I was just curious if you were going to use an automatic set with wheel speed sensors to control it, or a simple switch on the dash. I agree some motion would be necessary for engagement, but I can't see that engaging at an appreciable speed, and if it did, I can't imaging it taking a significant shock load well. Does Eaton list any relative speed limits for engagement? if so, you may be able to set up an electrical interlock to prevent inadvertent operation outside of design limits depending on what yo use for engine management. it would be very doable in megasquirt from what I've seen, and as hacked as 7730's have become, probably there too.

[The Dark Side of Will]

I call that the dog ring or lock ring.

You can see the ramp ring here, as well as one of the tangs that lock the coil to the bearing cap.

I don't see a need to go to any length to have the lock electronically controlled. In fact, engaging the lock automatically when detecting wheel spin would be a recipe for breaking axles. Although with 27" tires, breaking axles is a good bit harder than it is with 33's or larger.

[ericjon262]

Ok, I re-read your dis-assembly post, and now I see it works in a manner slightly differently than I originally though. cool.

[The Dark Side of Will]

It looks like it would wear out in 1000 miles, but OEMs install them, so I guess it works fine.

The carrier turns. The marcel spring holding the lock ring in the unlocked position pushes on the pins which keep the ramp ring where it's shown.
Energizing the coil causes the coil to pull the ramp ring against it. As the carrier continues to turn, FRICTION between the coil and the ramp ring rotates the ramp ring so that it pushes on the pins hard enough to overcome the marcel spring and push the lock ring into the locked position. However, the lock ring does not move far enough to allow the ramp ring to rotate freely. Once the unit is locked, the ramp ring is "stuck" with the coil dragging it while the lock ring against its stops keeps it from going further. Thus whenever it's locked and the vehicle is moving, the coil and ramp ring are dragging across each other while the coil squeezes them together.

I just realized that if you back up, it'll be much more likely to unlock. I wonder if that's a "feature".

[The Dark Side of Will]

Step by step modifying the e-Locker to accept the E-clip for the left stub axle.

Here's the clip in place:



Had to face down the annulus previously shown on the pin block:



And add a spacer ring to the side gear. This required boring the ID of the annular ring on the side gear just a little bit. The gear is forged and thus that internal diameter had some draught to it which prevented a constant diameter ring from being pressed in.



The gear on the stub:



Gear, stub and clip installed into housing:



Next step: Tool access notch in the pin block, slight expansion of the slot in the side of the housing, cutting slots in the spider gear teeth (!) for the clip to slide through.

[The Dark Side of Will]

I finally got OnShape customer support to find me a workaround for a bug I found (that they won't admit is a bug) and was able to model this up.
Because the pin block is very hard, milling this won't work, it'll have to be EDM'd.

[The Dark Side of Will]

So the prototype machinist recommended I have this EDM'd because it's hardened.

The machine shop sup at work said he had a cutter that could do it, but he'd just need some time when the boss isn't around, etc.
7 months later it was still on his desk.
So I snagged it and took it to the EDM place.
Two weeks later, tada.
Ooooooh, shiny!
The surface finish in the cut is REALLY good... but that's what EDM does. Per my model, the minimum distance from the notch to the pin bores is only 0.025 or so... pretty good fixturing to cut that without screwing it up.

[The Dark Side of Will]

Here's the tool notch... can just barely see the "tang" inside the poodle ring.



Here's the edge of the poodle ring, all the way up (stub axle pushed all the way in)



And all the way down (stub axle pulled all the way out)



I was able to use a hook tool--a cotter pin puller previously modified for something else--to reach in through the access slot in the housing and pull the poodle ring out. That was my goal, so... AWESOME!

I then carved a slot through one of the spider gears until I was able to slide the poodle ring through it. That slot turned out a lot bigger than I had been visualizing... so I'm coming to terms with that before I carve up another one next weekend.

[ericjon262]

I wouldn't feel good about a cut like that on a gear, there's no other way to get the clip in?

[The Dark Side of Will]

It's only 1.5 teeth each off two of four pinions, so I don't think it'll be a big deal... As long as I can keep the "back" edge of the tooth to help make sure nothing gets out of place. If only Eaton had built an e-Locker 2 for the D30...

The first pic in my post above is of the tool notch with all the spider gears installed... As you can see, there's no other way to do it

[The Dark Side of Will]

ACKSHULLY... I was sitting on the can this morning--which is where all my good ideas come from anyway--and remembered that older VW stuff (like MkIII and the 02A transmission) uses an expanding taper plug to lock the output flange into the transmission. I'd have to drill, bore, ream & slot the splines on the output flange, but that may be a cleaner alternative than slotting the gears. It would still require some of the lathe mods I did to the pin block, but would not require the tool notch. And I have to make a taper plug. Interdasting.

[The Dark Side of Will]

I ordered some of these to play with: https://www.bmikarts.com/Right-Taper-Nu ... 30375.html



Maybe the MFG can tell me what the taper is... but if not I can measure it. This and a long socket cap screw should make the taper lock idea doable.

[The Dark Side of Will]

The taper is 4°16’15”, which comes out to 4.271 degrees. That's not really close to any of the normal tapers...
It looks like it's designed to be a 4.25° taper

Code: Select all

Nominal     Degrees       Deviation
4°16’15”    4.270833333   0             (what the shop QC guy measured with CMM)
4.25        4.25          0.020833333
0.037/inch  4.23795447    0.032878864   (what my dad and I measured mechanically)
7/8"/ft     4.175967665   0.094865668
4mm/50mm    4.581220085   0.310386752

[The Dark Side of Will]

And add a spacer ring to the side gear. This required boring the ID of the annular ring on the side gear just a little bit. The gear is forged and thus that internal diameter had some draught to it which prevented a constant diameter ring from being pressed in.

Just had another brain storm... I just wasn't on the can this time.

This ring that I had made to act as a seating surface for the poodle ring can be re-purposed to be the bore into which the taper-lock mechanism expands. Interdasting.

ETA: Random neurons continue to fire: The ring could go away completely and be replaced by a puck into which a long cap screw threads. The puck could either be pressed into the gear or be loose but simply captive between the gear and the cross pins.

[The Dark Side of Will]

I've finally cracked the code on the Eagle D30 E-Locker



The magic part is the little puck in the foreground. That is the ONLY thing that has to be made from scratch for this to work. The stub axle has to have its end cut off, be gun-drilled and have a counterbore cut in each end.





The socket cap bolt goes through from the outside of the output flange. Not shown is a Parker sealing washer that goes under the bolt head to keep the gear oil inside the diff. The socket head fits into the aforementioned counterbore in the outside face of the flange.



To install, disassemble the E-Locker to this level--that is, almost all the way.



Drop the puck face down into the factory counterbore in the gear face



Assemble the cross-pins. The pin block is upside down because the side that's down in this photo is the side I have not modified. Having the umodified side facing the puck allows me to accurately measure the clearance remaining between the puck and the pin block. This clearance is 0.022". This means that the output flange, when installed, will be able to slide in/out by 0.022". This is ok because the stock amount it could slide was ~0.040". Spider gears were not included as this is just a demo



Insert the stub axle, then install the bolt and tighten it to 15 ftlbs... Voi-la! The stub axle is retained.

[pmbrunelle]

It's a good solution, also friendly for the DIY project guy.

Had there been any sort of mistake with regards to the endplay of the stub shaft, it could have easily been rectified by modifying the puck.

[Honest Don]

These old eagles are way cool.