Allison 3000 vs 4000 series

[sirpurrcival]

I was at an RV show last weekend and one of the salesmen was talking about Allison Transmissions. He was saying that the 3000 series and the 4000 series are basically the same beast but that there are some additional cooling and maybe a few other minor differences.

Is there a big difference between the series and should I be looking for a rig with one over and above the other?

[observer]

The big difference is the amount of torque that the transmission can handle. The 3000 can handle 1250 lb/ft of torque. The 4000 can handle 1950 lb/ft. The motorhome manufacturer will mate the proper engine and transmission combination. The 4000 is used with high horsepower engines

[Steve Ownby]

They are different in size and power handling capacity. The 3000 weighs about 530 lbs and the 4000 weighs about 830 lbs. The 3000 holds about 26 qts of fluid and the 4000 holds about 40 qts. The 3000 has a horsepower max of 450 and the 4000 has a horsepower max of 650.

They are both 6 speed transmissions and the two top gears are overdrive. You don't choose the transmission series, you choose the engine and the mated transmission will matched to the max output of that engine.

Both transmissions are close to bulletproof when well maintained. The salesman was ill informed.

[sirpurrcival]

Thank you gentlemen. That is very helpful.

[edgray]

Quote:

Originally Posted by sirpurrcival I was at an RV show last weekend and one of the salesmen was talking about Allison Transmissions. He was saying that the 3000 series and the 4000 series are basically the same beast but that there are some additional cooling and maybe a few other minor differences. Is there a big difference between the series and should I be looking for a rig with one over and above the other?

YES, they ARE the "same beast", just as are the Toyota Prius and the Toyota Tundra.

The info provided by the posters upthread is correct, NOT what the salesman said. He apparently needs to learn a bit more about what he sells, before speaking.
Ed

[sirpurrcival]

And that is why I come here. Where there is a wealth of information from people who drive big rigs and have the experience. I learned long ago that one should always seek second and third opinions.