M35A3 Owners unite

glcaines

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When I drained the oil the first time, it seemed to be pure ATF (albeit burned). Is there a good way to clean the system without draining multiple and filling times?
Was it motor oil or ATF? When ATF is burned, or dark brown in color, its a bad sign for transmission health. It normally means that clutches have been slipping. Whatever else you do, you need to make absolutely certain that the transmission is purged completely of motor oil if you switch to Dexron III. Dexron III is not compatible with motor oil. When I switched to Dexron III with the drain and flush technique, I was happy that I did it myself because I was certain that I did it right. Also make certain that if you switch you only switch to Dexron III. Later versions of Dexron ATF are not compatible with some of the o-rings and seals in the transmission.
 

Potluckslammy

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I had recently asked in another thread if it was appropriate to flush the tranny with diesel fuel, as one might do to a differential, or manual type transmission. I got one well considered reply from glcaines, thank you very much, BTW. Maybe I can get more input if I ask here. Opinions?
 

bushw

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Was it motor oil or ATF? When ATF is burned, or dark brown in color, its a bad sign for transmission health. It normally means that clutches have been slipping. Whatever else you do, you need to make absolutely certain that the transmission is purged completely of motor oil if you switch to Dexron III. Dexron III is not compatible with motor oil. When I switched to Dexron III with the drain and flush technique, I was happy that I did it myself because I was certain that I did it right. Also make certain that if you switch you only switch to Dexron III. Later versions of Dexron ATF are not compatible with some of the o-rings and seals in the transmission.
It was definitely burned ATF. The tranny shifts well overall, except when shifting from 3rd to 4th (35 MPH). At this point it just hangs there and at times will not shift no matter what I try. Occasionally it'll shift if I let off and coast for 10 seconds or so. I am starting to wonder if there is oil caught somewhere in the valve body. The other question is: At what temperature should the transmission run at? Thanks!
 

HDN

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I've discovered in my wheel work so far that the wheel weights are mounted inconsistently, and the TM doesn't help much either. On some wheels they're on the 3rd stud CCW from the air pipe, and on some wheels they're on the 4th stud CCW from the air pipe.

I took a closer look at the TM wheel drawings and it looks like it should be on that 4th CCW stud. That stud is also more opposite of the CTIS valve.
 

fuzzytoaster

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I'm having to troubleshoot crank no starts at the moment. One is electrical and the other is missing the fuel tank pick up tube and check valve. Does anyone have a parts truck? My marts truck doesn't have a fuel tank which is totally Murphy on that one. 😅
 

tobyS

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Welcome to the club! Do you know if they came out of the service in that green? I usually don't see A3s in plain OD.
My A3 was Navy and solid green. Had a shark on the door that is part of "Coastal Warfare Unit" ( which I will restore (with big teeth)).

Set up a tank to bypass all of the OEM fuel lines. Like up on the cowl, so no pump.

You know the transmission history with this model?

I'm still looking for a driver seat base for A3.
 
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HDN

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My A3 was Navy and solid green. Had a shark on the door that is part of "Coastal Warfare Unit" ( which I will restore (with big teeth)).

Set up a tank to bypass all of the OEM fuel lines. Like up on the cowl, so no pump.

You know the transmission history with this model?

I'm still looking for a driver seat base for A3.
That's pretty awesome! What are the truck S/Ns? I'm curious how late in production they were built and if other Navy A3s were built in the same run.

The issues with the AT1545 are well-documented around the forum. The main issue has to do with the control pistons (I think) that control 4th and reverse gears. They either get pulverized or the seals give out, causing the loss of 4th and reverse. This seems to be attributed to additional stress caused by the locking torque converter, which the AT545 it's based on probably wasn't designed with that in mind. I'm thinking if one follows the data plate and doesn't load the truck over 2.5 tons (no doubling for improved roads like the A2), it'll probably work well for a long time. If the pistons do go kaput, they can be replaced with the ones used in the 4L80E found in HMMWVs and GM trucks, which happen to be stronger than what the AT1545 comes with.

The military seemed to be concerned enough about the AT1545 that their maintenance TM includes instructions for swapping it with the more-common AT545, which has been used in many medium-duty trucks and school buses. It'll just get worse fuel efficiency because the AT545 doesn't have a locking torque converter, but at least it'll keep your truck moving!
 

tobyS

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I wish I had known about the 4l80 race clutch and vulcanized piston when we rebuilt mine. I don't know anyone that has done it yet....we put in the OEM.

First thing I would do if I had it (making 4 x 4) to do again is get 5.90 gears. And locking diff.
 
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HDN

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It just occurred to me that I got @tobyS confused with @fuzzytoaster , which I realized when tobyS' signature line mentioned the 4x4 A3 :p Navy A3s are news to me, but I'm still an A3 newbie :p

There's a Mission BBQ that's going to open soon in Henrietta, NY, and they have an M35A3 parked outside of the restaurant with a BBQ pit in its bed. CTIS was removed and it has 395s mounted. I'll try to get a picture of it the next time I see it.

I'm surprised how common these trucks seem to be considering only about 5,800 were built. I know of six other than mine within a 1-hour drive of my home. I can't say the same about the A2s or any of the 5-tons or FMTV.
 

HDN

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Tire Dismounting on A3 Using Tractor With Forks

I finally got around to dismounting my passenger side rear tire on my A3 today. I don't know how anyone does this without a tractor with forks. It makes the job extremely easy, both dismounting and remounting. Unfortunately, in my case I discovered that my wheel was severely damaged by corrosion. No damage was visible from the exterior. The lip that seals against the O-ring was corroded to the point that about 1/16" of metal was missing for about 5 inches. The rest of the inside of the wheel halves was also severely corroded. I also found the valve stem grommet rotten with the nut finger-tight, which seems to be the standard condition for those grommets on A3 wheels. Fortunately, I already had an almost new complete A3 wheel that I was able to use. New grommet, new O-ring, some tire mounting lube, and I was back in business. Now I think I'll look for another A3 wheel to keep if needed in the future.
Is there risk damaging the exposed threaded part of the rim air tube dismounting the tire this way? I was thinking about ways to make this part of the tire dismount easier and can't help but think the tire bead may damage the air pipe where it gets bolted to the rim.

The last tire I did I Sawzalled a hole in the side wall to remove the nut holding the air pipe on thinking that was hanging up on the bead, then flipped the wheel right-side up on stacked 6x6s and jumped on the rim until it popped out. Turns out a warped bead lock insert was jamming up the process!
 

HDN

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If you are careful there is minimal risk of damaging anything doing the dismount with tractor forks. I've done several tires this way and not had any problems.
Do you remember if you manually pried the bead around the pipe stub, or did the bead just pop over it? My hope is that I could just jump on the rim again and have it just pop off with the bead popping over the pipe stub without getting caught on it and causing damage.

The first wheel I did I had it upside down on some blocks and eased it off with a pair of big pry bars, prying the bead around the pipe stub. It took this newbie probably a half-hour to an hour of doing that to get the rim and tire separated.
 

tobyS

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I replaced the valve stem with Haltec big bore system and can change the stem from the outside for dish out on the rear and dish in on the front. It won't hang up on the inside and they seal fine.
 

glcaines

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Do you remember if you manually pried the bead around the pipe stub, or did the bead just pop over it? My hope is that I could just jump on the rim again and have it just pop off with the bead popping over the pipe stub without getting caught on it and causing damage.

The first wheel I did I had it upside down on some blocks and eased it off with a pair of big pry bars, prying the bead around the pipe stub. It took this newbie probably a half-hour to an hour of doing that to get the rim and tire separated.
I used a very large pry bar and it came over it very easily on all the tires. I did pour tire lube over the area before prying, however. No damage to any tires. I was very lucky in that I inherited a lot of truck tire changing tools from my Grandfather that date back to the 1930s. Very handy sometimes.
 
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