Info needed: 1967 M38A1 Lubrication?

[Les Kovacs]

Thanks Rob....I have ordered a pan gasket as well as the two gaskets (PTO & pan) on the transfer case as they too are weeping. I have also ordered a pinion seal for the rear Dana 44.....any issues that you can think of that may arise taking off the pinion?.....does anything have to be calibrated when putting things back?
Also, is it easy to change the PCV valve gasket? Can I just take off the bolt and the whole housing or will anything fall into the crankcase?

PS....I am assuming that you have spent time in the military....are you retired? Also, with all the knowledge you have with repairs to a M38A1, I am assuming that you have one....and if so, what year/batch?

Thanks......les

[rob love]

The pinion seal can be a bugger to pull. Installation is not a big deal, but clean the bore and a slight coating of RTV before seal installaion. A little more RTV behind the washer of the pinion nut as well, in case oil sneaks thru the shaft. You may have to devise a flange holding tool to get the full torque, although guys have been putting it on with impacts for a lot of years and getting away with it.

Nothing will fall in when you remove the sidepan, although it is a bit of a tight squeeze getting it out and then putting it all back again. Put the gasket on with a little contact cement onto the sidecover, and then leave it alone for a bit before trying to install it.

First vehicle I ever drove was a Jeep in the militia at 16. That was 40 years ago. I have built and owned many over the years, but my current one is a CDN3. The Cdn 3 has a few improvements over the earlier models...the frame re-enforcement and self adjusting brakes are far superior to the earlier stuff.

[Les Kovacs]

Thanks for the pinion seal reply Rob....what part of the frame was reinforced on the CDN3?

The pinion seal info/paragraph will be printed and given to the garage that will be doing the seal & bell crank replacement.

I will be doing the spark plugs next when they arrive...any issues there? Is there a special tool to get the wires off? Will any special tools be necessary to get the plugs out?

Also....if you have had a few jeeps.....where do you get your parts from?

regards...les

[rob love]

Any decent mechanic will already know what to do to change a pinion seal....don't insult the guy.

The only problem you may find with the spark plus is that if the last person over tightened the nuts on the sparkplug, when you go to un-do the wire, the whole spark plug may turn. You then have to undo the wire at the cap, then turn the wire and spark plug together to remove the plug.

There is a special wrench for undoing the nuts on the wires, but it can be done with a regular 3/4 wrench just fine. You will require a 1/2" drive 13/16 deep socket to remove the plugs.

Lots of places for parts, but the key for me has been to hoard, hoard hoard.

Lots of Jeep guys around on both sides of the border, and ebay will usually work out as well. Brian Asbury, in your neck of the woods, is usually competitive. I use John Bizal at Midwestern military in the US, and often QTR parts on ebay have favorable prices.

[rob love]

Originally Posted by Les Kovacs

.what part of the frame was reinforced on the CDN3?

The earlier models are prone to cracking on the frame just above the front spring hangers of the rear springs. I saw more than a few of the CDN2 with these cracks. The CDN3 had plates added to the inside of the frame in this area. I never saw a CDN 3 crack in that area.

Other improvements, besides the larger self actuating (and adjusting) brakes, were the fine spline one piece rear axle shafts, the closed hood hinges, and the solid state turn signals, although the vast majority had those installed by the time the Jeeps left service.

[Les Kovacs]

Hi Rob....thanks for the spark plug change info...priceless!
About the pinion seal...back in 1998 I had a 1996 GMC 1 ton 4x4 diesel pickup....it has a pinion seal leak....I took it to a GMC dealership as it was still on warranty....the mech carefully (I watched) tapped in a new pinion seal via a ball pean hammer....I brought it back 2-3 days later as it was leaking worse.....mech again carefully tapped a new seal into the 14 bolt 1 ton axle.....2-3 days later it leaked again....I then did research which said not to tap in the seal with a hammer.....best to use a pinion seal "J" tool....I took it back to the shop....talked to service manger.....I asked him to purchase a J tool to install 3rd seal.....he raked me over the coals saying that his 25 year plus experienced mech does not need to be told what tool to use...I still pressured him to get his mech a J tool....he did...3 days later the pissed of mech installed the 3rd seal with a J tool....I just sold the 1996 GMC diesel to a local farmer....after 16 years it had over 400,000 kms on that 3rd pinion seal...so much for a experienced front end mech....my research saved myself and the dealership time & money in not having to return again...so I am still weary about any mech touching my vehicles....for over 40 years I wrenched on my own vehicles(aside from free warranty work) in short, I would normally do all the work but recently severe arthritis in my hands as all but stopped the heavy work and I now only do oil, filter changes etc. That being said, I am still waiting for all the front end and tune-up parts I ordered last week.

PS...thanks for CDN 2 info....yup, while looking for M38A1's....I had noticed that many had cracks in that area but I just though that the bumper-etts were hit too many times. The brake adjusts are a great addition....my CDN 2 does come with a direction (electronic) signal stalk and seat belts of which I am told were put on during its last years at Petawawa (early 80's)

Thanks again....les

[rob love]

I wasn't sure what you meant by a "J" tool. A quick google check shows that you are referring to the seal drivers as supplied by Kent Moore. The "J" is merely the letter preceding the part numbers.

Personally, I have a reasonable collection of Kent Moore tools as they relate to the various military vehicles. They are always top notch.

[Les Kovacs]

Hi Rob.....yeah....it was a J tool as supplied by Kent Tools.....basically a tool allowing for even pressure to be applied to the seal while driving it into the differential. Anyhow, my wife and I went for our first long drive of 40 kms. Firstly, the rad fluid now down to about 2 inches above the core stopped puking fluid. As well, the temp gauge finally hit 160F,,,great. I now have another issue. The trip was to a car show....the jeep was popular and kids were getting in and shifting gears etc(ignition off).....at the end of the show, when I went to drive off...the jeep would not move...I had to play with the in/out and low/high shifter before I got it into gear and drove home. So, does the in/out transfer case shifter have to be in IN to have the main transmission shift? Please explain.

Regards,

les

[rob love]

There are two levers on the transfer case. The closest one is for 2 to 4 wheel drive. You pull the lever back for 4 wheel drive.

The second lever has Hi range-Neutral-Low range. In two wheel drive, you can only select Hi range or Neutral on the second lever. Hi is all the way to the back, and neutral is in forward one notch. The vehicle has to be in 4 wheel drive in order to select low range. The interlock prevents the high torque of low range from all going in to one axle....instead it goes into front and rear.

So it sounds like the kids moved the right lever one notch forward.

You are a more generous man than I am. When the parents ask if their little angels can sit in the Jeep, I ask that they not play with all the knobs and switches. I watch as their 3 second attention span wears out once they are in the drivers seat. They then begin to test all levers, switches and cables as to their functions, testing them to their limits. Then comes the steering wheel test, at which time they quickly turn the wheel left right left to it's maximum travel, followed by operating the wiper hand levers to maximum speed. No good comes from it all.....it just helps burn off some of the sugar.

Good to hear your radiator has found it's level.

[Frank v R]

a little advice here , install a remote kill switch ,the last thing you want is some little person starting your jeep only bad things happen after that , as Rob said keep great control over who and how people get in your vehicle, things will get broken or go missing, and if you own a rare MV that is very bad, we had a issue at the first Georgina event with kids standing on the WW 2 jeeps and on the windshields , bottom line is keep people out and off your vehicle , you want them to show the same respect to your vehicle that they show to the shiny Mustang, if one of those little darlings gets hurt who do you think will be in great pain after, and if they start playing on one vehicle soon we need to deal with a free for all,

[rob love]

Indeed, the public treats the MVs entirely different than any other vehicle at a car show. I have had kids climb up the nose of a CMP (while the parents stand there watching), and kids (and disadvantaged cultures, while drunk and high as kites) jump into the vehicles without asking. Like ants at a picnic, they will constantly be searching for a weak spot in the defenses. Opening and slamming hatches on armoured vehicles is fair game, and what kid doesn't want to know what happens when you pull that red handle (AFV extinguisher). If you lock up an armoured vehicle, but have a hatch open 8 feet up, then obviously that is an invitation to climb up the sides. And why can't a family of 5 walk up the trails of a gun so they can get into the back of a deuce and a half.

To that end, when I display the museum vehicles or even my own, it's almost always with rope and stands so there are some boundaries. Even then, should the ropes somehow sag to less than 8 inches from the ground, then obviously that means "come on in".

If there is a level of interactivity with a vehicle, then it is strictly controlled. We will rope off a M113 but have the ramp down for an entrance. We allow the kids to get up into the drivers hatch and hold the back of a 50 cal. But it is controlled like a circus ride.....2 people run the display. One at the back of the vehicle limiting the kids to 4 in the vehicle. They get in, sit their butts onto the troop seats, and slide down until it is their turn. The second person tells them how to climb up without hitting their heads, slaps a helmet onto their head, smile and thumbs up to mommy who is taking the picture, then directed off and out the back of the carrier. There is no chinups or swinging from the hatches, a glass partition separates the kids from the drivers seat, no walking around the roof, no testing to see what this lever does (answer: it drops the other kid already up in the seat back to the floor of the carrier whilst shearing the other kids finger tips off).
We will have 30 kids lined up for that 10 seconds behind the gun, and some come back 5 times to do it again, so the thrill is there, but just with safety.

Your vehicle, your choice. But allowing the little angels, hopped up on sugar and with exhausted parents who are looking for a way to hand them off to someone else, free reign on your vehicle in no way promotes history or respect.

[maple_leaf_eh]

Originally Posted by Frank v R

a little advice here , install a remote kill switch ,the last thing you want is some little person starting your jeep only bad things happen after that , as Rob said keep great control over who and how people get in your vehicle, things will get broken or go missing, and if you own a rare MV that is very bad, we had a issue at the first Georgina event with kids standing on the WW 2 jeeps and on the windshields , bottom line is keep people out and off your vehicle , you want them to show the same respect to your vehicle that they show to the shiny Mustang, if one of those little darlings gets hurt who do you think will be in great pain after, and if they start playing on one vehicle soon we need to deal with a free for all,

YUP!

This weekend the Cold War Collection attended the local country fair.
1) Some youngster swiped the master key to a Pinzgauer. A short run back to the garage returned with a spare. Almost every vehicle has at least one additional power cut-off.
2) Having an overhead sun/rain shelter worked well for crew comfort.
3) We have worked out a couple of crew positions for maximum visibility and to allow visitors (kids, moms, and dads) to get the experience.
4) I wipe oily surfaces often and especially before opening to the public.
5) The V100 has split doors which control foot traffic but let parents see inside and photograph little Johnnie wearing the M1 helmet shell or goggles.
6) I have some J-hook magnets and 550 cord to string across openings as another limiter.
7) Earlier in the year we had a kid spin the starter on the V100 - quite unexpectedly! I ordered him out, but the youth's grandfather is a retired colleague of mine! So I had to quickly investigate and form conclusions. Fortunately grandpa is a retired freefall parachutist and recognized the language I had to use. No, I was being safe by being firm, but yes we could have isolated more circuits for the next time. It is added to the checklist.
8) When there are too many little fingers touching things inside and around the cupola gears, I will set the travel lock. We don't want to use up the collection's insurance coverage in one shot on one claim. For more teachable visitors, the locks can come off.
9) The driver's hole on the CVRT is always out-of-bounds.

Finally, I was very impressed when one local beauty in shorts, tank-top, sandals and purse, stepped off the ground onto the step stool, onto the CVRT's wading skirt shroud, onto the deck, reached in and extracted some obstreperous child from the turret, backed off and only lost the ash off her cigarette on the last step.

[rob love]

Originally Posted by maple_leaf_eh

YUP!


7) Earlier in the year we had a kid spin the starter on the V100 - quite unexpectedly!

I put a M113 out for display with almost dead batteries. Feeling that there could be no issue with the kids managing to start it, I left the batteries connected (I no longer do that).

Later, while walking by the vehicle, I noticed a large puddle of bile next to the vehicle and had trouble figuring out what it was. It was then I realized the little darlings had managed to find the full combination of master switch and bilge pump switch, and had bumped the forward hull out onto the parking lot. Luckily nobody had been standing there. They also had pulled the tiller bars off...luckily the vehicle had not rolled forward.

In the end, I considered it a learning experience. As I mentioned before, the drivers position is separated by a sheet of plexiglass, and just as often as not I stick a mannequin in uniform into the driver's seat to prevent the little explorers from climbing up through the hatch and into the drivers hatch. After all, the glass is just a detour and not an obstacle. Mind you, there is a slot for the ramp release lever, and the little arms reach in as far as they can to explore.

[Les Kovacs]

Hi Rob, Terry & Frank....thanks for your comments as per car/military shows....yup....chalk it up to lack of experience with kids at shows...I have learnt a lesson......however, disaster has struck.

Rob....while taking the jeep out for a drive (30kms) on the way home about 500m from home there was a loud ping and I started to loose coolant. I got home well enough but once parked saw that coolant was puking from the water pump puke hole. I called Brian Asbury about 100kms from Barrie and he has a 3 pulley rebuilt water pump so I will be picking one up along with a new thermostat and gasket. At the same time, I will have the rad flushed to clean the core. Any other things that I should do while having the rad & water pump off?

Question....hypothetically, if a chunk broke off of the water pump vanes ( I did hear a metallic pink before the coolant puke)....is it still safe to drive 2-3 kms to a friends house to have it repaired?...my garage is way too small.

Also...back to the shifters, where do the two 4x4 shifters (in/out & high/low)have to be to be able to drive the jeep in two wheel drive?....at times, with the jeep in first or reverse, the jeep does not move after I let out the clutch and I have to play with the other two shifters to get the jeep to move.

Lastly, I put a finger into the tail pipe and its very black and sooty and from what I understand, this may be due to a rich carb...any possible adjustments that I can make? I have not looked at the plugs yet but the jeeps starts first poke/prod and then runs well until shut down.

Best regards and let me know when I have to start paying repair consulting fees.

les

[rob love]

It's your Jeep, so expose it to as much abuse as you would like. A blown water pump is not a disaster....that's just normal maintenance for a 50 year old vehicle.

I would be very surprised if you could hear a water pump vane break. But if the water pump bearing is shot, perhaps that is where the noise came from? If there a lot of play on the fan?

I would suggest topping up the rad with water and leaving the cap off for the couple mile trip. I have seen too many Jeep blocks crack in the center between the #2 and 3 cylinders because of overheating. Unless the leak is of biblical proportions, you should be OK. Your temp gauge will tell you, however they are slow to report if the coolant level is very low.

Shifters: Normal driving. First lever on the transfer case (2-4wd) is all the way forward....it should just about hit the defroster deflector lever. Second lever (H-N-L) is all the way back. There should be a little data plate nearest you on the batch of data plates showing the shift patterns.

Better rich than lean. A cold engine can cause what you describe, leaving the choke on, or merely setting the mixture screw. With the engine hot and running smooth, turn in the mixture screw until the engine starts to stumble. Do not jam the screw all the way in. Now back it out until the engine reaches it's highest idle.

[Les Kovacs]

Hi Rob....thanks for all the replies to my inquiries. Before I reply to your answers one by one I will say that I met with Brian Asbury....I bought a rebuilt 3 pulley water pump from him this AM as well as several other parts....he had nothing but good things to say about you....I will move on.

1. The old pump came off easily...looks good-no vanes/impeller blades broken and there is no play between the vanes and the pulley....in short, it turns fine with no growl. OK....so what made the loud ping noise (just like a M1 garand clip leaving the breach) before the coolant let go through the puke hole?

2. I did not take it too a shop...after 20 years not wrenching on my vehicles (with the exception of wiper changes, oil-filter changes, diff/tranny fluid changes etc) I got down to it with my wife and everything was off, cleaned and paint prepped to be put back on in 3 hours. I will however bring the rad into a rad shop to be cleaned & flushed as there is a lot of brown-grey sludge in and around the core. Question-when I took off the thermostat housing to replace the thermostat....there was none.....why?...what are the ramifications? and how may it have effected the longevity of the engine?

3. Yup...got "all" the data plates including shift patterns but it does not show shift pattern for normal 2 wheel driving ...so for normal driving the 4x4 in/out shifter should be all the way forward-to the dash-firewall (OUT) and the second shifter (low/neutral/high) should be all the way back-towards the seats (HIGH)....right?
I am asking because I have lots of play in the 4x4 shifters and at times in 1st or reverse the jeep will not move once the clutch is engaged but if I play with the 4x4 shifters it will engage......so, once the jeep is put together, I will try it as you wrote it and see if the main transmission shifter will engage in 1st once the clutch is engaged.

4. Rich or Lean? OK....firstly, the jeeps starts first time every time and runs well without a choke start up.....but it possibly requires a leaner mixture....where is the mixture screw?

I was wondering if you can reply in point form as above.

So....out of all of these inquires, the most intriguing is the loud metallic ping and then the coolant puking fluid even though the old pumps looks and feels good. Any thoughts as the wife is now hesitant in future drives in the jeep.

les

[rob love]

I can't explain the pinging sound....likely a red herring: unrelated to the fault you did find. Heck, it could be a 1/2" wrench you left on the skid plate finally fell onto the road.

The lack of thermostat is not ideal. But it normally leads to condensation in the oil (especially at low temps. I recall seeing what looked almost like a film of whip cream on the dipstick in the winter time). As well the engine will not fully burn it's fuel at lower temps. Perhaps that is why your tailpipe is sooty.

Levers should be like you say. They will rattle around if the little spring clips are not slipped between them and the bracket they mount into. If they are popping out of their gear, then you have some transfer case repairs to do.

The mixture screw is located at the bottom inch of the carb, pointing towards the heater. Look for a screw with a spring between the screw head and the carb body.

Can't help on the wife thing. I just kept trading up until I found one who likes/tolerates my toys. Even now she can complain a little too much on a cruise night.

[Les Kovacs]

Rob....enjoyed your last response about the wife....

My thoughts exactly about the sooty tail pipe....a 160 thermostat will go in as soon as the rad comes back from the flushing its getting.....hopefully that will get rid of the soot and run the engine at proper temps....one of my initial inquiries was why the temp gauge never or rarely went past 140 F.

Both clips are in the 4x4 shifters and they are loose but they have never yet popped out of gear....tried the shifter locations you described and it works. I guess at times I never had them in the proper sequence for 2 wheel drive.

Once I get everything buttoned up & working/running I will adjust the mixture screw as per your response.

Thanks for suggesting Brian Asbury as a possible source of parts in one of your earlier posts....he had parts for the CDN2 that many others did not.

[Les Kovacs]

Finally figured out why jeep would not move at times....4x4 shifters were loose with lots of play and they were easily falling out of their position-a look underneath showed that both anti-rattle springs were not in the right place and they were not even positioned-(pushed onto the shift shaft)-took apart top cover & rubber, exposed shift leavers-took out loosely lying springs and placed them in their proper positions on the shifters-pressed them onto the shift shaft and then made sure they clipped into the notches/keepers on the shifters-done...all tight now and more accurate shifting with positive detents.

Thanks Rob,

[rob love]

Geez Les......I think I may have to start to invoice you for the good (lucky) advice.

[Les Kovacs]

Hi Rob...sure...send your invoice....they are piling up as we speak with so many new parts I can't keep track. So far I have put in a thermostat, had the rad flushed, painted etc...replaced all the fluids, greased all the joints, some hoses, installed a fuel filter before the carb and a second before the fuel pump, tied down the fuel line (it was loose and rattling), fixed the shifter spring clips, replaced the carb to air filter hose, shifter rubber and on and on....in the next week I will replace the spark plugs, points/condenser (will require tips from you if possible) exhaust tip, bell crank repair kit, tie rods....so far this jeep feels like a jet fighter of the 60-70's....for every drive hour, it requires 30 hours of service.

Regards,

les

[Les Kovacs]

Hi Rob...

Saturday I put the newly flushed rad in and installed a 160 degree thermostat (remember it did not have any on taking off thermostat housing).

So, here is what happened on start up......the jeep cranked but would not start....usually it starts first crank....I panicked. Did not know why it would not start. Then, I traced back to what I did before the rad flush/thermostat install.....I installed a second fuel filter on the line underneath the rad....first one was in between the carb and sediment bowl....so, I took off the filter near the carb and left the new fuel filter before the fuel pump.....jeep started first crank!

Question #1.....did the two fuel filters make it hard for the fuel pump to pump fuel to carb or what?

Secondly, once the jeep started, I had my wife sit in the jeep watching the temp gauge....I was watching the open rad to see if coolant level dropped on thermostat opening. (Remember initially on checking the thermostat- there was none on taking the housing off-with no thermostat in the jeep temp gauge never went past 140 F) so now, with an actual 160 F thermostat installed, after about 20 minutes of idling (had to recharge batteries) the temp gauge very slowly went to 180 F-but never moved past 180 F parked in my garage but the coolant in the rad-at the rad cap opening never went beyond 155 F (measured by a new rad temp gauge)-never triggering the opening of the 160 F thermostat....Question...is this normal?

Thanks in advance...

les

[rob love]

1: It should not have. The first filter is on the suction side so does not effect the output pressure. And it does not take 7 psi to flow through the filter. Most likely your system was just re-priming itself or there was some dirt in the checkvalves. A person only blows at about 3 or 4 psi...if you can blow thru the filter, the the fuel pump should be able to.

160 is actually the closing temp of a thermostat rather than the opening temp. Opening temp can be 180 or even higher. So likely that is the temp that the coolant opened, or it has not even opened yet, and so is maintaining that temp with no work being performed. If the thermostat is still closed, then it is just the flow from the bypass hose (maybe a 7/16 hole) that is allowing some level of flow.

Drive it and you should see the temp come down to the 160.

[Les Kovacs]

Hi Rob.....thanks for the quick response....wow what a learning experience!

OK....so here is what happened after an actual 25 min drive at about +27 C and moderate humidity....the temp gauge slowly went to about 185 degrees (temp lingered at around 165 for longest time)and stayed there through the whole drive....after garaging the jeep....I checked the upper rad hose...no pressure so I opened up the rad cap and put in a temp gauge....rad coolant read +155 F....Question....is +185 F normal for average summer drive and why was the actual coolant at +155 F?.....also, why did the new thermostat not open?.....is temp gauge reading dubious?

PS...Temp gauge does not fog up any more since putting in a thermostat.

PS...rad cap is dubious as it is old and I had to put in a rubber gasket that was made out of bike tire inner tube. I have no clue what the PSI rating is!

I am ordering two new rad caps....Kaiser Willys shows that a 7 lb cap is required for the M38A1 but the 1967 CDN military manual states that a 4 lb cap is required.

What's the correct rad cap for this jeep?

Thanks.....les

[rob love]

185 is not normal. It doesn't hurt mind you, but it is not normal.

Any chance the problem is in your gauge or sending unit itself? Perhaps you do not have a problem with the actual coolant.

You could try and pull the sending unit, and replace it with one of those cheapy mechanical gauges from Cdn tire or princess auto and see what reading you get.

Otherwise, you have a circulation problem. One possibility is your antifreeze is over-strength (should be 60/40 mix). You already changed your water pump, so that isn't the problem. And the pressure of the cooling system is to merely raise the boiling point, and does not really effect cooling and flow. But if the gauge is at fault, perhaps that is why the last owner removed the thermostat as an attempt to repair a perceived "overheating" condition.

[Les Kovacs]

Thanks for the prompt response....can you please send me a picture of the temp gauge sending unit?...not sure where it is or what it looks like.....is it still available?

So, I can either use a 4 lb or 7 lb rad cap?

Can you also review the procedure to adjust the fuel mixture (new small additional tail pipe somewhat sooty after only 20 min drive)....what temp does the running jeep have to be...cold or operating temp.....

Thanks!

[rob love]

Temp sending unit is on the back right of the head.

I'll have to look the cap up at work today. Fours and sevens are the numbers most often mixed up by dyslexics, so you never trust either.

To adjust the fuel mixture, you have to have the engine idling at operating temperature. You turn the screw in until the engine starts to stumble (usually less than one turn left), then turn the srew slowly back out until you reach the highest RPM. If the engine does not stumble while being turned in, then you have a carb problem. DO NOT jam the screw with force all the way in, as you will damage the seat of the needle and ruin it. In the end the screw should be out about 1-1/2 turns. Ideally, it is set with an exhaust analyzer so you get the mixture right, but those are getting hard to find these days, since every new vehicle has that built in to the emissions systems.

[Les Kovacs]

Thanks for temp sending unit info....I will change out with gauge soon.

I just picked up a new 4 lb rad cap from Bay Auto here in Barrie. CDN2 manual states a 4 lb cap.....Kaiser Willy,s only sells a 7 lb cap.

Thanks for carb mixture info....I will adjust soon.

Took the jeep out again today.....+24C/sunny and humid (solar eclipse here in Barrie was a bust....not much change in lighting.) After 15 min driving-temp gauge showed a tick over 180 F....never moved after getting there. On my return home I immediately opened the hood, felt the upper rad hose (no pressure) so I pulled new rad cap and measured coolant temp....as yesterday at 155-160 F.....not sure how to interpret info....bad gauge?....sending unit? or both?

Please comment.

PS...for some reason your picture did not come through?

les

[rob love]

That's funny, I see the photo just fine. Google M-series temperature sending unit and lots of photos of it will come up.

I am sure there is a proper range of ohms that could be compared at various temps for both the gauge and the sending unit, but I can't tell you what they are. In the army, parts were cheap. We would just change whatever half was easiest, and if that didn't work, we would change the other part. A word of caution when working on the panel. It MUST be grounded before you turn on the ignition switch if you have it off the dash, or you will almost instantaneously burn out any or all of the gauges (oil, fuel or temp). Other vehicles like the M151 actually had a ground wire from the body to the dash,the M38a1 did not. The gauge case must be grounded. Too often, guys would test the gauges by putting power to the smooth connector, and ground to the ribbed connector. The needle might move back and forth, but the damage will be done.

[Les Kovacs]

Nope....I do not see any pics....all I see is a small black box in the lower left corner with an X in it. However, I will google it.

Wow...thanks for the word of caution.....can you walk through the changing of any gauge (eg-temp) starting at taking off the panel and grounding....not sure when to ground....the actual changing of the gauge and sending unit sounds and look easy.

Also....I noticed that there is a hex threaded screw on top and at the back of the generator....is this for lubing? I thought that these units are lubed for life?

Again....thanks for the caution....I would have no doubt shorted out all the working gauges and sending units not even knowing what the cause was.

les