Well There's Your Problem

I got the 4WD actuator off and partially disassembled. I wasn’t able to move the plunger, but I was able to hear a piece of something rattling around inside the actuator, which doesn’t bode well for its non-brokenness, and finding a replacement for under $100 is not easy. On the forums a couple guys have just wired the drive selector in place in 2WD for daily use. Maybe this will have to suffice for the present.

Before I got the car, one of its known issues was that the transfer case had leaked most of its fluid. I don’t think the location or cause of the leak was known, but I do believe I may have solved that mystery, and it has something to do with this hole right here. 

The hole itself is somewhat baffling as well, since it’s not threaded to accept a bolt or anything. Once I got the transfer case up on the table, I noticed that a few drops of residual fluid had been dripping out on that side, and that’s how I noticed the hole. In a fix that may qualify for endorsement by the Red Green Show, I found an extra bolt from the transmission rebuild* that fit into the hole, applied generous amounts of RTV (Room Temperature Vulcanizing) sealant around it, and called it good. 

I’ve used this sealant to stop several oil leaks in the past, so I’m confident this should work. I’m calling the transfer case done for now.

The exhaust system is the next beast to subdue. A previous owner ditched the catalytic converter and this involved replacing a good portion of the exhaust system. This was fine, since emissions testing wasn’t required in the Eagle’s native mountain home. Problem is, this car doesn’t have a snowball’s chance of passing Arizona emissions testing (and therefore getting registered) with its current setup. Other problem is, the replacement stuff didn’t fit exactly like the factory pipes, so some amateur welding and other metalwork was in order, where simple screws were originally. Now, that’s all got to be undone and replaced.

I’ve made a couple of cuts to undo most of the exhaust system, and the more I think about it, the more it looks like all the pipes will have to come out and be replaced. The tailpipe is the victim of amateur welding and is more rust than steel at this point. Sections up toward the front are also rusted and I think may have been modified as well.

This is way less of a big deal than the transmission was, though. Once the exhaust system is complete, I can put the transmission and transfer case back in. New U-joints will go on the driveshafts, and as long as the transmission repairs are good, the car should be mobile again. Numerous smaller repairs will be needed after that, but for me, right now is where things are starting to get exciting.

*Don’t worry, it’s not something I forgot to put back in. The new pump came with two new bolts, and the bolt in question is one of the old ones.

"I Want The Truck With The Four-Wheel Drive Train"

So yes, the transfer case. When I took it out of the car, it was black, which I presumed was like how cast iron skillets are black, since the outer case was probably made of cast iron. Turns out it was that color because that’s what you get when you mix burned, leaking transmission fluid with the accumulated layers of dirt from off-road hi-jinks. Its original finish is mostly visible now.

It might seem like I’m complaining a lot about how dirty everything under this car was, but if you could see it in person, you’d be just as sincerely baffled as I am at not only the quantity, but the sheer tenacity of such grime. It takes serious stuff to get down to the actual metal on these parts. For me, it’s as Ron Burgundy would say: I’m not mad – I’m impressed.

Circling back to the transfer case itself… It was stuck in 2WD and I thought there was some internal failure that was responsible for this. The good news is that the internals all seem fine, so I shouldn’t have to take it apart. Once I got the adapter housing off, the vacuum-operated actuator that sits on the outside of the transfer case, and shifts the thing between 2WD and 4WD, wasn’t bolted in place anymore, and I could shift it manually. When I do so, everything seems to operate normally. It’s the plunger in the actuator itself that won’t move.

This guy right here

Why? Anybody’s guess. It should only take a small amount of force to move it, but it’s really stuck in place (this is sounding familiar). I think it can be taken apart at least partially, so hopefully that will be somewhat illuminating.

The End Is Here

What has two thumbs and finished the transmission rebuild?

THIS GUY.

Some of the patina of age is still present, but not in a way that matters, mechanically. Alert readers will also noice the adapter housing attached to the back. I originally took that off with the transfer case because of a stuck bolt... which never exactly came unstuck, so I used the angle grinder from before to cut it off. (Thanks and a tip o' the hat to David for lending it to me. Let me know when you'd like it back, and we'll arrange something.) 5 out of 6 bolts should be good... enough. 

As promised, I put a drain plug in the pan (at the lower right of the picture):

It's ready to go back in the car pretty much as soon as I can MacGruber MacGyver it in there somehow. For now I'll be shifting gears (ha!) to cleaning and fixing the transfer case.

The End Is Near

The end of the transmission rebuild, anyway. As previously discussed, when the transmission went down in a blaze of glory, the torque converter and front pump got like, totally wasted, brah. I found some relatively inexpensive replacements, thanks again to the internet, and ordered them as soon as I could be pretty sure I wouldn’t ruin everything else before I would need them. They came on Wednesday...

...and after breathing a sigh of relief that I’d ordered the right parts after all, I dressed up the pump with the necessary seals and such that came in the rebuild kit, and installed it:

I also test-fitted the converter in it, very carefully since I’m now superstitious that it will get stuck like the old one somehow, probably while my fingers are behind it. All good so far, though.

Stuff still left to do for this phase:

- adjust the tension on the clutch bands

- put the valve body back in

- add a hole for a drain plug in the pan, so the whole thing doesn’t have to be removed for a routine service

- reattach the pan and some bits of hardware on the outside of the case

Just One More Reason To Love Citrus

The rebuild has turned a corner, and now instead of taking things out, I’m putting things back in. One pleasant surprise was that when I took apart the planetary gearset (here’s a video of what it looks like and how it works), it was in great shape. Nothing was broken or really even damaged or worn out at all. The clutches, pump, and torque converter took the hit and spared the actual gears that drive the output shaft. So yay for that.

The gears are back in the case, along with the clutches, bands, and various smaller parts. The clutch bands have to be adjusted just so, and for that I’ve got a torque wrench, so hopefully I can get it exactly right.

You remember that at the start, the transmission looked like it had spent time in the Bog of Eternal Stench. It’s still got some dirty corners on the outside, but it’s come a long way. In fact, most of the work of the rebuild was cleaning, and cleaning, and more cleaning. I’ve been using a solution of this solvent in this bin:

washing off the transmission-to-transfer case adapter housing

...the bin having been generously lent/donated to the project by Lydia, the Right Honourable Executive Controller of Household Storage Containers, Defender of the Faith, Destroyer of Tyranny, Taker of Photos, etc, etc.

The solvent is plant-based rather than petroleum-based, which makes it a little more user-friendly, and makes it a little less likely that I’ll be arrested by the EPA/NSA/Google for dumping the used-up solution on the rocks (elsewhere known as “the lawn”).

Almost everything has been cleaned, including the pan, which has made quite a dramatic transformation from this…

To this:

As soon as the torque converter and pump arrive, it will be time to wrap things up and call it good. I’m glad to have this particular adventure (mostly) behind me. Then we’ll go to the next link in the chain, the transfer case. It’s been sitting quietly underneath the table this whole time, behaving itself and trying to look inconspicuous, but it has at least one significant problem: it won’t switch between 2-wheel and 4-wheel drive.

It’s stuck on 2WD, which is what I’ll be using 99% of the time, since I live in a very flat, low-elevation desert, but it still shouldn’t be stuck, and that may indicate other issues. We shall see.

New Year, New Parts

Before we start, this is the stuff the Eagle's nightmares are made of: http://www.thetruthaboutcars.com/2011/05/junkyard-find-1984-amc-eagle/

So anyway, the scariest part of the rebuild is over. I’m speaking, of course, about the valve body. This is the hunk of metal in the bottom of the transmission that has a bunch of holes and channels milled into it. The holes are home to valves and springs and such (first photo), that together with the channels, direct transmission fluid under high pressure to do its various jobs such as actuating clutch bands and so forth.

one of the many pics I took to document how the various things were supposed to go back in

If it sounds complicated, it is. It’s also extremely exacting. One false move and the whole thing can be ruined. Also, cleanliness is paramount. Seeing as how my workstation is outside, I had to be vigilant about particles of any kind getting into the works while it was all open to the elements. Luckily I was able to do most of it in one day, so the chance of making a serious mistake was reduced.

Here’s the completed valve body, shoehorned into a gallon-size bag, to keep out the dust of the urban desert, as well as any moisture, during the wait to return to its home. We don’t get much dew around here, but you can’t be too careful with this stuff.

The front and rear clutches are also completed. This rather dry but short and informative video shows part of that process. Inside the clutch pack is a stack of alternating friction discs and steel plates. Most of the old friction discs in both clutches were worn almost completely clean of friction material (see old vs. new below).

new one is on the right, obviously

new/old frictions and steels. you can't see it, but the friction disc on the bottom right is actually concave from being warped by heat

this is the inside of the rear clutch, freshly cleaned and reassembled with new rubber seals, friction discs and steel plates

The condition of the clutches would probably have led to erratically-timed and sometimes nonexistent shifts toward the end. Some of the steels were also warped and scorched with rainbow-looking patterns on them. Some really brutal heat was going on in there. I’m considering adding an auxiliary transmission cooler later on, but we’ll see. Whatever else can be said, this transmission gave all it had, and died with its boots on, a faithful soldier till the end. Of course, to paraphrase Gen. MacArthur, old transmissions never die, they just get rebuilt.