M35A3 Owners unite

[glcaines]

Just keep looking, one will show up cheap.

Ditto. If you get in a hurry you will make a financial mistake. If I see one cheap, I'll send you a PM.

 

[rossbart]

Evening Gentlemen,

I just picked up my first M35A3 from Ft. Hood, TX yesterday. Hopefully there is a pic attached. It seems to be a good truck. 3,100 miles and it fired on the first pop. Engine, brakes, transmission, drivetrain, tires all seem to be okay. The fronts were flat when we got there and the CTIS did "seem" to work as it was able to air the tires up to the pressure that you see (after we put 10 psi in them). Anyway, I have two questions / problems:

1) My main immediate head-scratcher is that the lights don't work. My voltage guage is spot on in the green. The blackout lighs DO work, the dash lights DO work, the turn signals/hazards DO work and the backup lights DO work. BUT, none of the headlights, markers or brake lights work. I have been searching through both A2 and A3 troubleshooting in the TM's but aren't finding anything. I'm assuming that by these symptoms that there is a relay, fuse or fuseable link somewhere that controls the main light system (that is seperate from the BO and turn signal circuits) but can't find anything that confirms that or tells me where, if so. I do note that the dimmer switch on the floor seems a bit tight but I wouldn't think that this would affect the taillights / brake lights in any way?

2) When we got it started and the air pressure built up we turned on the CTIS hoping it would air up the two (nearly) flat front tires. It did seem to work and showed a percentage in the bottom right corner. However, even at fast idle (1500 rpms) it could not get any higher than about 14%. Not exactly sure what that even means. Ultimately it showed FLAT? in the upper right and what you see in the picture is as aired up as it could get the tires. I did hear leaking air coming from the back of one of the rear tires and it, indeed, was blowing a great volume of air. Ultimately we just turned the CTIS off and hoped that the tires would hold the air they had, loaded the truck and came home.

Later we stopped at a truck stop on the way home and aired the tires up and here about 30 hours later they are still holding air. So, I'm optimistic that the fill grommets and wheel O-rings are sound.

Here's my question on this point for you A3 guru's: Was the air escaping behing that back tire indicative of a blown axle oil seal or normal (or something else)? I'm theorizing that the CTIS was just losing so much volume of air there that it could get any more pressure to air up the front line???

Your help is greatly appreciated and i'm glad to be in the A3 owners club now.

Ross

 

[jaymcb]

you might have a CTIS leak. They only give the flat warning when they cannot maintain pressure in a tire.

and I'm jealous you can read your display!

 

[mktopside]

you might have a CTIS leak. They only give the flat warning when they cannot maintain pressure in a tire.

and I'm jealous you can read your display!

Not always. Sometimes if it's too cold the whole system goes tarded and will display flat. Either way, I think jay is right, the line to that wheel is probably disconnected from the fitting. Turn it in, listen for leak....go find leak!

Congrats on the new truck!

 

[jaymcb]

sheesh, in my green envy, I forgot to say congrats on the new wheels

 

[CanonNinja]

hmmmm... had my first transmission issue today....


long post warning...




Driving around today, I noticed as the truck shifted from 1-2, i heard a loud "noise," dont know how to describe it, but it was like a pop or something i thought was in the suspension. Nothing wrong, no smells, no warning lights, cool.... 15min later, I notice the truck lagging from 3-4, and the 3-4 shift was occasionally making a metallic noise. The lag and noise were intermittent on the 3-4 shift, so eh, its cold, truck hasnt been ran this much in a while.


Fast forward to later this evening, after abotu 30min of drive time after the noise, I park it, and notice the front axle is pretty soaked..... sh!T.... from what I could see in the dark lit up by my headlights, was a wet transmission filter, still tight, but wet, couldnt see much above it, but the frame looked dry.


Before I get a chance to go back and look in daylight tomorrow, what do you guys think? Blown seal on the filter? Blown/loose line coming from the cooler?

 

[mktopside]

No idea. If you were losing fluid from the filter (or a blown line) all bets are off as far as what is damaged......or nothing at all. Find the leak, fix it, fill it up, and see who's it runs. Not much else you can do or diagnose until that is fixed.

 

[CanonNinja]

well scratch that.... looks like I had an idiot attack... the oil filter on the front of the passenger side, just behind the radiator is the filter covered in ATF... looks like I answered my own question



eta: well ****, i guess i was right.... checked the TM again. for some reason I was thinking the transmission had a filter on the housing itself. Nope, it is the frame mounted ATF filter

 

[CanonNinja]

No idea. If you were losing fluid from the filter (or a blown line) all bets are off as far as what is damaged......or nothing at all. Find the leak, fix it, fill it up, and see who's it runs. Not much else you can do or diagnose until that is fixed.

i didnt check the fluid level, pitch black, and my flashlight in the truck has grown legs and walked off. I'll have to go back tomorrow morning and figure out what I broke

 

[rossbart]

Not always. Sometimes if it's too cold the whole system goes tarded and will display flat. Either way, I think jay is right, the line to that wheel is probably disconnected from the fitting. Turn it in, listen for leak....go find leak!

Congrats on the new truck!

Thanks for the feedback. I'll look at the air fittings on that tire & see what I find. For now, I'm just leaving the system off and the tires are staying aired up fine.

Do you have any idea about the headlights / marker lamps / brake lights? I definitely have the switch in the right position and the turn signals, BO lights and dash lights work fine. Have any idea what would make all of the headlings, markers and brake lights be inoperative? I'm scowering TM's but no help yet. I'm wondering if there is a fuse or relay somewhere that controls all this OR maybe its a faulty switch?

Ross

Ross

 

[BadMastard]

Hey Ross, did you try turning on the headlights/driving lights, and seeing if the dash lights worked too? If they didn't, I'd bet you have a dead switch. If they did, I'd start thinking you have a wire disconnected near the switch. My money is on the switch.

As far as the CTIS goes, if you hear air leaking from the middle of the truck, that's probably CTIS. May sound odd. If you hear air leaking from the back, could be loose or missing CTIS connector. If you narrow it down to one tire or side, and can't see it, then it's probably on the hub connection, and you'll have to take the tire off to correct. Your tires should hold pressure without the CTIS barring another type of leak.

Congrats! Love ours, works like a champ.

 

[KsM715]

...... The fronts were flat when we got there and the CTIS did "seem" to work as it was able to air the tires up to the pressure that you see (after we put 10 psi in them).

I know you A3 guys hate seeing me post in your threads, but........


Please swap those front tires to the rear. There have been several tires come apart front sitting flat for long periods of time or being moved around the yard on flat tires. It appears that the tires come apart from the inside and is not something that can be seen from just a visiual inspection. Would rather see you have a blow out on a rear rather than a front steer tire.

 

[BadMastard]

oh, good point! you do want to swap those tires. If your spare is like mine though, you'll want to air it up and test it before you use it. My spare tire was unused, but the rim had a bad oring in it. Also, they probably cranked your wheel nuts on as tight as they could, or they will be majorly loose. Didn't seem to be an in between.

 

[glcaines]

Ditto on switching out the front tires to the rear. I had a blow out during my A3 recovery. Fortunately, it was on the rear, but it was still bad. I would highly recommend changing out the motor oil in the Allison for Dexron III. Use the drain and fill technique and change out both internal and external filters. The A3 external transmission filters have a habit of coming loose and leaking fluid. Don't get tempted to overtighten it, just check it often.

 

[rossbart]

Excellent information guys. Thanks alot. In response about the headlights, "yes", the dash lights DO work with the switch in 'Service Drive' position - but that's all (no headlights, no markers, no brake lights. But, the odd thing is that the hazards and turn signals DO work? I have three other (A2) dueces and a couple M817's so I can swap the switches out of one that is working fine and see. As nobody is mentioning it ,am I to assume that there is no relay or fuse or fusible link for the headlights on these as I was logically assuming?

Good idea about changing out the front tires to the rear. I'll add that to my short list. I've driven it a couple days now around the farm and it starts on the first pop and really drives nice. The air system has me a little unsure as sometimes it pressures up to, and stays, within a range between 90 and 120. However, other times it will seem unable to build more than about 60 and occassionally will even drop low enough to trigger the buzzer? Steering the little beastie at those times is challlenging

The air escaping that I mentioned originally (at Ft. Hood) was coming from behind a single rear tire and it was blowing enough to blow your hair. I don't yet have a grasp of how the air gets from the axle supply line to the outside of the wheel (through the hub, etc.). And, I haven't even looked to see where it may be coming from because I am dreading turning the CTIS back on as I'm assuming it will deflate my tires some. But, I will as soon as I get a chance. I won't be at all surprised to find a broken (or disconnected) air fitting on that tire.

Lastly, one of the little plastic air hose fittings that attaches to the winch solenoid is broken off. Can anyone give me a tip on where someone would go to find this type of fitting?

Thanks,
Ross

 

[rossbart]

Ditto on switching out the front tires to the rear. I had a blow out during my A3 recovery. Fortunately, it was on the rear, but it was still bad. I would highly recommend changing out the motor oil in the Allison for Dexron III. Use the drain and fill technique and change out both internal and external filters. The A3 external transmission filters have a habit of coming loose and leaking fluid. Don't get tempted to overtighten it, just check it often.

Oh, and BTW: I have all of the filters (my tranny filter is leaking slightly right now) and I'll be swapping over to Transynd as soon as my 5 gallons comes in at the local parts store.

Ross

 

[unispeed]

Ross They are called instatube fitting
I use mcmaster http://www.mcmaster.com/#instant-tube-fittings/=ewrm3i
convert to brass it is worth the extra 2 bucks your hose is 1/4" od
Mark

 

[BadMastard]

Hope I can help. Try carquest or naps for the fitting. Look in the air brakes catalog or section, that's where I find most of mine. Air that strong coming from the tire area is probably the hub line disconnecteded, but should be easy to see with the tire off. Air pressure might be your steering. Watch your gauge while turning the tires lock to lock. If it drops rapidly, there you go. There is an air line by the tire driver front tire from near the steering knuckle. Hit it with soapy water. Mine leaked like a leaky thing. Get your meter out for the headlights. Check the wires at the headlight. It will be obvious. Could be the high beam switch too. Check the pumpkins for gear oil. Bad ctis can blow it right out. Good luck!

 

[rossbart]

Hope I can help. Try carquest or naps for the fitting. Look in the air brakes catalog or section, that's where I find most of mine. Air that strong coming from the tire area is probably the hub line disconnecteded, but should be easy to see with the tire off. Air pressure might be your steering. Watch your gauge while turning the tires lock to lock. If it drops rapidly, there you go. There is an air line by the tire driver front tire from near the steering knuckle. Hit it with soapy water. Mine leaked like a leaky thing. Get your meter out for the headlights. Check the wires at the headlight. It will be obvious. Could be the high beam switch too. Check the pumpkins for gear oil. Bad ctis can blow it right out. Good luck!

BadMastard,

I do have air (sporadically) coming from the steering air pressure regulator on the drivers side frame rail. I blows a great volume out of the hole in the bottom of the cover (if it's on) or just around the top of the knob if its off. Of course, I don't know how it's SUPPOSED to work - maybe this is normal? So, just out of curiosity I just closed the air petcock on the firewall going to the steering system to see if she would build (and hold) air better with the steering system bypassed. Sure enough, as soon as i started it with the steering air shut off the guage quickly built to 120 psi and stayed there - no more air problems. Unfortunately, no power steering either (which is problematic with those big 14.5r20's).

My question(s): is air supposed to be coming out of the regulator or is it broken? If broken, do you suggest replacing it or just bypassing it. What would the pros and cons be of just bypassing it and letting the steering system have unregulated air pressure?

Thanks again,
Ross

 

[AceHigh]

Rossbart, I have two trucks with no regulators. I got the bypass parts at Lowes.

The regulators seem to serve almost no purpose as these units are designed to use on trucks with up to 250 psi and ours only run up to 130.