M35A3 engine stall

[goodguyzy]

testing the brakes on packed snow today and noticed in 3rd gear, not in lower gears, that when i lock up the brakes and came to a stop the engine will die. don't know much on the A3 yet and am not a expert on automatic transmissions. any input would be appreciated

 

[Westech]

That was a problem with the first batch of 900's until they were made with ABS brakes. What happens is when you lock up the brakes the trans done not have enough time to down shift and stalls the engine. Kinda like leaving a Manual transmission car in gear and slamming on the brakes.

 

[mktopside]

IIRC it talks about this happening in the TM. That trans doesn't mess around when it comes to staying in gear.

For what it's worth I asked the local large diesel shop today what they charge for a 3116 500hr service they said $600. I also asked them if they could adjust the trans with their magic Allison machine, they said they could set the shift points to wherever you want, but going on the allison adjustment machine if it needs it costs $950! I got the impression that they could adjust the shift points for less and it didn't require the special machine.

 

[goodguyzy]

i haven't had any service done yet, and yes i may have to take out a loan to have it done, one of the cons of owning an A3

 

[WillWagner]

That's because the trans is in lock up. Just like if it had a manual trans and you locked the wheels w/o depressing the clutch. Changing shift points or adding/removing a gear requires the Allison program and a calibration of the TCU.

 

[mktopside]

i haven't had any service done yet, and yes i may have to take out a loan to have it done, one of the cons of owning an A3

I dunno if I would spend the money on the adjustment without knowing more about it, or unless there was an actual problem. I think it's safe to say that it's normal for the 1545 to shift like poop, however the shift points of the trans, and the HP of the engine seem to be pretty well balanced for leaving from a stop with a load, and for the top speed of the truck...... not that this balance is a good thing, it just seems to me that it's all intentional.

I have had my A3 for about a month, and have been daily driving it for the past two weeks (40 miles each way to work, parts of it are heavy rush hour DC Metro area traffic). No, it's not exactly economical, and I've been eating through gas, but I really wanted to give the truck a good shake down, bring any problems to the surface, and learn how it drives backwards and forwards.

When I first got it scared me in a few ways, but now that I've been driving it for a while it's actually pretty easy to drive, and I can swing it into some pretty tight spots.

One thing that I have noticed relating to the trans is it's ability to slow the truck down. Unless someone stops short in front of me, I rarely have to use the brakes other than to stop the truck at a very slow speed. If you let off the gas far enough away the 1545 will start down shifting on it's own, and will bring the truck to about 5mph after it downshifts to 1st. I like the trans in this case.

Another thing that might make yours feel better is to change out the fluid. Go buy 8 gallons of Dex III, drain what's in the pan, fill with 2.5 gallons, run it up to temp, drain what's in the pan, fill with 2.5 gallons, run it up to temp; do this one more time, and if you bought a new filter change that last. Before you do so, find the vent line on the back of the cab and blow it out with a bit of compressed air. Mine was clogged and when I went to fill the trans it turned into a very messy production. My trans feels like it is getting better every day after getting rid of the 15w40.

I do wish it had a 5th gear, or a slightly over driven 4th. ("Speed Nazi's", "Braking force Nazi's", "Don't go over 50mph Nazi's" be quiet). Being able to go 60mph at redline would be nice, but I don't like having to be so close to redline just to go 50mph. If I could keep it below 2500 and do 50 I'd be really happy. $950 could go a long way towards paying for a replacement trans that has some overdrive ability. I appreciate the beefyness of the 1545....... but at the end of the day it forces you to drive around at redline on all but the slowest roads.

I wonder if anyone could work a slight overdrive into the high range of the T-case? I don't think it would hurt you too much leaving from a stop since 1st gear is so low and slow; and it would make all the difference in the world for normal driving.

 

[goodguyzy]

thanks for the advise. Yes the top speed sucks but I am checking into a gear splitter but not having much luck on finding a source or any prices.

 

[flyxpl]

I think I will try 395's for a bit more speed . if I could get 5 mph more I would be happy .
Unloaded I would like my tranny to shift a little bit earlier . Tranny definitely slows the truck down without brakes .
I am about due for some tires so the money is going to have to be spent weather I go stock or 395's

 

[lonegunman]

I too wish it would go 60 but it don't. That being said, spending a ton of money for 7-10 mph seems pretty pointless. I get right at 50mph @2550rpm or so.

I got my 500 hour work done for about half of the first quote. Maybe a little shopping around? It can't hurt to ask for the cash price or weekend discount, especially if you can talk face to face with the guy working on your truck.

 

[mktopside]

I too wish it would go 60 but it don't. That being said, spending a ton of money for 7-10 mph seems pretty pointless. I get right at 50mph @2550rpm or so.

I got my 500 hour work done for about half of the first quote. Maybe a little shopping around? It can't hurt to ask for the cash price or weekend discount, especially if you can talk face to face with the guy working on your truck.

For me, I don't really "need" to ever go more than 50, I would just like to be at a lower rpm at 50 than I am currently. With as fast as this thing drinks gas I'm sure it wouldn't take very long to pay for itself in gas mileage alone. Then again, I am just "assuming" it will use less gas at a lower rpm, I really don't know.

I'll shop around a bit on the price, but labor rates vary wildly depending on where you are. Did you notice anything different about the truck after the service? Does it run better? Just curious.

 

[mktopside]

thanks for the advise. Yes the top speed sucks but I am checking into a gear splitter but not having much luck on finding a source or any prices.

I'd love to throw a gear splitter in the truck, but I too looked around a good bit online and couldn't really find anything. Let me know if you have any luck.

 

[mktopside]

I think I will try 395's for a bit more speed . if I could get 5 mph more I would be happy .
Unloaded I would like my tranny to shift a little bit earlier . Tranny definitely slows the truck down without brakes .
I am about due for some tires so the money is going to have to be spent weather I go stock or 395's

Will 395's fit on the rear?

 

[Floridianson]

Just put in netrual if you can't stop slowley to let her downshift. I give the my A3 a lot of room and let off the peddel early and let it do it's thing.

 

[lonegunman]

For me, I don't really "need" to ever go more than 50, I would just like to be at a lower rpm at 50 than I am currently. With as fast as this thing drinks gas I'm sure it wouldn't take very long to pay for itself in gas mileage alone. Then again, I am just "assuming" it will use less gas at a lower rpm, I really don't know.

I'll shop around a bit on the price, but labor rates vary wildly depending on where you are. Did you notice anything different about the truck after the service? Does it run better? Just curious.

After the service it just seemed like it had a lot quicker throttle response, a bit more torque and idled better. The guy who worked on it, loved it and was suprised how great it ran. He was a long time Cat mechanic and knew about the problems with the 3116 engines. All of the specs were in their computer. The engine was new for all intents and purposes.

I had them verify the tac and it was on the money, the engine revved to spec, which was a red line of 2925rpm according to Cat. They did a chasis service and R&R'd the axle grease as well.

I had them do more than usual because I was driving it cross country. It used less than a quart of oil over the 2600 miles I drove it home. Most of the oil was from a small leak under the compressor that cannot be addresed without removing the compressor and the injector pump. I agree with the Cat guys when they said it was more expensive to fix that leak than it is worth, for the price of an annual quart of oil, who really cares.

 

[mktopside]

After the service it just seemed like it had a lot quicker throttle response, a bit more torque and idled better. The guy who worked on it, loved it and was suprised how great it ran. He was a long time Cat mechanic and knew about the problems with the 3116 engines. All of the specs were in their computer. The engine was new for all intents and purposes.

I had them verify the tac and it was on the money, the engine revved to spec, which was a red line of 2925rpm according to Cat. They did a chasis service and R&R'd the axle grease as well.

I had them do more than usual because I was driving it cross country. It used less than a quart of oil over the 2600 miles I drove it home. Most of the oil was from a small leak under the compressor that cannot be addresed without removing the compressor and the injector pump. I agree with the Cat guys when they said it was more expensive to fix that leak than it is worth, for the price of an annual quart of oil, who really cares.

Thanks for the reply!

By axle grease do you mean the gear oil in the diffs? or did they repack the wheel bearings? What did that portion of the service run just for reference?

I'm going to shop around a bit. I have a buddy who has the rack tools, but I'd rather have someone who knows the ins and outs of the motor do it, in case they see anything else of concern.

I agree with not pulling the compressor, oil is cheap and unless it's pouring out faster than it can be poured in I wouldn't sweat it.

 

[goodguyzy]

I too wish it would go 60 but it don't. That being said, spending a ton of money for 7-10 mph seems pretty pointless. I get right at 50mph @2550rpm or so.

I am going to spend the extra money for a gear splitter if i can find one, about 2k from what i hear. 50mph is to slow for me and everyone behind me pissed off.

 

[mktopside]

For $2k I wonder what other auto transmissions could be had used?

Id shell out $2k for a splitter if it was a reasonably trouble free install. But if I have to do a ton of fabing and welding, other than the drive shafts I might think twice.

 

[goodguyzy]

take a look at the pics of Erik's from Erik's military surplus, looks pretty straightforward.
I now declare this thread to be a M35A3 general discussion forum.

 

[mktopside]

Hahaha, they all seem to turn out that way. We have to find theseittle corners of the site to hide from the haters!

I saw the one on eriks site, and it does look easy. I wish he sold it!

Since this is now a general thread. I replaced my flasher unit tonight that I got from eriks, flashers work perfect now!

 

[goodguyzy]

what was wrong with the old one? when i got mine the headlights where missing and turn signal assembly. got them at Erik's, same stuff as the A2, don't know why they got robbed.