My First Jeep - A 71' Commando Learning Experience

Discussion in 'Jeepster Commando and Commando Tech' started by Luke V, Aug 20, 2017.

  1. Aug 22, 2017
    Pack Rat

    Pack Rat Old Timer

    I live in a...
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    Nice. Would love to have one that started out as rusty as that ;).
     
  2. Aug 23, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    So, I guess rusty may be to strong of a word.... How about it has some rust? It's really noticeable when it blows up from the floorboards while driving. That will need to be fixed later, luckily my brother is a body tech and does that sort of stuff for a living. On another note, have I mentioned that I'm an idiot? So I did something stupid...

    upload_2017-8-23_8-43-7.png

    I didn't latch the hood from the sides and assumed the center hood latch worked. It does not, not at all. Hood flipped up going 40 mph down the road. Luckily nothing else was damaged and I was able to pull of the road safely, but I do have one more dent to fix; D'oh!

    Some tailgate rust

    upload_2017-8-23_8-47-9.png
    And a little more... I think the PO added his own taillights too

    upload_2017-8-23_8-48-11.png


    So I went through the dash and I was able to get the Temp Gauge working again by simply purchasing a new intake manifold temperature sensor. The oil pressure sensor was also an easy fix, I just to had to get new connections and wire it back up. The Speedometer as I said before works, but bounces quite a bit and reads high - looks like the little controlling spring is worn out, I don't really want to mess with that and break to so it's good enough for now. I also went through and replaced the bulbs with LEDS - they are bright! I'm thinking of using them for under the dash lighting and I'll replace all the marker lights with them.

    upload_2017-8-23_8-54-57.png

    I need to find another blinker and hazard assembly as the plastic internals are busted and the arm will fall and the blinker will always be on.


    upload_2017-8-23_8-57-37.png

    I came across FN Jeep while doing some research. They are in Colorado Springs and have thousands of old jeep parts, I would love to check that out some day.
     
  3. Aug 23, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    I ran a compression test on all the cylinders today. Here was my procedure:

    1. Brought engine to normal operating temperature
    2. Disconnected fuel line
    3. Disconnected all spark plug wires
    4. Loosened all spark plugs approximately one turn
    5. Zip Tied throttle plates all the way open.
    6. Connected compression gauge
    7. Cranked engine over until gauge started to read and released pressure
    8. Let 5 compression strokes cycle, recorded reading and then relieved pressure
    9. Repeated step 8 to confirm


    Every cylinder was the same, 100 psi, is this low? I read that a 9:1 compression ratio should produce about 139 psi of pressure based on a sea level atmospheric pressure of 14.7 psi. I am at nearly 5,000' in elevation and the pressure is just about 12 psi. So, I was thinking I can apply that pressure ratio to the readings I obtained (If it's a linear correlation). 14.7/12 * 100 psi = which gives me approximately 123 psi. Still low, but maybe acceptable? Please let me know what you guys think.I read some other forums where people were saying they were getting close to 160 psi. I just purchased the gauge so I hope it is accurate. I am thinking of running it on my 302 to see what that reads.


    Maybe my timing chain is really warn or jumped some teeth? I will take a look at that since all of the cylinders are reading low. I guess I can also put oil down the cylinders to see if that will tell me anything
     
    Last edited: Aug 23, 2017
  4. Aug 23, 2017
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    Yes, 100 psi is a bit low. But consistent readings is good. Could be that the rings are worn. When you have a consistently low reading across all cylinders, it's typically worn rings. As the rings get very worn, the reading becomes more variable. You can add some oil (about a teaspoon) to each cylinder and see if that improves your readings. A pump oiler works well for this. Oil on top of the rings will improve the rings sealing. It's difficult to predict the compression readings from first principles. You should be able to do it, but static compression is not the same as dynamic compression, which is affected by cam timing.
     
  5. Aug 25, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    That makes sense since the cylinders are in continuous movement while we are measuring them - good to know. I added about a teaspoon of oil to a couple cylinders and the pressure came up to about 115 psi. Worn piston rings sounds like the culprit among other things. I also went and unplugged spark plugs as the engine was running and it was difficult to hear an idle drop no matter where I pulled them from - probably need a tachometer to see the small changes? I will try and put a video on YouTube.



    * The smoke is from coolant on the exhaust manifold

    Also, here is a video of the small knock I hear that sounds like a lifter possibly...



    ________________________________________________________________________________________________

    So I decided to pull the shell and go Commando...

    The taillight bezels were a pain to get off without breaking them and there was quite a bit of "custom" wiring throughout. Also, more pockets of rust

    upload_2017-8-25_8-10-29.png

    Doggo's helping with the teardown

    upload_2017-8-25_8-8-12.png

    And it's off

    upload_2017-8-25_8-11-15.png

    We then wheeled out the frame and started up the pressure washer
     

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  6. Aug 25, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    Grease everywhere - spent about an hour pressure washing the thing to get some of it off

    upload_2017-8-25_10-22-35.png upload_2017-8-25_10-23-11.png


    I guess the next thing to do is take everything else off the frame. My neighbor has an engine stand I can use and a cherry picker. The frame looks very clean with only some surface rust. I think I will try and get it sand blasted and painted. I'll get the motor on the stand and do some investigating and tear down. I'm trying to figure out the best order in which to go through everything (Engine, axles, transmission and transfer case). I would like disc breaks up front and I've found an article that describes how to do a junkyard conversion - (Early Jeep Disk Brake Conversion - Timeless Tech Drum to Disc - Jp Magazine). I could maybe try that route, or it would be nice to do an axle swap for something beefier with disc breaks and an open knuckle. This will all be a new learning experience and I'm bound to make mistakes, but that's the best way to learn.
     

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  7. Aug 25, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    Maybe an engine rebuild is in both of our futures??
     
  8. Aug 25, 2017
    commanlerwrangdo

    commanlerwrangdo Member

    Cleveland, Ohio
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    Nice score on the 71 and welcome to the forum from Cleveland, Ohio.:beer:

    Every Commando I've picked up had seized/dragging/sluggish wheel cylinder pistons. Ive had decent luck just refurbishing the dragging/sluggish cylinders, right down to re-using the cup seals as long as they had a nice seal edge. Amazing that honed rust can seal brake fluid!

    Rust standards differ greatly across the country - you SW folks would scrap rusty Jeeps from up NE, we have to fix that rust all the time if we every want to cruise these Jeeps!:whistle:
     
  9. Aug 29, 2017
    Nekaf&Jeepsterdude

    Nekaf&Jeepsterdude 1968 Jeepster Commando, 1951 M38a1C

    The Netherlands
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    Yeah, from this side it certainly looks like it. I have to find a good, affordable machine shop which can do the actual milling, grinding and surfacing of the internals... There's one in my village but the mostly work on exotic European stuff like Ferrari's and alikes. I hope they can do me a reasonable deal. I do not have a clue what to expect besides a rebuild kit...
     
  10. Aug 29, 2017
    Nekaf&Jeepsterdude

    Nekaf&Jeepsterdude 1968 Jeepster Commando, 1951 M38a1C

    The Netherlands
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    :shock:I did the exact same thing although I do not have a center hood latch. I did it within 24 hours after I purchased my Jeepster. Almost flipped here when the hood went up....
     
  11. Aug 29, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    On no! I guess it needs to happen once to learn not to do it again. Hopefully the shops there aren't to outrageous. I'm getting ready to tear into mine soonish
     
  12. Aug 29, 2017
    Luke V

    Luke V New Member

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    Haha they certainly do as I am seeing in forums! I will have to open them up and check them out if no disc brakes turn up.
     
    Last edited: Aug 29, 2017
  13. Aug 29, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    Ok, where were we....Oh yeah, cleaning grease and tearing apart

    Not much to report I guess, but the tranny, transfer case and engine are off the frame and separated

    upload_2017-8-29_20-27-53.png

    Still need to get a bore dial gauge to check the cylinders, but I am excited to tear it open! I ordered a valve train organizer to help out as well as a some measuring tools, valve spring compressor and piston ring compressor

    upload_2017-8-29_20-28-34.png

    The inside of the tyranny smelled burnt and had chocolate colored oil(Maybe water from pressure wash getting in?). I want to note that reverse would always grind when shifting, but the inside doesn't look terrible, not that I've ever opened one up though. No metal grindings that I could see, but there was a lot of play in the input shaft



    I did an initial degrease and clean on the tranny

    upload_2017-8-29_20-35-28.png

    And the transfer case is still under way

    upload_2017-8-29_20-36-10.png

    Dirt bike Sprockets work well for holding yolks while wrenching on the pinion nut
     
    Last edited: Aug 29, 2017
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  14. Sep 9, 2017
    Luke V

    Luke V New Member

    Grand Junction, CO
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    OK so we have some issues...

    I've been working on getting everything stripped down and ready for rebuild kits. I have the Dana 20 stripped down and I still need to finish the transmission. But, before I continued with those I decided to turn my attention to the engine and see what kind of shape it's in before I put any money into the tranny and transfer case. I also received my bore gauge in the mail; So here we go.

    To begin, the timing chain was very very loose. I had about 3/4" of play, no surprise, but that and the sprockets will need replaced. I then took the rocker arm assemblies, push rods and lifters out with out trouble and the didn't look abused or anything. I then pulled the cam shaft and it too looked decent without any noticeable flat spots and excessive ware. So far no too bad.

    I kept the heads on and decided to take a look at the bottom half. My brother and I began rotating the engine and heard banging around in the oil pan, oh no. What could it be!

    upload_2017-9-9_8-17-45.png upload_2017-9-9_8-20-36.png

    Two main bearing cap bolts sheared!! Not good...

    And since my bore gauge came in lets take a look a quick look at those bores... We pulled the heads and this is what we found:

    upload_2017-9-9_8-22-20.png upload_2017-9-9_8-24-3.png

    Yikes. If I'm not completely deranged, I believe the bore should be a 3.75", not 3.85".I did this measurement on the other cylinders just to see and the are all at least 3.85" - went a little quick through this process, but I just wanted to repeat my measurements (I also used another caliper and arrived at the same results). So what does it all mean Bazzzle??

    I don't know. I took a look at the casting numbers and haven't come up with a ton. The heads have a casting number of 992326; I found some sites that indicate these heads are from a 64-67' Buick 225.

    The block has a casting number of 1254088 - no luck on this one - need help!

    I then researched the 231 engine and it has a 3.80" bore... Oh and I can wiggle the pistons in the cylinder...

    Is this engine toast!!?? (I'm thinking yes - I could be doing something wildly wrong though..) Help!

    Thanks
     

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  15. Sep 9, 2017
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    There's a 1254083 ... could it be that? That's a 1977 231 (3.8L) RWD Buick passenger car motor. 992326 is a late Kaiser-era Jeep PN, but it's not in my list of casting numbers. 231 pistons are 50-over from the 225 (same bore as the Buick 350), and sometimes used for a 225 rebuiild. A worn 30-over 231 would be close to 100 over (3.85") for a 225. Your typical gray iron block can go 60 over with no issues, so a 231 could go to 3.86" without much issue. Beyond that, I would definitely sonic test. If the core shift is minimal. you should be able to go larger, if pistons are available. However, these engines are not rare, and it may be cheaper to go with a better core.
     
  16. Sep 9, 2017
    Luke V

    Luke V New Member

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    Thanks for the info, good to now it can still be bored over!

    I'm pretty sure it's an 8, here's a pic, I can't find anything on it.

    upload_2017-9-9_10-59-2.png

    Anyway, I will see if I can find oversized pistons and see if this will all be worth it. Since it's not the original engine to begin with (and not rare) maybe an engine swap is in order like you were saying??? My brother's shop has a 2008 Trailblazer with a v6 and transmission for about $650. He will get me details Monday
     
  17. Sep 9, 2017
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    Looks like a 3 to me.

    The 4.3L Chevy V6 is a popular swap for these Jeeps, but the Buick V8 is easier. However, the T-14 is not up to V8 power IMO ... a Buick V8 is a great swap in these Jeepsters with a TH400. The main down-side to a Chevy is the distributor at the back interfering with the firewall, so the engine needs to be moved forward a little or the firewall cut back, as I understand it. The Buick V8 sits on the same mounts, and you only have to cut the core support and move the radiator forward - quite a tidy conversion.
     
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  18. Sep 9, 2017
    Luke V

    Luke V New Member

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    You are totally right it's a 3, I think I had 1 to many beers last night. Looks like I'm in for some swap research. Thanks again
     
  19. Sep 9, 2017
    timgr

    timgr Jeepin' Nerd Sponsor

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  20. Sep 27, 2017
    KeyserSoSay

    KeyserSoSay New Member

    Edgewood New Mexico
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    Hey Luke, I'm just touching base with you here, I'm in a very similar boat with a 72 commando I just purchased (out of Durango/Pagosa area) but my build will be lagging behind yours a bit, and I'll be following you closely. I've got a thread here that I expect you'll see hovering around the top over the next 100 weeks.

    I'm torn right now about attempting a full body off as I don't have an indoor shop to accommodate it and my driveway is so steep, the last time I dropped a roll of electricians tape it rolled down to the neighbors property and I never found it. I've got a spot to work on the truck but real estate is at a premium. How many folks did it take to lift your body and move it around?
     

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