Good evening. We just came back from our maiden voyage in our "new" 1990 Breakaway.Everything went well except for the HI TRANS TEMP light coming on. We went thru the White Moutains of New Hampshire going south and thru the Green Moutains of Vermont coming north. For people not familiar with the area, there is quite steep hills on these highways. Once going south and once coming north there is a very steep hill. The one going north is several miles long and peak at 1856 feet. Truck drivers reach the top at about 35MPH with their emergency flashers on. On both case the light went on along with the Low Pressure light. The engine temperature was about normal around 200 deg F. On both case, I immediately stopped on the shoulder, idled for a couple minutes and shut everything off after for about 20-30 minutes. After that, I restarted, completed the hill and had no further problem for the rest of the day.
My Barth is a 30' Breakaway with the 5.9L Cummings coupled to the 4-speed Allison.
I checked the transmission oil level while running at idle in neutral and it was full. I never went over 2000RPM during the trip, and let it slow down to 1500RPM during that climb.

My questions are:

Is this something to expect from now on (on steep hill)?
I never thought of downshifting while climbing. Would that have helped? Do you normally downshift while climbing?
Do I need a bigger oil cooler on the transmission? Is that something you have upgraded to?

Other than that the trip was a real pleasure.

Real Lalonde

It's normal for the transmission temp to climb on a steep grade.

Of course, the question is, at what temp does the light come on? I'd suggest replacing the light with a gauge - the wiring's already there, and a gauge will run about $70-80 with its sender.

I put an aftermarket pan on my transmission from Mag-HyTec, and the extra capacity (about 4 qts.), and the cooling fins and internal baffles make quite a difference.

I never thought of downshifting while climbing. Would that have helped? Do you normally downshift while climbing?

Were you climbing with the "cruise control" activated? If so, turn it off and use the foot feed (yeah, that's what we call it in Texas); downshift when/if necessary. The only "overheat warning alarm" I ever suffered was while trying to climb a long Nevada grade on cruise; since, I drive -and downshift- as required on steep/long grades.

quote:

My Barth is a 30' Breakaway with the 5.9L Cummings

1992 and earlier breakaways with the 5.9 Cummins use the 542 allison. This transmission has no lockup torque convertor and I can't find one in the aftermarket.

Therefore this transmission builds a lot of heat climbing hills. 1993 and later use the allison 3060 and don't have this problem.

Gary Carter

I don't know of any transmission that doesn't unlock the torque converter before downshifting, nor any that would lock the converter on a strenuous hill climb. So there must be design enhancements to the 3050 that cool it better than the 542.

That said, I still favor a gauge over a light. I want to know what the transmission's doing, not what it's already done...

Hi Rusty, as a follow up to my adventure, I had the transmission oil and both filters replaced. Just came back from a 400 miles trip thru the Laurentians mountains over the weekend with no problem. There is 2 things I want to do still.

One is to replace the light with a gauge. You mentionned that the wiring is already there. Is that the wiring coming to the light that you use?

The other is to replace the cooler with a bigger one. I've seen suggestions for model numbers somewhere else on this site and I will follow these sugggestions.

Real

Yep, you can use the wire now attached to the sender at the transmission and the light at the instrument panel. No need to run another wire.

quote:

Originally posted by Rusty:
I put an aftermarket pan on my transmission from Mag-HyTec, and the extra capacity (about 4 qts.), and the cooling fins and internal baffles make quite a difference.

Rusty, what temps were you showing before and after? After temps stabilized, I mean. The larger capacity would get you up shorter hills better, of course, but I am interested in the cooling effect of the pan. I like the idea that they have fins or baffles inside to carry more heat to the outside. I have a truck that might need one of those.

I didn't have a gauge on the old pan (the Mag-HyTec has a fitting), but the big thing I noticed was that the engine coolant rose far less (and far less quickly) when the torque converter unlocked on climbing a long grade.

Mag-HyTec suggests that tranny temp will be lowered by 20F, typically, but talking with the Rothlisbergers, I'm the pioneer for installing the kits on a motorhome (at least with the 4L80E and the Dana 80); pan S/N was 2574, diffy was 297.

These items were extrordinarily well finished, and the fit was precise. I'd have no hesitation in recommending them to anyone using the drivetrain to push/pull anything more than an unloaded pickup.

quote:

Originally posted by Rusty:
the big thing I noticed was that the engine coolant rose far less (and far less quickly) when the torque converter unlocked on climbing a long grade.

Thanks, that is quite a recommendation. Think I'm gonna put one on the list.