First 'Manche! - '86 Longbed Restoration

[aris_garage_builds]

I just picked up my first Comanche and am very excited to join the forum! Wanted to start a build thread to document the process  It's a 1986 Longbed Custom with the 2.8l V6, Ax5, and 4WD. Lots to be done, but I couldn't be more excited! It's been in CO it's whole life and underneath the truck is immaculate, haven't found any rust on the unibody or floors so far. There is a bit a rust on the corner of the bed (along with lots of dents), so my plan is to weld in new panels in that section and do some body work on the damaged areas. However I'm waiting until the CO snow is over before I start that process as I don't want the clean metal to be exposed to any moisture. So that will likely be a summer project.

 

 

 

 

In the short term, it needs some smaller projects to get it up and running again! First on the list is a new clutch and e-brake. After that, I need to do some work on the interior - overall it's in pretty good shape, but the seats and floor vinyl need replaced. I plan to do some rust prevention and sound deadening while I'm in there. The tailgate latch and both bumpers are damaged, so those need a little TLC.

 

 

As far as long term plans, the bed repair I mentioned will be first on the list. I'm hoping to give it a new coat of paint once the body work has been taken care of (previous owner rattle canned the bed with black paint to slow down the rust spread). My first car was a red wrangler, so selfishly I'd love to own a red jeep again. Once all the rust has been taken care of, I'd like to do a lift and 33's. Nothing too crazy, as I don't plan to wheel this too hard (there's so few of them left I'd hate to chop it up and beat it on the rocks). It'll just be a weekend fun rig to tackle mild trails and do some occasional towing / hauling. In an ideal world I'd like to swap out the rear D35 for something a bit stronger and potentially switch to SOA, although I haven't totally decided yet. I also have a spare 4.0 from an XJ that I'm in the process of rebuilding. If the current 2.8l kicks the bucket, I'd love to swap that in. I hope to update this thread as I slowly chip away at these projects. Excited to meet you all and pick your brains for more MJ knowledge!

 

[aris_garage_builds]

I went to register it in the forum database and found that someone else had already done it! It's (mostly) stock at the moment - the build sheet mentions bucket seats, so someone must have removed those and the center console, because it currently has a bench seat in it and is missing all of the shifter trim. It also has a 21 slot grille and eliminator wheels which I doubt came from the factory haha so someone must have tracked those down. Here's the build sheet I found in the other thread:
 

Build Date 10/31/85

JL62

 

*ZZ    TRIM STYLE ZZ - PLASTIC BUCKET SEAT
-ZZ     
CGX    Head Restraints-Outboard Seating, RR
DDQ    Transmission - 5-Speed Manual
EFB    ENGINE - 2.8L GM 6CYL
GAC    ALL WINDOWS - TINTED GLASS
GEC    Window - Left Side, Front, Sliding
GFD    SLIDING RR WINDOW
GPB    DUAL - O/S MIRR PKG - LOW MOUNT - CHROME
HCC    HEATER W/UPR LEVEL VENTIL - TYPE II
JJA    CIGAR LIGHTER - FRT COMP
LMA    HALOGEN HEADLAMPS
MBJ    Bumper - Front, Black
MDA    FRT LICENSE PLATE ATTACH REQUIRED
NAF    HIGH ALTITUDE EMISS CONTROL PKG
NFA    TANK - 20 GAL FUEL
SBA    POWER STEERING

 

[89 MJ]

Looks like a good project. That 21 slot grille is a hard to find piece. 

[aris_garage_builds]

4 hours ago, 89 MJ said:

Looks like a good project. That 21 slot grille is a hard to find piece. 

Thanks, I'm stoked to have finally found an MJ! I had no idea the 21 slot grille was so rare until I got this truck, I had never seen one in person before.

Big fan of your AMC Eagle build btw! I'd love to work on one someday, living vicariously through your thread in the meantime 

[neohic]

Welcome! Where in Colorado are you located? There’s a few of us sprinkled around the state. 

[89 MJ]

10 hours ago, aris_garage_builds said:

Big fan of your AMC Eagle build btw! I'd love to work on one someday, living vicariously through your thread in the meantime 

Thank you! They make a great companion to MJs. 

[89 MJ]

10 hours ago, aris_garage_builds said:

Thanks, I'm stoked to have finally found an MJ! I had no idea the 21 slot grille was so rare until I got this truck, I had never seen one in person before.

They were 84 and 85 XJ Wagoneer only. 

[aris_garage_builds]

6 hours ago, neohic said:

Welcome! Where in Colorado are you located? There’s a few of us sprinkled around the state. 

 

Thanks! I'm in Boulder  Hoping to cross paths with more MJ owners here once I get the truck up and running again.

[aris_garage_builds]

Mother nature decided to give us a fool's spring over the weekend and temps were briefly in the 60's. So this was my first chance to really crawl under the truck and start on some work. I took some time to take a good look and inspect things while the ground was snow free and then got started prepping to drop the transmission for the clutch replacement.

Upside to having no console trim or carpet is that removing the shifter was a breeze. Just had to remove a few bolts on the inner shift boot and pull it out. Here's some of that vinyl floor material I mentioned that needs replaced. It works in the short term but is super torn up.

Next I removed both driveshafts. There's currently no E-brake in the truck, so I had to lift and lower it a few times to access the different bolts since the only way to keep the shafts from spinning was to put everything in gear and set the rear tires back on the ground. Overall, the hardware was in pretty good shape and fairly easy to remove after soaking in pb blaster for a day or two. The u joints however are in pretty rough shape, so I went ahead and ordered some spicers so I can just replace those while I have the driveshafts out.

Then, I ran into my first roadblock haha. As expected, the exhaust bolts are totally shot. Specifically right where the cat bolts up. I spent the better part of an afternoon with an angle grinder, a mallet, the biggest breaker bar I own, and an ungodly amount of pb blaster. Made some progress, but wasn't able to get them all before the day and good weather ended. So I had to call it quits and prep the truck for the incoming snow. On the bright side, weather should warm up again in the next week or so and I'll be able to jump back in and finish removing the trans.

 

I want to minimize the bed rust spreading during the snow, so I made a poor mans tonneau cover (wood and harbor freight ratchet straps haha). And then threw a waterproof cover over the whole truck. I haven't been able to find any kind of tonneau or bed cover that fits the long bed so far, but I'd like to have a better long term option for dealing with the snow. Haven't decided yet if I'd rather build something custom / low profile, or just keep an eye out for a topper on FB Marketplace. I like the idea of being able to camp out of the topper when this eventually becomes my weekend mountain rig, but I don't have a great option for storing it when it's not on the truck.

 

[aris_garage_builds]

Snow melted, which means back to the transmission removal! I spent another hour or two wrestling those exhaust bolts, but finally got them out. Excited to replace these and hopefully not have to deal with this headache again. I plan to eventually replace the exhaust, but curious to see if it passes CO emissions as-is (according to the maintenance records from the previous owner it passed back in 2019). If I swap a 4.0 in, I'd like to wait to replace the exhaust until that happens. But that's long term plans, short term goal is to get it back on the road 

 

Next, I pulled off the crossmember. These bolts were also super rusty, half of the bolts actually snapped on me. I've never seen that happen before with crossmember bolts. So I guess I'll need to replace those. Add that to the rapidly growing list of repairs haha.

Finally, everything is out of the way! Next I disconnected the clutch line and all of the electronic connections, and unbolted the transmission. Luckily I didn't have the dreaded torx bolts at the top, but they were still a real pain to get to. Apparently I need some even longer extensions. As I dropped it down, the weight of the transfer case caused the transmission to rotate a bit on me, so I had to pull out a floor jack to help stabilize it.

But finally, she's off! Next up, clutch replacement and refreshing the clutch hydraulic system with a new master, line, and slave.

[aris_garage_builds]

When I pulled the transmission I also got my first good look at the transfer case (the tag was super worn and I couldn’t quite make out the numbers when it was bolted up to the truck). I was surprised to find a 207! Seems like these might have been only offered on the 86’s, not super sure. If I end up 4.0 swapping it, I might look for a 231 to swap in as well, as I’ve heard mixed things about the 207. Really curious to see how it drives once the new clutch is in.

[eaglescout526]

13 minutes ago, aris_garage_builds said:

I was surprised to find a 207! Seems like these might have been only offered on the 86’s, not super sure.

84-86 standard 4wd equipment. Can be found behind the 2.5L and 2.8L. This one is the Command-trac case. The NP228/9 is the selec-trac case that can be found behind only the automatics in 84-86. 87 and up saw the change to the 231 and 242 cases. 

 

My 84 XJ has the 207, its pretty standard, nothing beefy or special there. But what I cant help but notice is mine has the CVT style mounting flange for the front diff on my case. Which means yours just has a double cardan joint that bolts in on yours. Wonder which is the better set up.

[aris_garage_builds]

16 hours ago, eaglescout526 said:

84-86 standard 4wd equipment. Can be found behind the 2.5L and 2.8L. This one is the Command-trac case. The NP228/9 is the selec-trac case that can be found behind only the automatics in 84-86. 87 and up saw the change to the 231 and 242 cases. 

 

My 84 XJ has the 207, its pretty standard, nothing beefy or special there. But what I can't help but notice is mine has the CVT style mounting flange for the front diff on my case. Which means yours just has a double cardan joint that bolts in on yours. Wonder which is the better set up.

That's great to know! Really interesting to know about the mounting differences.

[aris_garage_builds]

Clutch removal went super smoothly, with no rusty bolts it was much faster than the rest of the process haha! Waiting to get the flywheel back from being resurfaced, and then it’s in with new components. Here’s the old clutch and pressure plate and the new ones. Overall, the clutch is definitely a low on material but it’s not totally gone. Which supports my theory that the master / slave are the deeper issue.

 

Sure enough, the master cylinder was bone dry, and both it and the slave cylinder looked like they had leaked. Removing them did not go as smoothly as the clutch, those bolts were super sized up. I ended up cutting the old line to get it out since I already have a replacement on hand, and there was no fluid in the line or slave either. Eager to get the new master, slave, and clutch line installed and see if that solves the issue.

 

[aris_garage_builds]

While I was underneath the truck, I found a few other issues that have been added to the repair list. Firstly, I was planning on doing the rear main seal while I’m down here and the seal I ordered is the older style single piece. However, it almost looks like mine has the two piece style seal. There’s a ton of gunk and buildup, and looks like it’s leaked previously so it definitely needs replaced.

 

Second, I found a generous helping of bondo inside the trans tunnel. I’m not sure if this was an attempt at a previous floor rust repair? This is a future me problem I think, I’ll add it to my list of body work that will be tackled this summer.

 

 

Finally, I noticed a leak coming down the firewall towards the passenger front control arm. When I followed it all the way down, it appears to be coolant leaking since the fluid is bright green. Sure enough, I followed the trail up to one of the radiator hoses. Looks like possibly faulty heater control valve. Luckily it looks like a slow leak, but replacing this has been added to my shortlist.

 

 

[aris_garage_builds]

Progress has been a bit slow the past week or so as life has been busy, but I’ve been doing my best to chip away at this project with any spare time I could. First thing’s first, after doing some research I do have the wrong rear main seal part. It appears I have the internal one that requires a little more engine disassembly than I want to throw into the mix right now. I cleaned up the oil pan and monitored the seal for a day or two before moving forward with the clutch… and at the moment it appears to be a very slow and minor leak so not something that concerns me too much at the moment. I’ll keep an eye on it, but I don’t plan to keep the 2.8l long term so perfectly rebuilding it isn’t my number one priority. I’d much rather focus on getting the truck driving again.

 

So with that, I picked up my freshly resurfaced flywheel from the shop and moved on with installing the new clutch and pressure plate. I also installed the new master cylinder, slave cylinder, and clutch line. The new line I ordered only came with 2/3 of the sections needed, so luckily I was able to reuse the last section of my old line that connects with the slave. The new line on its own would have been a bit too short. It was listed as an MJ part, but wondering if it might have actually been for an XJ? Luckily I was careful when removing it and was able to salvage part of the original line.

 

As I mentioned previously, multiple of the crossmember bolts snapped on me during the originally transmission removal. So I spent a bit of time remedying that. I first tried an extractor but that actually snapped as well  So I ended up just drilling and re-tapping each of the bolt holes and picking up some new hardware. Hoping reassembly will go a bit more smoothly.

 

While the transmission and transfer case were out, I gave them a good cleaning. They were covered in grime. This would have been significantly easier if I owned a power washer or any kind of parts cleaner, but I got them as clean as I could scrubbing by hand.

 

 

I also got started on replacing the driveshaft u-joints while I had them out. These have definitely seen better days, so hopefully the new spicers will help give them some new life.

 

 

Then I finally got started putting the transmission back in… and it was just as tedious as expected haha! I spent a few hours wrestling it, but just couldn’t get everything to align for the life of me. I ended up loosening and re-installing the clutch and pressure plate again just to confirm that wasn’t the issue, but still no luck. I could never seem to get it that last half inch, so I assume the output shaft just hasn’t seated with the pilot bearing yet. I finally had to call it quits at the end of the day when some heavy rain rolled in. But as soon as the weather clears I’ll go back for round two and hope I have better luck. Eager to get this transmission back in and finally drive it!

 

 

[eaglescout526]

26 minutes ago, aris_garage_builds said:

The new line on its own would have been a bit too short. It was listed as an MJ part, but wondering if it might have actually been for an XJ?

So from my experience and knowledge, the aftermarket replacement clutch lines cater to the later years with internal slave but will work on the early years so long you have that line. You and every other 86 owner and me have the external slave with a special line that goes up and over the trans to the slave. I actually got incredibly lucky and scored two or three of them as NOS. 

[aris_garage_builds]

10 hours ago, eaglescout526 said:

So from my experience and knowledge, the aftermarket replacement clutch lines cater to the later years with internal slave but will work on the early years so long you have that line. You and every other 86 owner and me have the external slave with a special line that goes up and over the trans to the slave. I actually got incredibly lucky and scored two or three of them as NOS. 

Oh that makes a ton of sense! Glad I was able to reuse that section of line. Thanks for the insight!!

[eaglescout526]

Happy to provide the insight for the early years!