I plan on changing transmissions this winter. I really want to get rid of the 542. Tired of the overhead buzzer going off in the mountains, plus I want to boost the HP the the cummins to about 275hp.
Looking at the Aisin A581, Allison 3000 and Allison 2000. My question deals with the latter. I have found a number of used 2000 but they all are off Chev gas engines. Our Cummins has a SAE #3 bellhousing, but Allison only lists SAE #3 and SAE #2 bell housings. Looking at the pictures of the 2000 they appear to have an adapter ring.
So does anyone know what is involved in hooking a former gas 2000 to a Cummins 6B? I kinda like the 2000 as it is about 200 pounds lighter than the 3000 series.

The biggest issue will probably be ratios. If it is for a gas engine, chances are the ratios will favor high reving and not give you what you want. The MD3060 that is in mine has two overdrive ratios, both 5th and 6th.

If it (Allison 2000) is lighter then the gears and bands will be lighter duty as they can be if the RPM range is higher and less torque is transmitted. Oil capacity will probably be less also.

As you probably already know the Cummins is a huge torque monster and if you are planning to increase the power will be even more so. I definitely would not consider anything other then a MD3060.



Do you know what rear end ratio you have? Mine is 4.1 and is a Eaton 15040S, much heavier duty then the Dana 80.

I'm really speaking out of school here, since I've not been tracking Allison tranny data, but AFAIK, the 2000 gasser is just that - for a gaso pickemup; it's not in the same league as the 3000 series. The tranny furnished with the diesel pickups may be a different design, however.

In any event, for something as vital as a drivetrain thingy, and based on your desire to boost the 6B to 275 HP (with the parallel increase in torque), I'd not want to put a wimp into the drivetrain. Even the 4L80E tranny in my Breakaway, rated at 10% more torque than the AMG engine can muster, was replaced with an heavy-duty one with even more headroom.

And, one would wonder why you're getting alarms (over-temp?) on the 542...I suspect that a pure tranny swap isn't going to rid you of that issue. So, first, I'd determine why the 542 wants to overtemp, before even considering a swap. And 200 lbs. in an 18,000 lb. motorhome will be neglible. And as MWrench pointed out - what's your diffy? The Dana 80 (in mine) is a hoss, but could it handle the proposed drivetrain?

FWIW, I would guess that correcting the overtemp issue in the 542 would make you much more content with the current specs; more HP/torque won't do any good if it can't be laid onto the road...

$$$$$$ If you want to go on the cheap, you can fix the hot 542 relatively inexpensively. I converted my 542 to basically a 545 by putting on a conversion kit from Allison. The 542 has a little oil pan and therefore gets hot. By putting on a 545 pan you increase the amount of fluid by a couple gallons or so (you must be sure you have the road clearance). You can also probably add a transmission cooler to be sure. However, I have also been told by Allison that the 542 is rated to 240hp max. I put a Banks kit on my 5.9 and had no problems, the coach could really go, but i never put my foot all the way in it. Just my two cents.

Tom

Should have mentioned also the Allison 643 was a tranny that the Allison guy recommended to me if I had wanted to ditch the 542.
Tom

Tom, what type of Barth do you have? and the year?

Was it expensive to do?

It is something that I would interested to do since my Breakaway 542 transmission has a tendency to heat on long uphill roads.

For those that do not know, the 542/545 has no lockup torque convertor and the speed on a mountain grade can drip 10mph with out losing any engine rpm.
Also the 2000 is offered by many mfgers, including Ford 600s, with the Cummins engine. It is also the transmission behind the DuraMax.
Third there is the length issue. The 64? is to long. We hardly have a drive shaft now.
And for you trivia buffs, there was also a 1542/1545. This transmission locked up in third and fourth gear. If I could find one, I would take it.
So anyway we are back to the bell housing issue.

Haven't done any research on compatible Allison transmission so my comments are limited.

Sounds like there is no transmission cooler on your 542, on mine there is a huge transmission cooler as part of the radiator package along with the turbo intercooler.

I don't have a trans temp gauge yet (there is a monitor in the electronic control for the MD3060) but have mounted several temperature recoding strips on the trans case, even in 110+ degrees going up grade (to Las Vegas) I have never had an alarm and the strips do not indicate any severe temperature.

Your engine must be mounted further forward then mine, with the 6 speed Allison which is very long I have a small driveline also, I have to measure to see just how long but it is short. Just a slight compression of the forward engine mounts resulted in an unacceptable "U" joint angle. The 6 speed Allison also hangs way down, probably 4-6 inches below the engine pan, better now that there are new isolators installed.

Real,
I am a Barth wannabe, the coach I converted is a SOB 34 ft with a B5.9 190hp coupled to a 542. However, the conversion is simple, no more than draining your transmission fluid, removing the oil pan, removing the 4 bolts on the filter, and reversing the process with a new filter and bigger pan. I figured the new pan was appr. 4 inches closer to the pavement than the old one. The cost of the new pan and filter was around $125 from Allison. The cost of the fluid, "priceless".

Tom

Look into a lockable torque converter to replace the one in it now. Take the 542 and have it rebuilt and beefed up by someone whom specialzes in beefing up transmissions. You'll kill two birds with one stone and saved a ton of cash. Install a new oil cooler pan and also an external coiling coil. This would be my approach .