My first FSJ pickup - questions

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Country Jeep
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My first FSJ pickup - questions

Post by Country Jeep »

Hello all! In an effort to make real the saying of "shaking off the rust," I have bought my first Jeep in over ten years, and it is a thoroughly rusty 1979 Jeep pickup. I'm completely new to the FSJ scene, and mostly new to AMC-era Jeep - I only owned an 85 CJ7 and 88 MJ in my teens back in the 2000s. Am an old fart from JF and am posting on some other forums to get as much insight as I can.

Seller stated it's a J-10 with a 360, 3-speed GM THM400 auto, Quadra-Trac, and Dana 44s. Fair bit of rust. Speedo, temp, and oil pressure gauges work; gas and amp do not. Couple of vacuum lines have rotted. The fuel filler and breather tubes to the gas tank are cracked and leaking. Engine has a problem with overheating. Seller installed a new carburetor and new alternator in the past year, and stated the transmission was rebuilt sometime in the past four. Everything else is a mystery.

I'd like some help figuring out if the specs above are accurate based on photos below, and what would be the most sensible game plan to tackle the issues it does have.

Right now, the engine feels like it runs pretty smooth and is firing all cylinders. Oil pressure ~35 at warm idle, ~70 under throttle; black as tar and needs to be changed. Oil pan looks like it may be seeping. Occasionally has a hard time idling once warm and has an issue with slowly overheating when driving under 30 or over 40; when in that speed range, it'll still climb to about 2/3 to 3/4 the way up the temp gauge. The fan seems to be the correct cupped 7-blade design, but it's missing a shroud, and no idea on if the clutch is doing what it should. Radiator is old slam full of rusty water. No idea what water pump it has or if it has a thermostat.

Transmission shifts into all three gears very smoothly and on point, fluid is clean and looks fresh, but either it or the transfer case is leaking. Drove up to 55 without hesitation, no flaring, and surprisingly the truck drove straight without any wobble.

No clue if 4WD is behaving as it should or not, and unfamiliar with Quadra-Trac or how to properly check.

Rust. From what I understand from the bit of research I've already done, there are some common trouble points on these trucks? Here's what I've found so far:
- The full width of the bed at the front nearest the cab has rotted all the way through the floor and cross-member beneath by about 2" front to back, dangerously close to both frame mount points. The respective frame mounts already seem fairly compromised
- The rear leaf springs seem pretty caked in rust
- There are a couple of points on the frame between the cab / bed and cab / firewall that have the black coating fully peeled away and caked in rust, but ball-point hammer suggests they're not fully rotted? Or am I hard of hearing?
- The usual holes in the floor of the cab near the door hinges and along the sides

Right now, in my head, I figure I need to replace the filler and breather tubes for the gas tank first since they're leaking uncomfortably close to the exhaust, then I need to address the overheating (thinking flush > radiator + hoses + thermostat > water pump) and figure out what can and cannot be done with the rust. Do I have that about right or no? What other things should I be looking at if anything, and what realistically can be done with the rust, provided aesthetics are irrelevant here? Plan is not to restore - I don't have that kind of income nor do I think this is a good candidate - but to use as a hunting truck during the mild winters here in the deep south.

Link to photos here - I'll add any as needed upon request.
'79 J10, 360, THM400, D44, PS/PDB

threepiece
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Re: My first FSJ pickup - questions

Post by threepiece »

Hello and welcome from the north.

I usually recommend a thorough cleaning with new old Jeeps. There certainly are specific areas on the frame and body that are dirt magnets, these are usually where most of the damage will be. If you don’t plan on restoring the body I recommend opening up what rust holes you have to facilitate cleaning and air flow/drying. This will help preserve what structure remains.

A thorough cleaning will allow you to familiarize yourself with the Jeep and help you decide what direction you want to go.

If you do decide to restore I make repair patches for the fender, tailgate and frame for your truck. As far as I know these patches are available nowhere else.
I used to name my FSJ’s after their previous owners, I realized I had too many with five named Rick.

Dang raccoons again!

Rust is a color too.

threepiece
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Re: My first FSJ pickup - questions

Post by threepiece »

I suppose everyone has their opinion on what is restorable. I just looked at several of your pictures, your truck is in FAR better shape than my J20 was before I restored it. I guess this is an example of how available resources can influence value.
I used to name my FSJ’s after their previous owners, I realized I had too many with five named Rick.

Dang raccoons again!

Rust is a color too.
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Country Jeep
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Re: My first FSJ pickup - questions

Post by Country Jeep »

threepiece wrote: Thu May 19, 2022 5:20 am I suppose everyone has their opinion on what is restorable. I just looked at several of your pictures, your truck is in FAR better shape than my J20 was before I restored it. I guess this is an example of how available resources can influence value.
That’s reassuring to hear for sure. I plan to do what I can with the resources I have at least, which boils down to: If I find it’s out of reach for me to do the necessary work to stop any further rust and repair what needs to be repaired, I will sell it on to someone who can, as I know these trucks are becoming increasingly rare as the years roll on. I’ve got it now though and am ready to give it a go. I think the seller got in over his head - found an old For Sale sign copyrighted 2018 under the seat that had the truck listed a few years back for $8500 in Florida, and I got it for $4k. That was cash from a weekend car I sold, so I’m not in a hole at least.

How much do those patches you mentioned run? Any details on how they’re installed?
'79 J10, 360, THM400, D44, PS/PDB
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devildog80
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Re: My first FSJ pickup - questions

Post by devildog80 »

Looks like a nice older truck.....on the curb, and if use will honestly be to hunt during the winter.

That said
Yes on fill hoses, but I honestly would put out the cash and get rid of the left bank exhaust pipe.
Too close to tank, so would crossover and only have right bank tail pipe.

Bed
I would consider cutting metal out, frame back in, and put in wood floor
Suggest 2x10 or 12 treated, figure out to fit best so looks good

Cab
Check gauges, blower motor, switches, blinkers, inspect wiring under dash and under door thresholds for serviceability
Check parking brake for function

Cab floor
Cut out as much rust as you can, and weld in sheet metal for floor boards
Tip - Had a '72 Impala bought in NC many years back, then bought a '74 Caprice for parts, and we cut the roof off the Caprice to make a new trunk deck for the Impala, to replace a non existent one. Rotted out from PO oyster catching

Engine
Change oil, replace any/all vac lines needed, check fuel lines, check wiring for serviceability, check routing of all previous away from heat sources

Radiator
Flush out radiator, block, water pump with clean water. Drop the lower hose, pop thermostat out and stick the hose in to flush. You can take the lower hose and raise it then drop it a few times. This will get water pooled in the block then sudden release from dropping the hose will help get some of the heavy stuff moving out.
Same with radiator. Take cap off and flush using same lower hose action.
When you put it all back together, should not need to do any more with cooling system as it should run cool enough without shroud.

Exterior
Check all lights, bulbs, lenses, wipers, wiper blades for serviceability

Axles
Check all fluid levels, inspect/repair brakes

Get your hunting permit and enjoy :)
'81 CJ5 Base, 258 I6, MC2100, T176 4 spd, 300 TC, D30 Front NT, 3.31, 2-Piece AMC 20 rear NT, 3.31, 4" high arc spring lift
'84 Grand Wagoneer, 401 V8 (.030 over), MC2150 HA Comp, 727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT - WT 3.31, 4" high arc spring lift
Rather be driving, than waiting to be modified
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tgreese
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Re: My first FSJ pickup - questions

Post by tgreese »

That pretty much covers it. New belts, hoses, fluids. Put the old rubber parts somewhere in the truck for spares. The small-diameter fuel hoses are a fire hazard, if old. I would get the best quality fuel hoses and radiator hoses I could fine - at least Gates, their premium grade if available. Gates or Dayco are good for the radiator hoses. Heater hoses are a common failure in older cars - best to replace preemptively. New brakes all around are a good investment - replace everything that's available. Any truck from the northeast or midwest probably needs new brake hard lines. Patch the body however you are happy with it - no holes into the cabin. Solid exhaust. Repack the wheel bearings. The CV joint in the front driveshaft is a liability in these Quadratrac trucks - I would rebuild it routinely. If it comes loose, it will smack a hole in your transmission case. Learn about the Quadratrac and do what's needed to keep it running. It's an old truck, so expect some issues. Parts support for these trucks is nothing like Fords or Chevys; expect to go used if needed.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
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tgreese
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Re: My first FSJ pickup - questions

Post by tgreese »

Raybuck used to sell the hat channel that supports the bed floor in bulk. Look around, it may be available somewhere. Cut out the old, weld in new. Or maybe your local HVAC company can make some for you.

If it drives funny, have the alignment checked at the tire shop, and get the printout from the machine. All they can do without a big up-charge is toe-in and center the steering, but the machine printout will show caster angle. Lift springs will change your caster, and I don't see any caster wedges under the axle. You want ca 5-7 degrees positive caster. This is important to making the truck go straight down the road and the wheel return to center. Very common problem with a lifted vehicle.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Country Jeep
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Re: My first FSJ pickup - questions

Post by Country Jeep »

Thanks tgreese and devildog80 (good to see you over here too ;) )

Going to start with the fuel filler and vent hoses. Are these the right ones for my rig?

https://www.gastankdepot.com/jpfh0012-f ... 0-j20.html

https://www.gastankdepot.com/jpvh0012-f ... 0-j20.html
'79 J10, 360, THM400, D44, PS/PDB
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tgreese
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Re: My first FSJ pickup - questions

Post by tgreese »

Maybe. I would look at the factory parts catalog first. Under $25 on CD-ROM from RockAuto.
https://www.rockauto.com/en/moreinfo.ph ... 35&jsn=382

These hoses are probably from MTS, and MTS shows pictures and some description. Unfortunately they do not pair their hoses with the Jeep factory part number. http://www.mtscompany.com/J-truck.htm You can get the MTS stuff lots of places. Summit Racing will probably be the cheapest, if they have it.

I read "coolant" on the side of one of your hoses, and that's wrong. Coolant hoses will come apart when exposed to gas or oil over a long time. I kinda think you can replace what's there with fuel-grade hose and it will be fine. No need to use fancy molded hoses. RockAuto shows both fuel line and filler in many different diameters. https://www.rockauto.com/en/tools/hoses ... se,1001643 If not available in the length you need, possible you can find it at a marine or big truck parts house in whatever length you want.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Country Jeep
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Re: My first FSJ pickup - questions

Post by Country Jeep »

tgreese wrote: Thu May 19, 2022 1:41 pm Maybe. I would look at the factory parts catalog first. Under $25 on CD-ROM from RockAuto.
https://www.rockauto.com/en/moreinfo.ph ... 35&jsn=382

These hoses are probably from MTS, and MTS shows pictures and some description. Unfortunately they do not pair their hoses with the Jeep factory part number. http://www.mtscompany.com/J-truck.htm You can get the MTS stuff lots of places. Summit Racing will probably be the cheapest, if they have it.

I read "coolant" on the side of one of your hoses, and that's wrong. Coolant hoses will come apart when exposed to gas or oil over a long time. I kinda think you can replace what's there with fuel-grade hose and it will be fine. No need to use fancy molded hoses. RockAuto shows both fuel line and filler in many different diameters. https://www.rockauto.com/en/tools/hoses ... se,1001643 If not available in the length you need, possible you can find it at a marine or big truck parts house in whatever length you want.
Catalog on the way! In the meantime, I’ll see about getting the tank empty and taking off the two hoses, see what diameter they are and if I can source locally.
'79 J10, 360, THM400, D44, PS/PDB

letank
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Re: My first FSJ pickup - questions

Post by letank »

that rear metal brake line, the one hanging down from the frame...above the rear axle is getting really rusty... and getting thin.... if you do any work, any motion is more likely to trigger a twist of the hard line and a crack... been there and replaced it...
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (229 Kmiles... the running test lab)
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Country Jeep
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Re: My first FSJ pickup - questions

Post by Country Jeep »

letank wrote: Thu May 19, 2022 7:06 pm that rear metal brake line, the one hanging down from the frame...above the rear axle is getting really rusty... and getting thin.... if you do any work, any motion is more likely to trigger a twist of the hard line and a crack... been there and replaced it...
Much appreciated, I’ll make that a priority parallel with the fuel hoses. I’ve never messed with brake lines before - anything worth noting with these pickups?
'79 J10, 360, THM400, D44, PS/PDB

threepiece
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Re: My first FSJ pickup - questions

Post by threepiece »

Country Jeep wrote: Thu May 19, 2022 8:32 pm
letank wrote: Thu May 19, 2022 7:06 pm that rear metal brake line, the one hanging down from the frame...above the rear axle is getting really rusty... and getting thin.... if you do any work, any motion is more likely to trigger a twist of the hard line and a crack... been there and replaced it...
Much appreciated, I’ll make that a priority parallel with the fuel hoses. I’ve never messed with brake lines before - anything worth noting with these pickups?
Make certain the lines are secure and not able to jiggle about or rub against other parts.
Blow our the new lines just before making connections.
Be sure any connections are in areas where you can swing a wrench to tighten them.
Check all connections for leaks.
I used to name my FSJ’s after their previous owners, I realized I had too many with five named Rick.

Dang raccoons again!

Rust is a color too.
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Country Jeep
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Re: My first FSJ pickup - questions

Post by Country Jeep »

It's monsoon season where I live, so no good opportunity yet to do the fuel lines in open dry air. I did get a few things done, starting with a clean-up of some of the wiring under the hood and replacing the split and stripped solenoid.

Did an oil change. Oil came out black but still liquid, had a Carquest oil filter. Replaced it with a Wix 51258, 5qt 15W40 Rotella, and 11oz ZDDP. Of course the drain plug was already on its way to stripping, so the second I put any torque to tighten it up, it went loose again. Not leaking for now, but will source another one ASAP.

Also flushed out the radiator and engine block. Surprisingly the drain plug was still serviceable. Sure enough, nothing but rusty sludge came out. Took about a half hour to get it and the block to start flushing out clean water consistently. Filled back up with Prestone 50/50, but unfortunately it's still overheating. Didn't see the hot line this time but I think that's only due to the overcast, wind, and rain going down the road - gauge still slowly climbed up to about 2/3. I'm guessing I should start by burping the system?

Also, I found some old parts and maybe one once-new one underneath a bunch of trash in the bed. One of them is a large steel belt that's caked in fresh rust, and another looks like a vacuum canister still wrapped in plastic. Photos uploaded to the original link and found here if anyone wants to sleuth, not really sure what they are.
'79 J10, 360, THM400, D44, PS/PDB
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tgreese
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Re: My first FSJ pickup - questions

Post by tgreese »

Quadratrac chain. You should read the TSM and the article at Jubilee Jeeps. https://www.jubileejeeps.org/quadratrac/index.htm
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Country Jeep
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Re: My first FSJ pickup - questions

Post by Country Jeep »

tgreese wrote: Sat May 21, 2022 1:44 pm Quadratrac chain. You should read the TSM and the article at Jubilee Jeeps. https://www.jubileejeeps.org/quadratrac/index.htm
Done, very helpful. Mine has low-range, so I will start by draining both transfer case and reduction unit as outlined, inspecting belt tension, then refilling. No clue if the one I found in the bed was once new and meant to be installed, or if it was the old one. If it would be prudent for me to check anything else while there, just gimme a heads up.

I read elsewhere here that front locking hubs are sometimes an indicator of the MileMarker part-time kit. Is this true, or should I be looking elsewhere?
'79 J10, 360, THM400, D44, PS/PDB
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tgreese
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Re: My first FSJ pickup - questions

Post by tgreese »

Hubs on a full-time rig are a bit risky. Some chance you'll damage the transfer case by mistakenly unlocking the hubs or mischief. You can run the full-time case as rear wheel drive using locking hubs (or removing the front drive shaft?) if emergency drive is engaged.

If you have a part-time kit, it's supposed to have ATF in it, and the juice will be red. The Quadratrac juice is 30W ND motor oil with friction modifier, and obviously different. You can also test the friction between the front and rear driveshaft like the manual shows. Part time won't slip; it'll switch between loose or locked if your vacuum motor works.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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Yeller
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Re: My first FSJ pickup - questions

Post by Yeller »

May need to replace the radiator. The one in my truck was clean as a new penny and still over heated. Finally caved And replaced it and cured it.
The bus I ride is so short it is a yellow Smart Car full of squirrels, monkeys and clowns.

1970 J2500 Resto Mod
https://www.fsjnetwork.com/forum/viewt ... 12&t=21395

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https://classicbroncos.com/forums/threa ... st-3411909
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Country Jeep
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Re: My first FSJ pickup - questions

Post by Country Jeep »

Either the vacuum actuator is out (looks similar to what I found in the plastic bag?), or it isn’t getting enough vacuum. The latter may be true either way: Two of the three vacuum lines connected to the Quadra-Trac selector are rotted where they meet the lines outside. So I’ll get some new ones.

One question I have that I tried to answer via Jubilee but think I may be dumb, so please bear with: Regardless of which direction I set the switch, the Emergency Drive light is illuminated on the gauge cluster. Where does it get its indication? I see nothing electrical on the switch itself. Also not exactly sure what behavior I am looking for from the front driveshaft to determine current mode - both driveshafts are still present and connected at this time.
'79 J10, 360, THM400, D44, PS/PDB
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tgreese
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Re: My first FSJ pickup - questions

Post by tgreese »

I've only been around these units, never owned one. I would trace out the circuit on the wiring diagram from the TSM. Typically there is a switch with a ball in the end. With a single contact, it grounds the wire and lights the indicator lamp, or with two contacts, connects power. The ball in the switch rides in or out of a groove in the shift rod.

edriveswitch.png
Read the fine manual - 1979 TSM, 2D-21 Torque Bias Test.
You do not have the required permissions to view the files attached to this post.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 Chryco Jeep Cherokee KL Trailhawk, ECO Green
Blockchain the vote.
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