Trans temp on new fleetwood 40x

[et2]

I'm trying to get a base line on the Allison tran temp. Off highway 170 - 180. Highway flat and level 190 - 200. I've seen it higher than the engine temp for a very short period. Is this normal on relatively flag highway? What's too high? The outside temp was around 86 today. Cruise was set at 61 and the economy setting on the trans. I think 199 - 200 is too high. Anything to be concerned about?

[siggyd777]

Considering the outside temp. of 86F, your temp's look about the same
as what I see on my MH.
Siggy

[wolfe10]

The issue is reasonably complex. There is no single "approved" location for the transmission temperature sensor. Some are in transmission itself, some on line IN on the transmission cooler and some on the OUT line from the transmission cooler.

And, the Allison 3000 and 4000 series transmission's torque converters are locked up in "high" second and always locked in all higher gears.

So, transmission temperature is really a combination of heat produce in the transmission and in most applications also heat picked up/not dissipated by the in-radiator transmission cooler.

But, bottom line, your temperatures are in the normal range.

[et2]

Thanks to all. Looks like its normal. I will just keep an eye on it.

[Acampingwewillg]

My Allison(HD-4060) runs at about 200-220 and has since Ive owned it(11 years). Ive changed to synthetic trans fluid completely and my owners manual states my temps are within spec's. It even considers 250 to be OK for short periods of time and as high as 300 before you need to worry about shut-down.
Ive come close to that 300 figure coming down a mountain pass with the Jake brake on and tranny downshifting to hold speed, then running into stop and go traffic in 100 plus degree weather. No ill effects so far, knock on wood.

[dubdub07]

et2,
I have the same chassis, engine, and tranny. In the mountains with a toad I see around 200 on a sunny day and even though the air is cooler at 9k feet, the grades are murder. They still stay around 200. In contrast on the same passes, my Ram 3500 would run around 230. My 2007 ran around 240 on the same passes. So I thought 200 was pretty darn cool!

I called the dealer on my Ram and they said that boiling point is around 315 for tranny fluid, so 240 wasn't high enough to worry about.

WW

[Trackrig]

I have a Scangauge on my 2005 Fleetwood 39S. I'm running synthetic in the transmission. It's interesting the watch the Scangauge. It will show the air intake temperature - as it goes up, so does the transmission temperature. On a flat highway with an air temp of 86 at about 62 - 63 mph, my transmission temp is more around 180. I'm not saying yours is too high, but mine is cooler. I've very seldom seen mine hit 200; I think the highest I've seen in the mountains in Canada was 206. I'm pulling a Jeep Wrangle and travel with a full tank of water since we never know where we'll stop.

Bill

[hmknightnc]

I don't know about an allison in big diesel pusher but all my transmissions run about 175-180 unloaded and cruising, about 190-200 if loaded heavy cruising (so yours sounds normal to me). I don't get worried about trans temps unless sustained above 220 or anytime greater than 250.