Navistar engines and Allison's to avoid?

[Renze]

Allison is really a work of art in transmissions. With their retarders that can rival a jake brake in braking horsepower, downshift capability, push-button gear selector boxes and lock up gears, it's no wonder they lead the world in heavy truck autoshift transmissions and no wonder companies like Ford & IH buy automatic transmissions from them instead of building their own.

In Europe you only see Allisons in firetrucks. Even in recent years, Volvo I-shift, and ZF AS-tronic have become very popular, but they are still electronic gearshifters, not true automatics like a converter transmission. They dont loose any power in a converter at all, but having driven them on the yard, i dont like them for manoevering in tight spots, or start-stop jobs because you control the clutch with the gas pedal, which is just a funny, uncontrolled feeling.

 

[wushaw]

I use brake/fuel pedal kinda like clutch and gas on my Pete, it has the 12spd Meritor Freedomline tranny.
It does take some getting used to.

 

[Builder]

Thanks for chiming in Builder. I gotta' nominate you for the resident Navistar expert after reading all of that.

Thanks for the nomination, but an expert, I am not.

I'm just a good ol country boy giving up all the knowledge I have to those who seek it.

There's plenty of "experts" here , but I'm not one of them.

 

[QRTRHRS]

(Hopefully) I will never own another manual transmission in a MD/HD in my life. Allison has proven tests that show their transmissions make a truck faster than even the most professional driver can shift a manual transmission. They actually sponsored a "showdown" between trucks to prove it. With more lock up gears, fuel mileage & power transmission is almost the same now as a manual in medium duty trucks, maybe better now that they have double O/D's.

When I'm done work, the last thing I feel like doing is working my truck on the way home, especially while towing. In snow, they don't break traction like a manual.

Allison is really a work of art in transmissions. With their retarders that can rival a jake brake in braking horsepower, downshift capability, push-button gear selector boxes and lock up gears, it's no wonder they lead the world in heavy truck autoshift transmissions and no wonder companies like Ford & IH buy automatic transmissions from them instead of building their own.

Builder, the biggest truck with an auto that I ever drove was a Penske box rental so I guess I may be out of touch. On one hand, having a good number of New York state and Canada winter miles under my belt, I guess I would like to see how they do in the snow. On the other, I don't care if I ever see another iced over road again. At least one that was not clear by noon time, lol!

Based on automatic cars and pickups, I never felt that I could feel the road like I can with a stick.

Does the auto in your dump ******? If so, better than an exhaust retarder? Most of the Cummins engines I that drove with engine brakes garnered respect on a slippery road. Where as on the C15 CAT's or Detroit's, they never had that same level of restriction.

Anyway, I was looking at an ad for a 2000 4900 that states that the auto is a MT-643. Is that a misnomer or is there such a number? This one has a DT466E rated 195hp. It's a good days drive for me so I don't know if I will get to check it out or not.

 

[DieselPower]

Builder, the biggest truck with an auto that I ever drove was a Penske box rental so I guess I may be out of touch. On one hand, having a good number of New York state and Canada winter miles under my belt, I guess I would like to see how they do in the snow. On the other, I don't care if I ever see another iced over road again. At least one that was not clear by noon time, lol!

Based on automatic cars and pickups, I never felt that I could feel the road like I can with a stick.

Does the auto in your dump ******? If so, better than an exhaust retarder? Most of the Cummins engines I that drove with engine brakes garnered respect on a slippery road. Where as on the C15 CAT's or Detroit's, they never had that same level of restriction.

Anyway, I was looking at an ad for a 2000 4900 that states that the auto is a MT-643. Is that a misnomer or is there such a number? This one has a DT466E rated 195hp. It's a good days drive for me so I don't know if I will get to check it out or not.

If it has a MT series in it (there is such a beast) it is much more desirable than the AT series. The MT is much like the AT series but on a massive dose of steroids. MT's were commonly found in severe applications like trash trucks where they take a real beating. In a trash truck a AT would be nothing more than a hand grenade with the pin already pulled just waiting to blow.

Allison makes some very large automatic transmissions these day's. It's not uncommon to find them behind 500 HP+ engines. Don't see them in many road tractors but I have seen them in a fair number of concrete mixer trucks and dump trucks.

Personally I hate automatic transmissions. A good friend of mine got a older 4900 International with a DT466 (non electronic) in it and hated it. Did a 10 speed RoadRanger tranny swap and it is now a beast. It couldn't get out of it's own way before and had horrible fuel economy. The newer electronic Allison's have come a long way over there older counterparts. I'm just accustomed to driving larger non synchronized transmissions and kind of feel naked without a shifter sticking out of the floor.